Word wrap

From Rosetta Code
Task
Word wrap
You are encouraged to solve this task according to the task description, using any language you may know.

Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.


Basic task

The basic task is to wrap a paragraph of text in a simple way in your language.

If there is a way to do this that is built-in, trivial, or provided in a standard library, show that. Otherwise implement the minimum length greedy algorithm from Wikipedia.

Show your routine working on a sample of text at two different wrap columns.


Extra credit

Wrap text using a more sophisticated algorithm such as the Knuth and Plass TeX algorithm. If your language provides this, you get easy extra credit, but you must reference documentation indicating that the algorithm is something better than a simple minimimum length algorithm.

If you have both basic and extra credit solutions, show an example where the two algorithms give different results.

360 Assembly

The program uses one ASSIST macro (XPRNT) to keep the code as short as possible. <lang 360asm>* Word wrap 29/01/2017 WORDWRAP CSECT

        USING  WORDWRAP,R13
        B      72(R15)            skip savearea
        DC     17F'0'             savearea
        STM    R14,R12,12(R13)    prolog
        ST     R13,4(R15)         " <-
        ST     R15,8(R13)         " ->
        LR     R13,R15            " addressability         
        MVC    S2,=CL96' '        s2=
        SR     R0,R0
        STH    R0,LENS2           lens2=0
        LA     R8,1               i=1

LOOPI CH R8,=AL2(NTS) do i=1 to hbound(ts)

        BH     ELOOPI             --
        LH     R4,LENS2
        LTR    R4,R4              if lens2=0
        BNZ    IFLENS2            then
        LR     R1,R8                i
        MH     R1,=H'48'
        LA     R14,TS-48(R1)
        MVC    S(48),0(R14)         s=ts(i)
        MVC    S+48(48),=CL48' '
        LA     R12,L'TS             jmax=length(ts)
        B      EIFLENS2           else

IFLENS2 MVC S,=CL96' ' s=

        LA     R6,S                 @s
        LH     R7,LENS2
        LA     R4,S2                @s2
        LH     R5,LENS2
        MVCL   R6,R4              substr(s,1,lens2)=substr(s2,1,lens2)
        LH     R2,LENS2
        LA     R2,1(R2)             lens2+1
        LR     R1,R8                i
        MH     R1,=H'48'
        LA     R14,TS-48(R1)        @ts(i)
        LA     R15,S-1
        AR     R15,R2
        MVC    0(48,R15),0(R14)     substr(s,lens2+1,48)=ts(i)
        LA     R12,L'S              jmax=length(s)

EIFLENS2 MVI OKS2,X'01' oks2=true WHILEOK CLI OKS2,X'01' do while(oks2)

        BNE    EWHILEOK           --
        LR     R9,R12             j=jmax  /*loop1*/

LOOPJ1 CH R9,=H'1' do j=jmax to 1 by -1

        BL     ELOOPJ1            --
        LA     R14,S-1              @s-1
        AR     R14,R9               j
        MVC    CJ(1),0(R14)         cj=substr(s,j,1)
        CLI    CJ,C' '              if cj^=' '
        BNE    ELOOPJ1              then leave j
        BCTR   R9,0                 j=j-1
        B      LOOPJ1             end do j

ELOOPJ1 STH R9,LENS lens=j {length of s}

        MVI    OKJ,X'00'          okj=false  /*loop2*/
        LH     R11,W              js=w
        LH     R4,W
        CH     R4,LENS            if w>lens
        BNH    IFWLENS
        LH     R11,LENS           js=lens

IFWLENS LR R9,R11 j=js LOOPJ2 CH R9,=H'1' do j=js to 1 by -1

        BL     ELOOPJ2            --
        LA     R14,S-1              @s-1
        AR     R14,R9               +j
        MVC    CJ(1),0(R14)         cj=substr(s,j,1)
        CLI    CJ,C' '              if cj=' '
        BNE    ITERJ2               then
        MVI    OKJ,X'01'              okj=true
        B      ELOOPJ2                leave j

ITERJ2 BCTR R9,0 j=j-1

        B      LOOPJ2             end do j

ELOOPJ2 CLI OKJ,X'00' if ^okj

        BNE    ELOOPK
        MVI    OKK,X'00'          okk=false  /*loop3*/
        LH     R10,W              k=w

LOOPK CH R10,LENS do k=w to lens

        BH     ELOOPK             --
        LA     R14,S-1              @s-1
        AR     R14,R10              +k
        MVC    CK(1),0(R14)         ck=substr(s,k,1)
        CLI    CK,C' '              if ck=' '
        BNE    ITERK                then
        MVI    OKK,X'01'              okk=true
        B      ELOOPK                 leave k

ITERK LA R10,1(R10) k=k+1

        B      LOOPK              end do k

ELOOPK MVC S2,=CL96' ' s2=' '

        SR     R0,R0
        STH    R0,LENS2           lens2=0
        MVI    CAS,X'01'          cas=true
        LH     R1,LENS
        CH     R1,W               lens<w
        BL     IFLENSLW
        MVI    CAS,X'00'          cas=false

IFLENSLW CLI CAS,X'00' if ^cas

        BNE    IFNOTCAS           then
        CLI    OKJ,X'01'            if okj
        BNE    NOKJ                 then
        STH    R9,LENS1               lens1=j
        LH     R2,LENS
        SR     R2,R9                  -j
        LA     R2,1(R2)
        STH    R2,LENS2               lens2=lens-j+1
        LA     R6,S1
        LR     R7,R9                  j
        LA     R4,S
        LR     R5,R7
        MVCL   R6,R4                  s1=substr(s,1,j)
        LH     R4,LENS2
        LTR    R4,R4                  if lens2>0
        BNP    ELJLENS2               then
        LA     R6,S2
        LH     R7,LENS2
        LA     R4,S(R9)                 @s(j+1)
        LR     R5,R7
        MVCL   R6,R4                    s2=substr(s,j+1,lens2)
        B      EFJLENS2

ELJLENS2 SR R0,R0 else

        STH    R0,LENS2                 lens2=0

EFJLENS2 B IFNOTCAS NOKJ CLI OKK,X'01' else if okk

        BNE    NOTOKK
        STH    R10,LENS1              lens1=k
        LH     R2,LENS
        SR     R2,R10                 -k
        LA     R2,1(R2)
        STH    R2,LENS2               lens2=lens-k+1
        LA     R6,S1
        LR     R7,R10                 k
        LA     R4,S
        LR     R5,R7
        MVCL   R6,R4                  s1=substr(s,1,k)
        LH     R4,LENS2
        LTR    R4,R4                  if lens2>0
        BNP    ELKLENS2               then
        LA     R6,S2
        LH     R7,LENS2
        LA     R4,S(R10)                @s(k+1)
        LR     R5,R7
        MVCL   R6,R4                    s2=substr(s,k+1,lens2)
        B      EFKLENS2               else

ELKLENS2 SR R0,R0

        STH    R0,LENS2                 lens2=0

EFKLENS2 B IFNOTCAS else NOTOKK LH R0,LENS

        STH    R0,LENS1               lens1=lens
        MVC    S1,S                   s1=s

IFNOTCAS CLI CAS,X'01' if cas

        BNE    ELCAS              then
        LH     R7,LENS
        LA     R7,1(R7)
        LA     R6,S2
        LA     R4,S
        LR     R5,R7
        MVCL   R6,R4                s2=substr(s,1,lens+1)
        LH     R2,LENS
        LA     R2,1(R2)
        STH    R2,LENS2             lens2=lens+1
        B      EFCAS              else

ELCAS LA R6,PG

        LA     R7,L'PG
        LA     R4,S1
        LH     R5,LENS1
        ICM    R5,B'1000',=C' '     padding		 
        MVCL   R6,R4                pg=substr(s1,1,lens1)
        XPRNT  PG,L'PG              put skip list(pg)

EFCAS MVI OKS2,X'00' oks2=false

        LH     R4,LENS2
        CH     R4,W               if lens2>w
        BNH    EFWLENS2           then
        MVI    OKS2,X'01'           oks2=true
        LH     R0,LENS2
        STH    R0,LENS              lens=lens2
        MVC    S,S2                 s=s2

EFWLENS2 B WHILEOK end while EWHILEOK LA R8,1(R8) i=i+1

        B      LOOPI              end do i

ELOOPI LH R4,LENS2

        LTR    R4,R4              if lens2^=0
        BZ     EFLENS2N           then
        LA     R6,PG
        LA     R7,L'PG
        LA     R4,S2
        LH     R5,LENS2
        ICM    R5,B'1000',=C' '     padding		 
        MVCL   R6,R4                pg=substr(s2,1,lens2)
        XPRNT  PG,L'PG              put skip list(pg)

EFLENS2N L R13,4(0,R13) epilog

        LM     R14,R12,12(R13)    " restore
        XR     R15,R15            " rc=0
        BR     R14                exit         

TS DC CL48'In olden times when wishing still helped one,'

        DC     CL48'there lived a king whose daughters were all,'
        DC     CL48'beautiful, but the youngest was so beautiful'
        DC     CL48'that the sun itself, which has seen so much,'
        DC     CL48'was astonished whenever it shone in her face.'
        DC     CL48'Close by the kings castle lay a great dark'
        DC     CL48'forest, and under an old lime tree in the'
        DC     CL48'forest was a well, and when the day was very'
        DC     CL48'warm, the kings child went out into the forest'
        DC     CL48'and sat down by the side of the cool fountain,'
        DC     CL48'and when she was bored she took a golden ball,'
        DC     CL48'and threw it up on high and caught it, and this'
        DC     CL48'ball was her favorite plaything.'

TSE DC 0C NTS EQU (TSE-TS)/L'TS W DC H'36' <-- input width 12<=w<=80 LENS DS H S DS CL96 LENS1 DS H S1 DS CL96 LENS2 DS H S2 DS CL96 OKJ DS X OKK DS X OKS2 DS X CAS DS X CJ DS CL1 CK DS CL1 PG DS CL80

        YREGS
        END    WORDWRAP</lang>
Output:
In olden times when wishing still
helped one, there lived a king
whose daughters were all,
beautiful, but the youngest was so
beautiful that the sun itself,
which has seen so much, was
astonished whenever it shone in her
face. Close by the king's castle
lay a great dark forest, and under
an old lime tree in the forest was
a well, and when the day was very
warm, the king's child went out
into the forest and sat down by the
side of the cool fountain, and when
she was bored she took a golden
ball, and threw it up on high and
caught it, and this ball was her
favorite plaything.

Ada

The specification of a class Word_Wrap.Basic in a package Word_Wrap: <lang Ada>generic

  with procedure Put_Line(Line: String);

package Word_Wrap is

  type Basic(Length_Of_Output_Line: Positive) is tagged private;
  procedure Push_Word(State: in out Basic; Word: String);
  procedure New_Paragraph(State: in out Basic);
  procedure Finish(State: in out Basic);

private

  type Basic(Length_Of_Output_Line: Positive) is tagged record
     Line: String(1 .. Length_Of_Output_Line);
     Size: Natural := 0; -- Line(1 .. Size) is relevant
     Top_Of_Paragraph: Boolean := True;
  end record;

end Word_Wrap;</lang>

The implementation of that package:

<lang Ada>package body Word_Wrap is

  procedure Push_Word(State: in out Basic; Word: String) is
  begin
     if Word'Length + State.Size >= State.Length_Of_Output_Line then
        Put_Line(State.Line(1 .. State.Size));
        State.Line(1 .. Word'Length) := Word; -- may raise CE if Word too long
        State.Size := Word'Length;
     elsif State.Size > 0 then
        State.Line(State.Size+1 .. State.Size+1+Word'Length) := ' ' & Word;
        State.Size := State.Size + 1 + Word'Length;
     else
        State.Line(1 .. Word'Length) := Word;
        State.Size := Word'Length;
     end if;
     State.Top_Of_Paragraph := False;
  end Push_Word;
  procedure New_Paragraph(State: in out Basic) is
  begin
     Finish(State);
     if not State.Top_Of_Paragraph then
        Put_Line("");
        State.Top_Of_Paragraph := True;
     end if;
  end New_Paragraph;
  procedure Finish(State: in out Basic) is
  begin
     if State.Size > 0 then
        Put_Line(State.Line(1 .. State.Size));
        State.Size := 0;
     end if;
  end Finish;

end Word_Wrap;</lang>

Finally, the main program:

<lang Ada>with Ada.Text_IO, Word_Wrap, Ada.Strings.Unbounded, Ada.Command_Line;

procedure Wrap is

  use  Ada.Strings.Unbounded;
  Line: Unbounded_String;
  Word: Unbounded_String;
  function "+"(S: String) return Unbounded_String renames To_Unbounded_String;
  function "-"(U: Unbounded_String) return String renames To_String;
  package IO renames Ada.Text_IO;
  procedure Split(S: Unbounded_String; First, Rest: out Unbounded_String) is
     function Skip_Leading_Spaces(S: String) return String is
     begin
        if S="" then return "";
        elsif S(S'First) = ' ' then return S(S'First+1 .. S'Last);
        else return S;
        end if;
     end Skip_Leading_Spaces;
     Str: String := Skip_Leading_Spaces(-S);
     I: Positive := Str'First;
     J: Natural;
  begin
     -- read nonspaces for First output param
     J := I-1;
     while J < Str'Last and then Str(J+1) /= ' ' loop
        J := J + 1;
     end loop;
     First := + Str(I .. J);
     -- write output param Rest
     Rest  := + Skip_Leading_Spaces(Str(J+1 .. Str'Last));
  end Split;
  procedure Print(S: String) is
  begin
     IO.Put_Line(S);
  end Print;
  package WW is new Word_Wrap(Print);
  Wrapper: WW.Basic(Integer'Value(Ada.Command_Line.Argument(1)));

begin

  while not IO.End_Of_File loop
     Line := +IO.Get_Line;
     if Line = +"" then
        Wrapper.New_Paragraph;
        Line := +IO.Get_Line;
     end if;
     while Line /= +"" loop
        Split(Line, First => Word, Rest => Line);
        Wrapper.Push_Word(-Word);
     end loop;
  end loop;
  Wrapper.Finish;

end Wrap;</lang>

Output:

set to 72 lines (with input picked by cut-and-paste from the task description)

Even today, with proportional fonts and complex layouts, there are still
cases where you need to wrap text at a specified column. The basic task
is to wrap a paragraph of text in a simple way in your language. If
there is a way to do this that is built-in, trivial, or provided in a
standard library, show that. Otherwise implement the minimum length
greedy algorithm from Wikipedia.

Show your routine working on a sample of text at two different wrap
columns.

Extra credit! Wrap text using a more sophisticated algorithm such as the
Knuth and Plass TeX algorithm. If your language provides this, you get
easy extra credit, but you must reference documentation indicating that
the algorithm is something better than a simple minimimum length
algorithm.

If you have both basic and extra credit solutions, show an example where
the two algorithms give different results.

Note that this solution properly deals with multi-paragraph inputs. For more sophisticated algorithms (the extra credit), one could derive a class Word_Wrap.<something> from Word_Wrap.Basic.

AutoHotkey

Basic word-wrap. Formats text that has been copied to the clipboard. <lang AutoHotkey>MsgBox, % "72`n" WrapText(Clipboard, 72) "`n`n80`n" WrapText(Clipboard, 80) return

WrapText(Text, LineLength) { StringReplace, Text, Text, `r`n, %A_Space%, All while (p := RegExMatch(Text, "(.{1," LineLength "})(\s|\R+|$)", Match, p ? p + StrLen(Match) : 1)) Result .= Match1 ((Match2 = A_Space || Match2 = A_Tab) ? "`n" : Match2) return, Result }</lang>

Output:
72
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face.  Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.

80
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face.  Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.

Note: AutoHotkey can automatically word-wrap text in GUI controls such as text, edit boxes, buttons, etc. But, the word-wrap width is based on pixels, not characters.

AWK

Basic word wrap.

<lang awk>function wordwrap_paragraph(p) {

 if ( length(p) < 1 ) return
 
 split(p, words)
 spaceLeft = lineWidth
 line = words[1]
 delete words[1]
 for (i = 1; i <= length(words); i++) {
   word = words[i]
   if ( (length(word) + 1) > spaceLeft ) {
     print line
     line = word
     spaceLeft = lineWidth -  length(word)
   } else {
     spaceLeft -= length(word) + 1
     line = line " " word
   }
 }
 print line

}

BEGIN {

 lineWidth = width
 par = ""

}

/^[ \t]*$/ {

 wordwrap_paragraph(par)
 par = ""

}

!/^[ \t]*$/ {

 par = par " " $0

}

END {

 wordwrap_paragraph(par)

}</lang>

To test it,

awk -f wordwrap.awk -v width=80 < text.txt

BaCon

<lang qbasic>paragraph$ = "In olden times when wishing still helped one," \ " there lived a king whose daughters were all beautiful, but" \ " the youngest was so beautiful that the sun itself, which has" \ " seen so much, was astonished whenever it shone in her face." \ " Close by the king's castle lay a great dark forest, and under" \ " an old lime tree in the forest was a well, and when the day" \ " was very warm, the king's child went out into the forest and" \ " sat down by the side of the cool fountain, and when she was" \ " bored she took a golden ball, and threw it up on high and" \ " caught it, and this ball was her favorite plaything."

PRINT ALIGN$(paragraph$, 72, 0) PRINT ALIGN$(paragraph$, 90, 0)</lang> BaCon has the ALIGN$ function which can align text left-side, right-side, centered or both sides at any given column.

Output:
In olden times when wishing still helped one, there lived a king whose  
daughters were all beautiful, but the youngest was so beautiful that    
the sun itself, which has seen so much, was astonished whenever it      
shone in her face. Close by the king's castle lay a great dark forest,  
and under an old lime tree in the forest was a well, and when the day   
was very warm, the king's child went out into the forest and sat down   
by the side of the cool fountain, and when she was bored she took a     
golden ball, and threw it up on high and caught it, and this ball was   
her favorite plaything.
In olden times when wishing still helped one, there lived a king whose daughters were all 
beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, 
was astonished whenever it shone in her face. Close by the king's castle lay a great dark 
forest, and under an old lime tree in the forest was a well, and when the day was very    
warm, the king's child went out into the forest and sat down by the side of the cool      
fountain, and when she was bored she took a golden ball, and threw it up on high and      
caught it, and this ball was her favorite plaything.

Batch File

Basic word wrap. <lang dos>@echo off

set "input=Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur!" rem call the function (the second parameter is the line width) call :wrap "%input%" 40 echo( call :wrap "%input%" 70 pause>nul exit /b 0

The procedure
wrap

set "line=" set "tmp_str=%~1" set /a "width=%2", "width-=1"

proc_loop

rem check if we are done already if "%tmp_str%"=="" (

   setlocal enabledelayedexpansion
   if defined line echo(!line!
   endlocal & goto :EOF

)

rem not yet done, so take a word and process it for /f "tokens=1,* delims= " %%A in ("%tmp_str%") do (

   set "word=%%A"
   set "tmp_str=%%B"
   setlocal enabledelayedexpansion
   if "!line!"=="" (set "testline=!word!") else (set "testline=!line! !word!")
   if "!testline:~%width%,1!" == "" (
       set "line=!testline!"
   ) else (
       echo(!line!
       set "line=!word!"
   )

) endlocal & set "line=%line%" goto proc_loop</lang>

Output:
Lorem ipsum dolor sit amet, consectetur
adipiscing elit. Donec a diam lectus.
Sed sit amet ipsum mauris. Maecenas
congue ligula ac quam viverra nec
consectetur ante hendrerit. Donec et
mollis dolor. Praesent et diam eget
libero egestas mattis sit amet vitae
augue. Nam tincidunt congue enim, ut
porta lorem lacinia consectetur!

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam
lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam
viverra nec consectetur ante hendrerit. Donec et mollis dolor.
Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam
tincidunt congue enim, ut porta lorem lacinia consectetur!

Bracmat

<lang bracmat>( str

   $ ( "In olden times when wishing still helped one, there lived a king "
       "whose daughters were all beautiful, but the youngest was so beautiful "
       "that the sun itself, which has seen so much, was astonished whenever "
       "it shone in her face.  Close by the king's castle lay a great dark "
       "forest, and under an old lime tree in the forest was a well, and when "
       "the day was very warm, the king's child went out into the forest and "
       "sat down by the side of the cool fountain, and when she was bored she "
       "took a golden ball, and threw it up on high and caught it, and this "
       "ball was her favorite plaything."
     )
 : ?Text

& ( wrap

 =   txt length line output q rem
   .   !arg:(?txt.?length)
     & :?output
     &   whl
       ' ( @( str$!txt
            :   ?line
                (" " %?lastword [?q " " ?rem&!q:~<!length)
            )
         & !lastword " " !rem:?txt
         & !output !line \n:?output
         )
     & str$(!output !txt)
 )

& out$(str$("72 columns:\n" wrap$(!Text.72))) & out$(str$("\n80 columns:\n" wrap$(!Text.80))) );</lang>

Output:
72 columns:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that
the sun itself, which has seen so much, was astonished whenever it
shone in her face.  Close by the king's castle lay a great dark forest,
and under an old lime tree in the forest was a well, and when the day
was very warm, the king's child went out into the forest and sat down
by the side of the cool fountain, and when she was bored she took a
golden ball, and threw it up on high and caught it, and this ball was
her favorite plaything.

80 columns:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the sun
itself, which has seen so much, was astonished whenever it shone in her face.
 Close by the king's castle lay a great dark forest, and under an old lime tree
in the forest was a well, and when the day was very warm, the king's child went
out into the forest and sat down by the side of the cool fountain, and when she
was bored she took a golden ball, and threw it up on high and caught it, and
this ball was her favorite plaything.

C

<lang c>#include <stdio.h>

  1. include <stdlib.h>
  2. include <string.h>
  3. include <ctype.h>

/* nonsensical hyphens to make greedy wrapping method look bad */ const char *string = "In olden times when wishing still helped one, there lived a king " "whose daughters were all beautiful, but the youngest was so beautiful " "that the sun itself, which has seen so much, was astonished whenever " "it shone-in-her-face. Close-by-the-king's castle lay a great dark " "forest, and under an old lime-tree in the forest was a well, and when " "the day was very warm, the king's child went out into the forest and " "sat down by the side of the cool-fountain, and when she was bored she " "took a golden ball, and threw it up on high and caught it, and this " "ball was her favorite plaything.";

/* Each but the last of wrapped lines comes with some penalty as the square of the diff between line length and desired line length. If the line is longer than desired length, the penalty is multiplied by 100. This pretty much prohibits the wrapping routine from going over right margin. If is ok to exceed the margin just a little, something like 20 or 40 will do.

Knuth uses a per-paragraph penalty for line-breaking in TeX, which is-- unlike what I have here--probably bug-free.

  • /
  1. define PENALTY_LONG 100
  2. define PENALTY_SHORT 1

typedef struct word_t { const char *s; int len; } *word;

word make_word_list(const char *s, int *n) { int max_n = 0; word words = 0;

*n = 0; while (1) { while (*s && isspace(*s)) s++; if (!*s) break;

if (*n >= max_n) { if (!(max_n *= 2)) max_n = 2; words = realloc(words, max_n * sizeof(*words)); } words[*n].s = s; while (*s && !isspace(*s)) s++; words[*n].len = s - words[*n].s; (*n) ++; }

return words; }

int greedy_wrap(word words, int count, int cols, int *breaks) { int score = 0, line, i, j, d;

i = j = line = 0; while (1) { if (i == count) { breaks[j++] = i; break; }

if (!line) { line = words[i++].len; continue; }

if (line + words[i].len < cols) { line += words[i++].len + 1; continue; }

breaks[j++] = i; if (i < count) { d = cols - line; if (d > 0) score += PENALTY_SHORT * d * d; else if (d < 0) score += PENALTY_LONG * d * d; }

line = 0; } breaks[j++] = 0;

return score; }

/* tries to make right margin more even; pretty sure there's an off-by-one bug here somewhere */ int balanced_wrap(word words, int count, int cols, int *breaks) { int *best = malloc(sizeof(int) * (count + 1));

/* do a greedy wrap to have some baseline score to work with, else we'll end up with O(2^N) behavior */ int best_score = greedy_wrap(words, count, cols, breaks);

void test_wrap(int line_no, int start, int score) { int line = 0, current_score = -1, d;

while (start <= count) { if (line) line ++; line += words[start++].len; d = cols - line; if (start < count || d < 0) { if (d > 0) current_score = score + PENALTY_SHORT * d * d; else current_score = score + PENALTY_LONG * d * d; } else { current_score = score; }

if (current_score >= best_score) { if (d <= 0) return; continue; }

best[line_no] = start; test_wrap(line_no + 1, start, current_score); } if (current_score >= 0 && current_score < best_score) { best_score = current_score; memcpy(breaks, best, sizeof(int) * (line_no)); } } test_wrap(0, 0, 0); free(best);

return best_score; }

void show_wrap(word list, int count, int *breaks) { int i, j; for (i = j = 0; i < count && breaks[i]; i++) { while (j < breaks[i]) { printf("%.*s", list[j].len, list[j].s); if (j < breaks[i] - 1) putchar(' '); j++; } if (breaks[i]) putchar('\n'); } }

int main(void) { int len, score, cols; word list = make_word_list(string, &len); int *breaks = malloc(sizeof(int) * (len + 1));

cols = 80; score = greedy_wrap(list, len, cols, breaks); printf("\n== greedy wrap at %d (score %d) ==\n\n", cols, score); show_wrap(list, len, breaks);

score = balanced_wrap(list, len, cols, breaks); printf("\n== balanced wrap at %d (score %d) ==\n\n", cols, score); show_wrap(list, len, breaks);


cols = 32; score = greedy_wrap(list, len, cols, breaks); printf("\n== greedy wrap at %d (score %d) ==\n\n", cols, score); show_wrap(list, len, breaks);

score = balanced_wrap(list, len, cols, breaks); printf("\n== balanced wrap at %d (score %d) ==\n\n", cols, score); show_wrap(list, len, breaks);

return 0; }</lang>

C#

Greedy algorithm: <lang csharp>namespace RosettaCode.WordWrap {

   using System;
   using System.Collections.Generic;
   internal static class Program
   {
       private const string LoremIpsum = @"

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas varius sapien vel purus hendrerit vehicula. Integer hendrerit viverra turpis, ac sagittis arcu pharetra id. Sed dapibus enim non dui posuere sit amet rhoncus tellus consectetur. Proin blandit lacus vitae nibh tincidunt cursus. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nam tincidunt purus at tortor tincidunt et aliquam dui gravida. Nulla consectetur sem vel felis vulputate et imperdiet orci pharetra. Nam vel tortor nisi. Sed eget porta tortor. Aliquam suscipit lacus vel odio faucibus tempor. Sed ipsum est, condimentum eget eleifend ac, ultricies non dui. Integer tempus, nunc sed venenatis feugiat, augue orci pellentesque risus, nec pretium lacus enim eu nibh.";

       private static void Main()
       {
           foreach (var lineWidth in new[] { 72, 80 })
           {
               Console.WriteLine(new string('-', lineWidth));
               Console.WriteLine(Wrap(LoremIpsum, lineWidth));
           }
       }
       private static string Wrap(string text, int lineWidth)
       {
           return string.Join(string.Empty,
                              Wrap(
                                  text.Split(new char[0],
                                             StringSplitOptions
                                                 .RemoveEmptyEntries),
                                  lineWidth));
       }
       private static IEnumerable<string> Wrap(IEnumerable<string> words,
                                               int lineWidth)
       {
           var currentWidth = 0;
           foreach (var word in words)
           {
               if (currentWidth != 0)
               {
                   if (currentWidth + word.Length < lineWidth)
                   {
                       currentWidth++;
                       yield return " ";
                   }
                   else
                   {
                       currentWidth = 0;
                       yield return Environment.NewLine;
                   }
               }
               currentWidth += word.Length;
               yield return word;
           }
       }
   }

}</lang>

Output:
------------------------------------------------------------------------
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas varius
sapien vel purus hendrerit vehicula. Integer hendrerit viverra turpis,
ac sagittis arcu pharetra id. Sed dapibus enim non dui posuere sit amet
rhoncus tellus consectetur. Proin blandit lacus vitae nibh tincidunt
cursus. Cum sociis natoque penatibus et magnis dis parturient montes,
nascetur ridiculus mus. Nam tincidunt purus at tortor tincidunt et
aliquam dui gravida. Nulla consectetur sem vel felis vulputate et
imperdiet orci pharetra. Nam vel tortor nisi. Sed eget porta tortor.
Aliquam suscipit lacus vel odio faucibus tempor. Sed ipsum est,
condimentum eget eleifend ac, ultricies non dui. Integer tempus, nunc
sed venenatis feugiat, augue orci pellentesque risus, nec pretium lacus
enim eu nibh.
--------------------------------------------------------------------------------
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas varius sapien
vel purus hendrerit vehicula. Integer hendrerit viverra turpis, ac sagittis arcu
pharetra id. Sed dapibus enim non dui posuere sit amet rhoncus tellus
consectetur. Proin blandit lacus vitae nibh tincidunt cursus. Cum sociis natoque
penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nam tincidunt
purus at tortor tincidunt et aliquam dui gravida. Nulla consectetur sem vel
felis vulputate et imperdiet orci pharetra. Nam vel tortor nisi. Sed eget porta
tortor. Aliquam suscipit lacus vel odio faucibus tempor. Sed ipsum est,
condimentum eget eleifend ac, ultricies non dui. Integer tempus, nunc sed
venenatis feugiat, augue orci pellentesque risus, nec pretium lacus enim eu
nibh.

C++

Basic task.

Translation of: Go

<lang cpp>#include <iostream>

  1. include <sstream>
  2. include <string>

const char *text = {

   "In olden times when wishing still helped one, there lived a king "
   "whose daughters were all beautiful, but the youngest was so beautiful "
   "that the sun itself, which has seen so much, was astonished whenever "
   "it shone in her face.  Close by the king's castle lay a great dark "
   "forest, and under an old lime tree in the forest was a well, and when "
   "the day was very warm, the king's child went out into the forest and "
   "sat down by the side of the cool fountain, and when she was bored she "
   "took a golden ball, and threw it up on high and caught it, and this "
   "ball was her favorite plaything."

};

std::string wrap(const char *text, size_t line_length = 72) {

   std::istringstream words(text);
   std::ostringstream wrapped;
   std::string word;
   if (words >> word) {
       wrapped << word;
       size_t space_left = line_length - word.length();
       while (words >> word) {
           if (space_left < word.length() + 1) {
               wrapped << '\n' << word;
               space_left = line_length - word.length();
           } else {
               wrapped << ' ' << word;
               space_left -= word.length() + 1;
           }
       }
   }
   return wrapped.str();

}

int main() {

   std::cout << "Wrapped at 72:\n" << wrap(text) << "\n\n";
   std::cout << "Wrapped at 80:\n" << wrap(text, 80) << "\n";

}</lang>

Output:
Wrapped at 72:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face. Close by the king's castle lay a great dark forest, and under
an old lime tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.

Wrapped at 80:
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face. Close by the
king's castle lay a great dark forest, and under an old lime tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.

Clojure

<lang Clojure>;; Wrap line naive version (defn wrap-line [size text]

 (loop [left size line [] lines []
        words (clojure.string/split text #"\s+")]
   (if-let [word (first words)]
     (let [wlen (count word)
           spacing (if (== left size) "" " ")
           alen (+ (count spacing) wlen)]
       (if (<= alen left)
         (recur (- left alen) (conj line spacing word) lines (next words))
         (recur (- size wlen) [word] (conj lines (apply str line)) (next words))))
     (when (seq line)
       (conj lines (apply str line))))))</lang>

<lang Clojure>;; Wrap line base on regular expression (defn wrap-line [size text]

 (re-seq (re-pattern (str ".{1," size "}\\s|.{1," size "}"))
         (clojure.string/replace text #"\n" " ")))</lang>

<lang Clojure>;; cl-format based version (defn wrap-line [size text]

 (clojure.pprint/cl-format nil (str "~{~<~%~1," size ":;~A~> ~}") (clojure.string/split text #" ")))</lang>

Usage example : <lang Clojure>(def text "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.")

(doseq [line (wrap-line 72 text)]

 (println line))</lang>
Output:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face. Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.

Common Lisp

<lang Lisp>;; Greedy wrap line

(defun greedy-wrap (str width)

 (setq str (concatenate 'string str " ")) ; add sentinel
 (do* ((len (length str))
       (lines nil)
       (begin-curr-line 0)
       (prev-space 0 pos-space)
       (pos-space (position #\Space str) (when (< (1+ prev-space) len) (position #\Space str :start (1+ prev-space)))) )
      ((null pos-space) (progn (push (subseq str begin-curr-line (1- len)) lines) (nreverse lines)) )
   (when (> (- pos-space begin-curr-line) width)
     (push (subseq str begin-curr-line prev-space) lines)
     (setq begin-curr-line (1+ prev-space)) )))

</lang>

Output:
(setq str "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but
 the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her
 face. Close by the king's castle lay a great dark forest, and under an old lime tree in the forest was a well, and
 when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain,
 and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite
 plaything.") 

(greedy-wrap str 72)

("In olden times when wishing still helped one, there lived a king whose"
 "daughters were all beautiful, but the youngest was so beautiful that the"
 "sun itself, which has seen so much, was astonished whenever it shone in"
 "her face. Close by the king's castle lay a great dark forest, and under"
 "an old lime tree in the forest was a well, and when the day was very"
 "warm, the king's child went out into the forest and sat down by the side"
 "of the cool fountain, and when she was bored she took a golden ball, and"
 "threw it up on high and caught it, and this ball was her favorite"
 "plaything.")
 
(greedy-wrap str 80)

("In olden times when wishing still helped one, there lived a king whose daughters"
 "were all beautiful, but the youngest was so beautiful that the sun itself, which"
 "has seen so much, was astonished whenever it shone in her face. Close by the"
 "king's castle lay a great dark forest, and under an old lime tree in the forest"
 "was a well, and when the day was very warm, the king's child went out into the"
 "forest and sat down by the side of the cool fountain, and when she was bored she"
 "took a golden ball, and threw it up on high and caught it, and this ball was her"
 "favorite plaything.")

D

Standard Version

<lang d>void main() {

   immutable frog =

"In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.";

   import std.stdio, std.string;
   foreach (width; [72, 80])
       writefln("Wrapped at %d:\n%s\n", width, frog.wrap(width));

}</lang>

Output:
Wrapped at 72:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face. Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.


Wrapped at 80:
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face. Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.

An Implementation

Basic algorithm. The text splitting is lazy.

Translation of: Go

<lang d>import std.algorithm;

string wrap(in string text, in int lineWidth) {

   auto words = text.splitter;
   if (words.empty) return null;
   string wrapped = words.front;
   words.popFront();
   int spaceLeft = lineWidth - wrapped.length;
   foreach (word; words)
       if (word.length + 1 > spaceLeft) {
           wrapped ~= "\n" ~ word;
           spaceLeft = lineWidth - word.length;
       } else {
           wrapped ~= " " ~ word;
           spaceLeft -= 1 + word.length;
       }
   return wrapped;

}

void main() {

   immutable frog =

"In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.";

   import std.stdio;
   foreach (width; [72, 80])
       writefln("Wrapped at %d:\n%s\n", width, frog.wrap(width));

}</lang>

Output:
Wrapped at 72:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face. Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.

Wrapped at 80:
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face. Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.

Elena

ELENA 4.x : <lang elena>import extensions; import system'routines; import extensions'text;

string text =

   "In olden times when wishing still helped one, there lived a king 

whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.";

extension wrapOp {

   wrap(int lineWidth)
   {
       int currentWidth := 0;

       ^ TokenEnumerator 
           .new(self) 
           .selectBy:(word)
           {
               currentWidth += word.Length;
               if (currentWidth > lineWidth)
               {
                   currentWidth := word.Length + 1;

                   ^ newLine + word + " "
               }
               else
               {
                   currentWidth += 1;

                   ^  word + " "
               }
           }
           .summarize(new StringWriter())
   }

}

public program() {

   console.printLine(new StringWriter("-", 72));
   console.printLine(text.wrap(72));
   console.printLine(new StringWriter("-", 80));
   console.printLine(text.wrap(80));

}</lang>

Output:
------------------------------------------------------------------------
In olden times when wishing still helped one, there lived a king whose 
daughters were all beautiful, but the youngest was so beautiful that the 
sun itself, which has seen so much, was astonished whenever it shone in 
her face. Close by the king's castle lay a great dark forest, and under 
an old lime tree in the forest was a well, and when the day was very 
warm, the king's child went out into the forest and sat down by the side 
of the cool fountain, and when she was bored she took a golden ball, and 
threw it up on high and caught it, and this ball was her favorite 
plaything. 
--------------------------------------------------------------------------------
In olden times when wishing still helped one, there lived a king whose daughters 
were all beautiful, but the youngest was so beautiful that the sun itself, which 
has seen so much, was astonished whenever it shone in her face. Close by the 
king's castle lay a great dark forest, and under an old lime tree in the forest 
was a well, and when the day was very warm, the king's child went out into the 
forest and sat down by the side of the cool fountain, and when she was bored she 
took a golden ball, and threw it up on high and caught it, and this ball was her 
favorite plaything. 

Elixir

Translation of: Erlang

<lang elixir>defmodule Word_wrap do

 def paragraph( string, max_line_length ) do
   [word | rest] = String.split( string, ~r/\s+/, trim: true )
   lines_assemble( rest, max_line_length, String.length(word), word, [] )
     |> Enum.join( "\n" )
 end
 
 defp lines_assemble( [], _, _, line, acc ), do: [line | acc] |> Enum.reverse
 defp lines_assemble( [word | rest], max, line_length, line, acc ) do
   if line_length + 1 + String.length(word) > max do
     lines_assemble( rest, max, String.length(word), word, [line | acc] )
   else
     lines_assemble( rest, max, line_length + 1 + String.length(word), line <> " " <> word, acc )
   end
 end

end

text = """ Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column. The basic task is to wrap a paragraph of text in a simple way in your language. If there is a way to do this that is built-in, trivial, or provided in a standard library, show that. Otherwise implement the minimum length greedy algorithm from Wikipedia. """ Enum.each([72, 80], fn len ->

 IO.puts String.duplicate("-", len)
 IO.puts Word_wrap.paragraph(text, len)

end)</lang>

Output:
------------------------------------------------------------------------
Even today, with proportional fonts and complex layouts, there are still
cases where you need to wrap text at a specified column. The basic task
is to wrap a paragraph of text in a simple way in your language. If
there is a way to do this that is built-in, trivial, or provided in a
standard library, show that. Otherwise implement the minimum length
greedy algorithm from Wikipedia.
--------------------------------------------------------------------------------
Even today, with proportional fonts and complex layouts, there are still cases
where you need to wrap text at a specified column. The basic task is to wrap a
paragraph of text in a simple way in your language. If there is a way to do this
that is built-in, trivial, or provided in a standard library, show that.
Otherwise implement the minimum length greedy algorithm from Wikipedia.

Erlang

<lang Erlang> -module( word_wrap ).

-export( [paragraph/2, task/0] ).

paragraph( String, Max_line_length ) -> Lines = lines( string:tokens(String, " "), Max_line_length ), string:join( Lines, "\n" ).

task() -> Paragraph = "Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column. The basic task is to wrap a paragraph of text in a simple way in your language. If there is a way to do this that is built-in, trivial, or provided in a standard library, show that. Otherwise implement the minimum length greedy algorithm from Wikipedia.", io:fwrite( "~s~n~n", [paragraph(Paragraph, 72)] ), io:fwrite( "~s~n~n", [paragraph(Paragraph, 80)] ).


lines( [Word | T], Max_line_length ) -> {Max_line_length, _Length, Last_line, Lines} = lists:foldl( fun lines_assemble/2, {Max_line_length, erlang:length(Word), Word, []}, T ), lists:reverse( [Last_line | Lines] ).

lines_assemble( Word, {Max, Line_length, Line, Acc} ) when erlang:length(Word) + Line_length > Max -> {Max, erlang:length(Word), Word, [Line | Acc]}; lines_assemble( Word, {Max, Line_length, Line, Acc} ) -> {Max, Line_length + 1 + erlang:length(Word), Line ++ " " ++ Word, Acc}. </lang>

Output:
15> word_wrap:task().
Even today, with proportional fonts and complex layouts, there are still
cases where you need to wrap text at a specified column. The basic task
is to wrap a paragraph of text in a simple way in your language. If there
is a way to do this that is built-in, trivial, or provided in a standard
library, show that. Otherwise implement the minimum length greedy
algorithm from Wikipedia.

Even today, with proportional fonts and complex layouts, there are still cases
where you need to wrap text at a specified column. The basic task is to wrap a
paragraph of text in a simple way in your language. If there is a way to do this
that is built-in, trivial, or provided in a standard library, show that.
Otherwise implement the minimum length greedy algorithm from Wikipedia.

F#

Translation of: C#

<lang fsharp>open System

let LoremIpsum = " Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas varius sapien vel purus hendrerit vehicula. Integer hendrerit viverra turpis, ac sagittis arcu pharetra id. Sed dapibus enim non dui posuere sit amet rhoncus tellus consectetur. Proin blandit lacus vitae nibh tincidunt cursus. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nam tincidunt purus at tortor tincidunt et aliquam dui gravida. Nulla consectetur sem vel felis vulputate et imperdiet orci pharetra. Nam vel tortor nisi. Sed eget porta tortor. Aliquam suscipit lacus vel odio faucibus tempor. Sed ipsum est, condimentum eget eleifend ac, ultricies non dui. Integer tempus, nunc sed venenatis feugiat, augue orci pellentesque risus, nec pretium lacus enim eu nibh."

let Wrap words lineWidth =

   let rec loop words currentWidth = seq {
       match (words : string list) with
       | word :: rest -> 
           let (stuff, pos) =
               if currentWidth > 0 then
                   if currentWidth + word.Length < lineWidth then
                       (" ", (currentWidth + 1))
                   else
                       ("\n", 0)
               else ("", 0)
           yield stuff + word
           yield! loop rest (pos + word.Length)
       | _ -> ()
   }
   loop words 0

[<EntryPoint>] let main argv =

   for n in [72; 80] do
       printfn "%s" (String('-', n))
       let l = Seq.toList (LoremIpsum.Split((null:char[]), StringSplitOptions.RemoveEmptyEntries))
       Wrap l n |> Seq.iter (printf "%s")
       printfn ""
   0</lang>
Output:
------------------------------------------------------------------------
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas varius
sapien vel purus hendrerit vehicula. Integer hendrerit viverra turpis,
ac sagittis arcu pharetra id. Sed dapibus enim non dui posuere sit amet
rhoncus tellus consectetur. Proin blandit lacus vitae nibh tincidunt
cursus. Cum sociis natoque penatibus et magnis dis parturient montes,
nascetur ridiculus mus. Nam tincidunt purus at tortor tincidunt et
aliquam dui gravida. Nulla consectetur sem vel felis vulputate et
imperdiet orci pharetra. Nam vel tortor nisi. Sed eget porta tortor.
Aliquam suscipit lacus vel odio faucibus tempor. Sed ipsum est,
condimentum eget eleifend ac, ultricies non dui. Integer tempus, nunc
sed venenatis feugiat, augue orci pellentesque risus, nec pretium lacus
enim eu nibh.
--------------------------------------------------------------------------------
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas varius sapien
vel purus hendrerit vehicula. Integer hendrerit viverra turpis, ac sagittis arcu
pharetra id. Sed dapibus enim non dui posuere sit amet rhoncus tellus
consectetur. Proin blandit lacus vitae nibh tincidunt cursus. Cum sociis natoque
penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nam tincidunt
purus at tortor tincidunt et aliquam dui gravida. Nulla consectetur sem vel
felis vulputate et imperdiet orci pharetra. Nam vel tortor nisi. Sed eget porta
tortor. Aliquam suscipit lacus vel odio faucibus tempor. Sed ipsum est,
condimentum eget eleifend ac, ultricies non dui. Integer tempus, nunc sed
venenatis feugiat, augue orci pellentesque risus, nec pretium lacus enim eu
nibh.

Factor

<lang factor>USE: wrap.strings IN: scratchpad "Most languages in widespread use today are applicative languages

the central construct in the language is some form of function call, where a f

unction is applied to a set of parameters, where each parameter is itself the re sult of a function call, the name of a variable, or a constant. In stack languag es, a function call is made by simply writing the name of the function; the para meters are implicit, and they have to already be on the stack when the call is m ade. The result of the function call (if any) is then left on the stack after th e function returns, for the next function to consume, and so on. Because functio ns are invoked simply by mentioning their name without any additional syntax, Fo rth and Factor refer to functions as words, because in the syntax they really ar e just words." [ 60 wrap-string print nl ] [ 45 wrap-string print ] bi</lang>

Output:
Most languages in widespread use today are applicative
languages: the central construct in the language is some
form of function call, where a function is applied to a set
of parameters, where each parameter is itself the result of
a function call, the name of a variable, or a constant. In
stack languages, a function call is made by simply writing
the name of the function; the parameters are implicit, and
they have to already be on the stack when the call is made.
The result of the function call (if any) is then left on
the stack after the function returns, for the next function
to consume, and so on. Because functions are invoked simply
by mentioning their name without any additional syntax,
Forth and Factor refer to functions as words, because in the
syntax they really are just words.

Most languages in widespread use today are
applicative languages: the central construct
in the language is some form of function
call, where a function is applied to a set
of parameters, where each parameter is itself
the result of a function call, the name of a
variable, or a constant. In stack languages,
a function call is made by simply writing
the name of the function; the parameters are
implicit, and they have to already be on the
stack when the call is made. The result of
the function call (if any) is then left on
the stack after the function returns, for the
next function to consume, and so on. Because
functions are invoked simply by mentioning
their name without any additional syntax,
Forth and Factor refer to functions as words,
because in the syntax they really are just
words.

Forth

<lang forth>\ wrap text \ usage: gforth wrap.f in.txt 72

0. argc @ 1- arg >number 2drop drop constant maxLine

.wrapped ( buf len -- )
 begin
   dup maxLine >
 while
   over maxLine
   begin 1- 2dup + c@ bl = until
   dup 1+ >r
   begin 1- 2dup + c@ bl <> until
   1+ type cr
   r> /string
 repeat type cr ;
strip-nl ( buf len -- )
 bounds do
   i c@ 10 = if bl i c! then
 loop ;

argc @ 2 - arg slurp-file 2dup strip-nl .wrapped bye</lang>

Fortran

Early Fortran provided no facility for manipulating text until the A format code was introduced by Fortran 4 that allowed characters to be read into variables, which could then be manipulated and written out. F77 introduced the CHARACTER data type which however did not have a notion of a variable-length string, other than via the programmer keeping track with auxiliary variables. F90 enabled the introduction via user-written functions and data types of a string-like facility, whereby a CHARACTER type variable would be resized on assignment. F95 formalised this facility as a part of the language.

There are no facilities for "flowing" text on output according to a specified width, though various direct methods are possible. For instance, given a variable containing thousands of characters, <lang Fortran> CHARACTER*12345 TEXT

      ...
     DO I = 0,120
       WRITE (6,*) TEXT(I*80 + 1:(I + 1)*80)
     END DO</lang>

would write forth the text with eighty characters per line, paying no attention to the content when it splits a line.

The following is in the style of F77 except for the use of the MODULE facility to simplify the usage of auxiliary variables. Otherwise, if there is not to be a simple mainline only, scratchpads would have to be shared via COMMON or the proliferation of a tedious number of parameters. The specification calls for the flowing of a single paragraph of text, but this routine is based on one written in the 1980s for the printing of programme source files (in Fortran or pl/i) whereby large blocks of comments would be recognised and re-flowed so as to fill more of the width of a 132-column lineprinter, thus allowing a broader canvas for documentation and yet, whenever there were changes, the source file did not have to be reformatted each time.

The basic ploy is that FLOW receives a wad of text and sends it forth without exceeding a specified WIDTH, holding any tail end until the next blob is supplied to be tacked on the end, with a separating space supplied. However, if a blob starts with a space this is deemed to be the start of a new paragraph, so any waiting text is rolled first even if a short line. To flush out any waiting text at the end, invoke FLOW with a blank (or null) parameter.

The source-listing programmes simply appended the incoming text to the end of the scratchpad, knowing that source files do not present long records, but here an incoming text may be much larger than any reasonable scratchpad so there is assessment of the available space first. Choosing a cut position is problematic. The scheme here is to split at spaces only; a more accomplished method might classify letters, digits and decimal points as being sequences that ought not be split. And should it be O'-hara or O-'hara? Still more difficult is proper hyphenation: des-ert (noun) or de-sert (verb) - the grammar of human languages being non-computable.

Should there be no suitable split in the fragment being appended, then, arbitrarily, if that fragment is short then it is not appended: the line is rolled with trailing spaces. But if it has more than six characters, it will be placed and a crude chop made. <lang Fortran>

     MODULE RIVERRUN	!Schemes for re-flowing wads of text to a specified line length.
      INTEGER BL,BLIMIT,BM	!Fingers for the scratchpad.
      PARAMETER (BLIMIT = 222)	!This should be enough for normal widths.
      CHARACTER*(BLIMIT) BUMF	!The scratchpad, accumulating text.
      INTEGER OUTBUMF		!Output unit number.
      DATA OUTBUMF/0/		!Thus detect inadequate initialisation.
      PRIVATE BL,BLIMIT,BM	!These names are not so unusual
      PRIVATE BUMF,OUTBUMF	!That no other routine will use them.
      CONTAINS
      INTEGER FUNCTION LSTNB(TEXT)  !Sigh. Last Not Blank.

Concocted yet again by R.N.McLean (whom God preserve) December MM. Code checking reveals that the Compaq compiler generates a copy of the string and then finds the length of that when using the latter-day intrinsic LEN_TRIM. Madness! Can't DO WHILE (L.GT.0 .AND. TEXT(L:L).LE.' ') !Control chars. regarded as spaces. Curse the morons who think it good that the compiler MIGHT evaluate logical expressions fully. Crude GO TO rather than a DO-loop, because compilers use a loop counter as well as updating the index variable. Comparison runs of GNASH showed a saving of ~3% in its mass-data reading through the avoidance of DO in LSTNB alone. Crappy code for character comparison of varying lengths is avoided by using ICHAR which is for single characters only. Checking the indexing of CHARACTER variables for bounds evoked astounding stupidities, such as calculating the length of TEXT(L:L) by subtracting L from L! Comparison runs of GNASH showed a saving of ~25-30% in its mass data scanning for this, involving all its two-dozen or so single-character comparisons, not just in LSTNB.

       CHARACTER*(*),INTENT(IN):: TEXT	!The bumf. If there must be copy-in, at least there need not be copy back.
       INTEGER L		!The length of the bumf.
        L = LEN(TEXT)		!So, what is it?
   1    IF (L.LE.0) GO TO 2	!Are we there yet?
        IF (ICHAR(TEXT(L:L)).GT.ICHAR(" ")) GO TO 2	!Control chars are regarded as spaces also.
        L = L - 1		!Step back one.
        GO TO 1		!And try again.
   2    LSTNB = L		!The last non-blank, possibly zero.
       RETURN			!Unsafe to use LSTNB as a variable.
      END FUNCTION LSTNB	!Compilers can bungle it.
       SUBROUTINE STARTFLOW(OUT,WIDTH)	!Preparation.
        INTEGER OUT	!Output device.
        INTEGER WIDTH	!Width limit.
         OUTBUMF = OUT		!Save these
         BM = WIDTH		!So that they don't have to be specified every time.
         IF (BM.GT.BLIMIT) STOP "Too wide!"	!Alas, can't show the values BLIMIT and WIDTH.
         BL = 0		!No text already waiting in BUMF
       END SUBROUTINE STARTFLOW!Simple enough.
       SUBROUTINE FLOW(TEXT)	!Add to the ongoing BUMF.
        CHARACTER*(*) TEXT	!The text to append.
        INTEGER TL		!Its last non-blank.
        INTEGER T1,T2		!Fingers to TEXT.
        INTEGER L		!A length.
         IF (OUTBUMF.LT.0) STOP "Call STARTFLOW first!"	!Paranoia.
         TL = LSTNB(TEXT)	!No trailing spaces, please.
         IF (TL.LE.0) THEN	!A blank (or null) line?
           CALL FLUSH		!Thus end the paragraph.
           RETURN		!Perhaps more text will follow, later.
         END IF		!Curse the (possible) full evaluation of .OR. expressions!
         IF (TEXT(1:1).LE." ") CALL FLUSH	!This can't be checked above in case LEN(TEXT) = 0.

Chunks of TEXT are to be appended to BUMF.

         T1 = 1		!Start at the start, blank or not.
  10     IF (BL.GT.0) THEN	!If there is text waiting in BUMF,
           BL = BL + 1		!Then this latest text is to be appended
           BUMF(BL:BL) = " "	!After one space.
         END IF		!So much for the join.

Consider the amount of text to be placed, TEXT(T1:TL)

         L = TL - T1 + 1	!Length of text to be placed.
         IF (BM - BL .GE. L) THEN	!Sufficient space available?
           BUMF(BL + 1:BM + L) = TEXT(T1:TL)	!Yes. Copy all the remaining text.
           BL = BL + L				!Advance the finger.
           IF (BL .GE. BM - 1) CALL FLUSH	!If there is no space for an addendum.
           RETURN				!Done.
         END IF		!Otherwise, there is an overhang.

Calculate the available space up to the end of a line. BUMF(BL + 1:BM)

         L = BM - BL		!The number of characters available in BUMF.
         T2 = T1 + L		!Finger the first character beyond the take.
         IF (TEXT(T2:T2) .LE. " ") GO TO 12	!A splitter character? Happy chance!
         T2 = T2 - 1		!Thus the last character of TEXT that could be placed in BUMF.
  11     IF (TEXT(T2:T2) .GT. " ") THEN	!Are we looking at a space yet?
           T2 = T2 - 1				!No. step back one.
           IF (T2 .GT. T1) GO TO 11		!And try again, if possible.
           IF (L .LE. 6) THEN	!No splitter found. For short appendage space,
             CALL FLUSH		!Starting a new line gives more scope.
             GO TO 10			!At the cost of spaces at the end.
           END IF		!But splitting words is unsavoury too.
           T2 = T1 + L - 1		!Alas, no split found.
         END IF		!So the end-of-line will force a split.
         L = T2 - T1 + 1	!The length I settle on.
  12     BUMF(BL + 1:BL + L) = TEXT(T1:T1 + L - 1)	!I could add a hyphen at the arbitrary chop...
         BL = BL + L		!The last placed.
         CALL FLUSH		!The line being full.

Consider what the flushed line didn't take. TEXT(T1 + L:TL)

         T1 = T1 + L		!Advance to fresh grist.
  13     IF (T1.GT.TL) RETURN	!Perhaps there is no more. No compound testing, alas.
         IF (TEXT(T1:T1).LE." ") THEN	!Does a space follow a line split?
           T1 = T1 + 1		!Yes. It would appear as a leading space in the output.
           GO TO 13          	!But the line split stands in for all that.
         END IF		!So, speed past all such.
         IF (T1.LE.TL) GO TO 10!Does anything remain?
         RETURN		!Nope.
        CONTAINS	!A convenience.
         SUBROUTINE FLUSH	!Save on repetition.
           IF (BL.GT.0) WRITE (OUTBUMF,"(A)") BUMF(1:BL)	!Roll the bumf, if any.
           BL = 0		!And be ready for more.
         END SUBROUTINE FLUSH	!Thus avoid the verbosity of repeated begin ... end blocks.
       END SUBROUTINE FLOW	!Invoke with one large blob, or, pieces.
     END MODULE RIVERRUN	!Flush the tail end with a null text.
     PROGRAM TEST
     USE RIVERRUN
     INTEGER MSG,IN
     CHARACTER*222 BUMF
     MSG = 6
     IN = 10
     CALL STARTFLOW(MSG,36)
     CALL FLOW("Fifteen men on a dead man's chest!")
     CALL FLOW(" Yo ho ho and a bottle of rum!")
     CALL FLOW("Drink and the devil have done for the rest!")
     CALL FLOW(" Yo ho ho and a bottle of rum!")
     CALL FLOW("")
     WRITE (MSG,*)

Chew into my source file for a second example.

     OPEN (IN,FILE="TextFlow.for",ACTION = "READ")
   1 READ (IN,2) BUMF
   2 FORMAT (A)
     IF (BUMF(1:1).NE."C") GO TO 1	!No comment block yet.
     CALL STARTFLOW(MSG,66)		!Found it!
   3 CALL FLOW(BUMF)			!Roll its text.
     READ (IN,2) BUMF			!Grab another line.
     IF (BUMF(1:1).EQ."C") GO TO 3	!And if a comment, append.
     CALL FLOW("")
     CLOSE (IN)
     END</lang>

Output: note that the chorus is presented with a leading space so as to force a new line start for it.

Fifteen men on a dead man's chest!
 Yo ho ho and a bottle of rum! Drink
and the devil have done for the
rest!
 Yo ho ho and a bottle of rum!

Concocted yet again by R.N.McLean (whom God preserve) December MM.
Code checking reveals that the Compaq compiler generates a copy of
the string and then finds the length of that when using the
latter-day intrinsic LEN_TRIM. Madness! Can't   DO WHILE (L.GT.0
.AND. TEXT(L:L).LE.' ') !Control chars. regarded as spaces. Curse
the morons who think it good that the compiler MIGHT evaluate
logical expressions fully. Crude GO TO rather than a DO-loop,
because compilers use a loop counter as well as updating the index
variable. Comparison runs of GNASH showed a saving of ~3% in its
mass-data reading through the avoidance of DO in LSTNB alone.
Crappy code for character comparison of varying lengths is avoided
by using ICHAR which is for single characters only. Checking the
indexing of CHARACTER variables for bounds evoked astounding
stupidities, such as calculating the length of TEXT(L:L) by
subtracting L from L! Comparison runs of GNASH showed a saving of
~25-30% in its mass data scanning for this, involving all its
two-dozen or so single-character comparisons, not just in LSTNB.

For text flowing purposes the actual source lister expected to find block comments with a space after the C (so that column three was the first character of the text to be flowed), so the above source would be listed as-is - except for overprinting key words and underlining, easy with a lineprinter but much more difficult on modern printers that expect a markup language instead.

Go

Basic task, no extra credit. <lang go>package main

import (

   "fmt"
   "strings"

)

func wrap(text string, lineWidth int) (wrapped string) {

   words := strings.Fields(text)
   if len(words) == 0 {
       return
   }
   wrapped = words[0]
   spaceLeft := lineWidth - len(wrapped)
   for _, word := range words[1:] {
       if len(word)+1 > spaceLeft {
           wrapped += "\n" + word
           spaceLeft = lineWidth - len(word)
       } else {
           wrapped += " " + word
           spaceLeft -= 1 + len(word)
       }
   }
   return

}

var frog = ` In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.`

func main() {

   fmt.Println("wrapped at 80:")
   fmt.Println(wrap(frog, 80))
   fmt.Println("wrapped at 72:")
   fmt.Println(wrap(frog, 72))

}</lang>

Output:
wrapped at 80:
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face. Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.
wrapped at 72:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face. Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.

Groovy

Solution 1: Imperative Style <lang groovy>def wordWrap(text, length = 80) {

   def sb = new StringBuilder()
   def line = 
   text.split(/\s/).each { word ->
       if (line.size() + word.size() > length) {
           sb.append(line.trim()).append('\n')
           line = 
       }
       line += " $word"
   }
   sb.append(line.trim()).toString()

}</lang> Testing: <lang groovy>def text = """\

   In olden times when wishing still helped one, there lived a king
   whose daughters were all beautiful, but the youngest was so beautiful
   that the sun itself, which has seen so much, was astonished whenever
   it shone in her face.  Close by the king's castle lay a great dark
   forest, and under an old lime tree in the forest was a well, and when
   the day was very warm, the king's child went out into the forest and
   sat down by the side of the cool fountain, and when she was bored she
   took a golden ball, and threw it up on high and caught it, and this
   ball was her favorite plaything.""".stripIndent().split('\n').join(' ')

println wordWrap(text) println wordWrap(text, 120)</lang>

Output:
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face.  Close by the
king's castle lay a great dark forest, and under an old lime tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.
In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest
was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face.  Close by
the king's castle lay a great dark forest, and under an old lime tree in the forest was a well, and when the day was
very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was
bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.

Solution 2: Using Inject - Functional Style

A solution using the groovy list.inject method which corresponds to foldLeft in other languages.

<lang groovy> String wordWrap(str, width=80) {

 str.tokenize(' ').inject([[]]) { rows, word ->
   if (rows.last().join(' ').length() + word.length() <= width) rows.last() << word else rows << [word]
   rows
 }.collect { it.join(' ') }.join('\n')

} </lang>

this solution shows off the more functional aspects of groovy.

Solution 3: Ninja Style - @TailRecursive and performant

For very large strings (say Shakespeare's complete works which comes in around 7MB in text), the two above solutions are not very performant as they copy large portions of the input string multiple times.

Throwing away all readability, using a number of groovy tricks (abusing default parameter values etc) and just going for performance and terseness of code we get the following:

<lang groovy> import groovy.transform.TailRecursive import static java.lang.Math.min

@TailRecursive String wordWrap(str, w, i=w, b=<<, len=str.length()-1, x=0) {

 b.setCharAt(x = (b << str[b.length()..i]).lastIndexOf(' '), '\n' as char)
 b.length()+w >= len ? b << str[i..-1] : wordWrap(str, w, min(x+w+1, len), b, len, 0)

} </lang>

Should be noted that this is not idiomatic groovy or a recommended way of programming, but it is interesting as an exercise.

Assuming width of 80, we essentially jump 80 characters forward in the text, look backwards for the first space we find, replace that space with a newline, jump forwards 80 characters from the newly inserted newline, look backwards for a space etc.

This means we never look at every character in the input text and we just replace spaces with newlines as we go.

Note that this solution uses recursion and the @TailRecursive annotation which expands the recursive calls into a non-recursive loop at runtime, thus avoiding stack overflow exceptions for large data sets. Note also that the following expressions are equivalent:

<lang groovy> def a = new StringBuilder() def a = << </lang>

Should also be noted that this solution ignores and breaks for the case where words are longer than a line. I have a version which takes this case into account but I figured this was unreadable enough.

Testing can be done as above with the exception that the second wrap width parameter is required.

As an anecdotal baseline for a performance comparison, running 7MB of English text (Shakespeare) through the first algorithm 10 times takes around 3100ms on my current workstation (with a number of warm-up iterations excluded) and running the last algorithm through the same exercise takes around 230ms.

Haskell

Greedy wrapping: <lang haskell>ss =

 concat
   [ "In olden times when wishing still helped one, there lived a king"
   , "whose daughters were all beautiful, but the youngest was so beautiful"
   , "that the sun itself, which has seen so much, was astonished whenever"
   , "it shone in her face.  Close by the king's castle lay a great dark"
   , "forest, and under an old lime-tree in the forest was a well, and when"
   , "the day was very warm, the king's child went out into the forest and"
   , "sat down by the side of the cool fountain, and when she was bored she"
   , "took a golden ball, and threw it up on high and caught it, and this"
   , "ball was her favorite plaything."
   ]

wordwrap maxlen = wrap_ 0 . words

 where
   wrap_ _ [] = "\n"
   wrap_ pos (w:ws)
             -- at line start: put down the word no matter what
     | pos == 0 = w ++ wrap_ (pos + lw) ws
     | pos + lw + 1 > maxlen = '\n' : wrap_ 0 (w : ws)
     | otherwise = ' ' : w ++ wrap_ (pos + lw + 1) ws
     where
       lw = length w

main = mapM_ putStr [wordwrap 72 ss, "\n", wordwrap 32 ss]</lang>


Alternative greedy wrapping: <lang haskell>import Data.List (inits, tails, tail)

testString =

 concat
   [ "In olden times when wishing still helped one, there lived a king"
   , " whose daughters were all beautiful, but the youngest was so beautiful"
   , " that the sun itself, which has seen so much, was astonished whenever"
   , " it shone in her face.  Close by the king's castle lay a great dark"
   , " forest, and under an old lime-tree in the forest was a well, and when"
   , " the day was very warm, the king's child went out into the forest and"
   , " sat down by the side of the cool fountain, and when she was bored she"
   , " took a golden ball, and threw it up on high and caught it, and this"
   , " ball was her favorite plaything."
   ]

wWrap _ [] = [] wWrap i ss =

 (\(a, b) -> a : wWrap i b) $
 last . filter ((<= i) . length . unwords . fst) $ zip (inits ss) (tails ss)

wWrap :: Int -> String -> String wWrap i = unlines . map unwords . wWrap i . words . concat . lines

main = putStrLn $ wWrap 80 testString</lang>

Icon and Unicon

The following works in both languages.

<lang unicon> procedure main(A)

   ll := integer(A[1]) | 72
   wordWrap(&input, ll)

end

procedure wordWrap(f, ll)

   every (sep := "", s := "", w := words(f)) do
      if w == "\n" then write(1(.s, s := sep := ""),"\n")
      else if (*s + *w) >= ll then write(1(.s, s := w, sep := " "))
                              else (s ||:= .sep||("\n" ~== w), sep := " ")
   if *s > 0 then write(s)

end

procedure words(f)

   static wc
   initial wc := &cset -- ' \t'   # Loose definition of a 'word'...
   while l := !f do {
       l ? while tab(upto(wc)) do suspend tab(many(wc))\1
       if *trim(l) = 0 then suspend "\n"   # Paragraph boundary
       }

end</lang>

Sample runs:

->ww <ww.icn
procedure main(A) ll := integer(A[1]) | 72 wordWrap(&input, ll) end

procedure wordWrap(f, ll) every (sep := "", s := "", w := words(f)) do
if w == "\n" then write(1(.s, s := sep := ""),"\n") else if (*s + *w) >=
ll then write(1(.s, s := w, sep := " ")) else (s ||:= .sep||("\n" ~==
w), sep := " ") if *s > 0 then write(s) end

procedure words(f) static wc initial wc := &cset -- ' \t' # Loose
definition of a 'word'... while l := !f do { l ? while tab(upto(wc)) do
suspend tab(many(wc))\1 if *trim(l) = 0 then suspend "\n" # Paragraph
boundary } end
->ww 50 <ww.icn
procedure main(A) ll := integer(A[1]) | 72
wordWrap(&input, ll) end

procedure wordWrap(f, ll) every (sep := "", s :=
"", w := words(f)) do if w == "\n" then
write(1(.s, s := sep := ""),"\n") else if (*s +
*w) >= ll then write(1(.s, s := w, sep := " "))
else (s ||:= .sep||("\n" ~== w), sep := " ") if *s
> 0 then write(s) end

procedure words(f) static wc initial wc := &cset
-- ' \t' # Loose definition of a 'word'... while l
:= !f do { l ? while tab(upto(wc)) do suspend
tab(many(wc))\1 if *trim(l) = 0 then suspend "\n"
# Paragraph boundary } end
->

IS-BASIC

The word warp, any kind of text alignment, specifying tab positions are basic services of the EXOS operating system. <lang IS-BASIC>100 TEXT 80 110 CALL WRITE(12,68,0) 120 PRINT :CALL WRITE(10,70,1) 130 DEF WRITE(LEFTMARGIN,RIGHTMARGIN,JUSTIFIED) 140 STRING S$*254 150 RESTORE 160 PRINT TAB(LEFTMARGIN);CHR$(243); 170 PRINT TAB(RIGHTMARGIN-1);CHR$(251) 180 DO 190 READ IF MISSING EXIT DO:S$ 200 PRINT S$; 210 LOOP 220 IF JUSTIFIED THEN PRINT CHR$(248) ! <- Extra credit :-) 230 PRINT 240 END DEF 250 DATA "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. " 260 DATA "Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, " 270 DATA "and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything." </lang>

Output:
           In olden times when wishing still helped one, there                  
           lived a king whose daughters were all beautiful, but the             
           youngest was so beautiful that the sun itself, which has             
           seen so much, was astonished whenever it shone in her                
           face. Close by the king's castle lay a great dark                    
           forest, and under an old lime-tree in the forest was a               
           well, and when the day was very warm, the king's child               
           went out into the forest and sat down by the side of the             
           cool fountain, and when she was bored she took a golden              
           ball, and threw it up on high and caught it, and this                
           ball was her favorite plaything.

         In  olden times when wishing still helped one, there lived a          
         king  whose  daughters  were all beautiful, but the youngest          
         was  so  beautiful  that  the sun  itself, which has seen so          
         much, was astonished whenever it shone in her face. Close by          
         the  king's castle lay a great dark forest, and under an old          
         lime-tree  in  the  forest  was a well, and when the day was          
         very warm, the king's child went out into the forest and sat          
         down  by  the  side  of  the cool fountain, and when she was          
         bored  she  took  a golden ball, and threw it up on high and          
         caught it, and this ball was her favorite plaything.

J

Solution:<lang j>ww =: 75&$: : wrap

 wrap    =: (] turn edges) ,&' '
   turn  =:  LF"_`]`[}
   edges =: (_1 + ] #~ 1 ,~ 2 >/\ |) [: +/\ #;.2</lang>

Example:<lang j> GA =: 'Four score and seven years ago, our forefathers brought forth upon this continent a new nation, dedicated to the proposition that all men were created equal.'

  ww GA  NB.  Wrap at 75 chars by default

Four score and seven years ago, our forefathers brought forth upon this continent a new nation, dedicated to the proposition that all men were created equal.

  20 ww GA  NB.  Specify different length

Four score and seven years ago, our forefathers brought forth upon this continent a new nation, dedicated to the proposition that all men were created equal.</lang>

Java

<lang java> package rosettacode;

import java.util.StringTokenizer;

public class WordWrap { int defaultLineWidth=80; int defaultSpaceWidth=1; void minNumLinesWrap(String text) { minNumLinesWrap(text,defaultLineWidth); } void minNumLinesWrap(String text,int LineWidth) { StringTokenizer st=new StringTokenizer(text); int SpaceLeft=LineWidth; int SpaceWidth=defaultSpaceWidth; while(st.hasMoreTokens()) { String word=st.nextToken(); if((word.length()+SpaceWidth)>SpaceLeft) { System.out.print("\n"+word+" "); SpaceLeft=LineWidth-word.length(); } else { System.out.print(word+" "); SpaceLeft-=(word.length()+SpaceWidth); } } } public static void main(String[] args) { WordWrap now=new WordWrap(); String wodehouse="Old Mr MacFarland (_said Henry_) started the place fifteen years ago. He was a widower with one son and what you might call half a daughter. That's to say, he had adopted her. Katie was her name, and she was the child of a dead friend of his. The son's name was Andy. A little freckled nipper he was when I first knew him--one of those silent kids that don't say much and have as much obstinacy in them as if they were mules. Many's the time, in them days, I've clumped him on the head and told him to do something; and he didn't run yelling to his pa, same as most kids would have done, but just said nothing and went on not doing whatever it was I had told him to do. That was the sort of disposition Andy had, and it grew on him. Why, when he came back from Oxford College the time the old man sent for him--what I'm going to tell you about soon--he had a jaw on him like the ram of a battleship. Katie was the kid for my money. I liked Katie. We all liked Katie."; System.out.println("DEFAULT:"); now.minNumLinesWrap(wodehouse); System.out.println("\n\nLINEWIDTH=120"); now.minNumLinesWrap(wodehouse,120); }

}

</lang>

JavaScript

Recursive

Solution:<lang javascript> function wrap (text, limit) {

 if (text.length > limit) {
   // find the last space within limit
   var edge = text.slice(0, limit).lastIndexOf(' ');
   if (edge > 0) {
     var line = text.slice(0, edge);
     var remainder = text.slice(edge + 1);
     return line + '\n' + wrap(remainder, limit);
   }
 }
 return text;

} </lang> Example:<lang javascript> console.log(wrap(text, 80)); </lang>

Output:
Wrap text using a more sophisticated algorithm such as the Knuth and Plass TeX
algorithm. If your language provides this, you get easy extra credit, but you
must reference documentation indicating that the algorithm is something better
than a simple minimimum length algorithm.

Example:<lang javascript> console.log(wrap(text, 42)); </lang>

Output:
Wrap text using a more sophisticated
algorithm such as the Knuth and Plass TeX
algorithm. If your language provides
this, you get easy extra credit, but you
must reference documentation indicating
that the algorithm is something better
than a simple minimimum length algorithm.

Simple regex

A simple regex suffices (and proves fastest) for the greedy version:

<lang javascript>(function (width) {

   'use strict';
   function wrapByRegex(n, s) {
       return s.match(
               RegExp('.{1,' + n + '}(\\s|$)', 'g')
           )
           .join('\n');
   }
   return wrapByRegex(width,

'Even today, with proportional fonts and compl\ ex layouts, there are still cases where you ne\ ed to wrap text at a specified column. The bas\ ic task is to wrap a paragraph of text in a si\ mple way in your language. If there is a way t\ o do this that is built-in, trivial, or provid\ ed in a standard library, show that. Otherwise\

implement the minimum length greedy algorithm\
from Wikipedia.'
   )

})(60);</lang>

Output:
Even today, with proportional fonts and complex layouts, 
there are still cases where you need to wrap text at a 
specified column. The basic task is to wrap a paragraph of 
text in a simple way in your language. If there is a way to 
do this that is built-in, trivial, or provided in a standard 
library, show that. Otherwise implement the minimum length 
greedy algorithm from Wikipedia.

EcmaScript 6

<lang javascript> /**

* [wordwrap description]
* @param  {[type]}  text  [description]
* @param  {Number}  width [description]
* @param  {String}  br    [description]
* @param  {Boolean} cut   [description]
* @return {[type]}        [description]
*/

function wordwrap(text, width = 80, br = '\n', cut = false) {

 // Приводим к uint
 // 0..2^32-1 либо 0..2^64-1 
 width >>>= 0;
 // Длина текста меньше или равна максимальной
 if (0 === width || text.length <= width) {
   return text;
 }
 // Разбиваем текст на строки
 return text.split('\n').map(line => {
   if (line.length <= width) {
     return line;
   }
   // Разбиваем строку на слова
   let words = line.split(' ');
   // Если требуется, то обрезаем длинные слова
   if (cut) {
     let temp = [];
     for (const word of words) {
       if (word.length > width) {
         let i = 0;
         const length = word.length;
         while (i < length) {
           temp.push(word.slice(i, Math.min(i + width, length)));
           i += width;
         }
       } else {
         temp.push(word);
       }
     }
     words = temp;
   }
   // console.log(words);
   // Собираем новую строку
   let wrapped = words.shift();
   let spaceLeft = width - wrapped.length;
   for (const word of words) {
     if (word.length + 1 > spaceLeft) {
       wrapped += br + word;
       spaceLeft = width - word.length;
     } else {
       wrapped += ' ' + word;
       spaceLeft -= 1 + word.length;
     }
   }
   return wrapped;
 }).join('\n'); // Объединяем элементы массива по LF

} </lang>

Example<lang javascript> console.log(wordwrap("The quick brown fox jumped over the lazy dog.", 20, "
\n")); </lang>

Output:
The quick brown fox<br />
jumped over the lazy<br />
dog.

jq

Works with: jq version >1.4

The following implementation requires a version of jq with splits/1, for splitting on whitespace.

In jq, all strings are Unicode strings, for which the length is calculated as the number of codepoints. <lang jq># Simple greedy algorithm.

  1. Note: very long words are not truncated.
  2. input: a string
  3. output: an array of strings

def wrap_text(width):

 reduce splits("\\s+") as $word
   ([""];
    .[length-1] as $current
    | ($word|length) as $wl
    | (if $current == "" then 0 else 1 end) as $pad
    | if $wl + $pad + ($current|length) <= width
      then .[-1] += ($pad * " ") + $word
      else . + [ $word]
      end );</lang>

Task 1: <lang jq>"aaa bb cc ddddd" | wrap_text(6)[] # wikipedia example</lang>

Output:
aaa bb
cc
ddddd

Task 2: <lang jq>"aaa bb cc ddddd" | wrap_text(5)[]</lang>

Output:
aaa
bb cc
ddddd

With input from a file: Russian.txt

<lang sh>советских военных судов и самолетов была отмечена в Японском море после появления там двух американских авианосцев. Не менее 100 советских самолетов поднялись в воздух, когдаамериканские авианосцы "Уинсон" и "Мидуэй" приблизились на 50 миль к Владивостоку.

</lang>

Main:

wrap_text(40)[]
Output:

<lang sh>$ jq -M -R -s -r -f Word_wrap.jq Russian.txt советских военных судов и самолетов была отмечена в Японском море после появления там двух американских авианосцев. Не менее 100 советских самолетов поднялись в воздух, когдаамериканские авианосцы "Уинсон" и "Мидуэй" приблизились на 50 миль к Владивостоку. </lang>

Julia

Works with: Julia version 0.6

Using TextWrap.jl library.

<lang julia>using TextWrap

text = """Reformat the single paragraph in 'text' to fit in lines of no more

   than 'width' columns, and return a new string containing the entire
   wrapped paragraph.  As with wrap(), tabs are expanded and other
   whitespace characters converted to space.  See TextWrapper class for
   available keyword args to customize wrapping behaviour."""

println("# Wrapped at 80 chars") print_wrapped(text, width=80) println("\n\n# Wrapped at 70 chars") print_wrapped(text, width=70)</lang>

Output:
# Wrapped at 80 chars
Reformat the single paragraph in 'text' to fit in lines of no more than 'width'
columns, and return a new string containing the entire wrapped paragraph.  As
with wrap(), tabs are expanded and other whitespace characters converted to
space.  See TextWrapper class for available keyword args to customize wrapping
behaviour.

# Wrapped at 70 chars
Reformat the single paragraph in 'text' to fit in lines of no more
than 'width' columns, and return a new string containing the entire
wrapped paragraph.  As with wrap(), tabs are expanded and other
whitespace characters converted to space.  See TextWrapper class for
available keyword args to customize wrapping behaviour.

Kotlin

<lang scala>// version 1.1.3

val text =

   "In olden times when wishing still helped one, there lived a king " +
   "whose daughters were all beautiful, but the youngest was so beautiful " +
   "that the sun itself, which has seen so much, was astonished whenever " +
   "it shone in her face.  Close by the king's castle lay a great dark " +
   "forest, and under an old lime tree in the forest was a well, and when " +
   "the day was very warm, the king's child went out into the forest and " +
   "sat down by the side of the cool fountain, and when she was bored she " +
   "took a golden ball, and threw it up on high and caught it, and this " +
   "ball was her favorite plaything."

fun greedyWordwrap(text: String, lineWidth: Int): String {

   val words = text.split(' ') 
   val sb = StringBuilder(words[0]) 
   var spaceLeft = lineWidth - words[0].length
   for (word in words.drop(1)) {
       val len = word.length
       if (len + 1 > spaceLeft) {
           sb.append("\n").append(word)            
           spaceLeft = lineWidth - len
       }
       else {
           sb.append(" ").append(word)
           spaceLeft -= (len + 1)
       }
   }
   return sb.toString()

}

fun main(args: Array<String>) {

   println("Greedy algorithm - wrapped at 72:")
   println(greedyWordwrap(text, 72))
   println("\nGreedy algorithm - wrapped at 80:")
   println(greedyWordwrap(text, 80))

}</lang>

Output:
Greedy algorithm - wrapped at 72:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face.  Close by the king's castle lay a great dark forest, and under
an old lime tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.

Greedy algorithm - wrapped at 80:
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face.  Close by the
king's castle lay a great dark forest, and under an old lime tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.

Lambdatalk

The test text will be the third first paragraphs of Jules Verne's book, The Mysterious Island. <lang scheme> {def text Personne n’a sans doute oublié le terrible coup de vent de nord-est qui se déchaîna au milieu de l’équinoxe de cette année, et pendant lequel le baromètre tomba à sept cent dix millimètres. Ce fut un ouragan, sans intermittence, qui dura du 18 au 26 mars. Les ravages qu’il produisit furent immenses en Amérique, en Europe, en Asie, sur une zone large de dix-huit cents milles, qui se dessinait obliquement à l’équateur, depuis le trente-cinquième parallèle nord jusqu’au quarantième parallèle sud ! (L’île mystérieuse / Jules Verne)} -> text </lang>

1) lambdatalk can simply call HTML tags and CSS rules: <lang scheme> {def wrap1

{lambda {:n}
 pre {@ style="width::npx;                   // the line width
               white-space:pre-wrap; "}}}    // the word-wrap rule

-> wrap1

{{wrap1 380} {text}} -> Personne n’a sans doute oublié le terrible coup de vent de nord-est qui se déchaîna au milieu de l’équinoxe de cette année, et pendant lequel le baromètre tomba à sept cent dix millimètres. Ce fut un ouragan, sans intermittence, qui dura du 18 au 26 mars. Les ravages qu’il produisit furent immenses en Amérique, en Europe, en Asie, sur une zone large de dix-huit cents milles, qui se dessinait obliquement à l’équateur, depuis le trente-cinquième parallèle nord jusqu’au quarantième parallèle sud ! (L’île mystérieuse / Jules Verne) </lang>

2) a lambdatalk function

A translation from the Kotlin entry: <lang scheme> {def wrap2

{def wrap2.r
 {lambda {:linewidth :arr :spaceleft :sb}
  {if {A.empty? :arr}
   then {S.rest :sb}
   else {let { {:linewidth :linewidth}
               {:arr :arr}
               {:spaceleft :spaceleft} 
               {:word {A.first :arr}}
               {:length {W.length {A.first :arr}}}
               {:sb :sb} 
             } {wrap2.r :linewidth 
                        {A.rest :arr} 
                        {if {> {+ :length 1} :spaceleft}
                         then {- :linewidth :length} :sb{br}:word
                         else {- :spaceleft {+ :length 1}} :sb :word} }}}}}
{lambda {:linewidth :text}
 {wrap2.r :linewidth 
          {A.new :text}
          {- :linewidth {W.length {S.get 0 :text}}} 
          #}}}

-> wrap2

{wrap2 70 {text}} -> Personne n’a sans doute oublié le terrible coup de vent de nord-est qui se déchaîna au milieu de l’équinoxe de cette année, et pendant lequel le baromètre tomba à sept cent dix millimètres. Ce fut un ouragan, sans intermittence, qui dura du 18 au 26 mars. Les ravages qu’il produisit furent immenses en Amérique, en Europe, en Asie, sur une zone large de dix-huit cents milles, qui se dessinait obliquement à l’équateur, depuis le trente-cinquième parallèle nord jusqu’au quarantième parallèle sud ! (L’île mystérieuse / Jules Verne) </lang>

3) A translation of the javascript entry. The {jswrap n text} function contains lines until n characters

<lang javascript> LAMBDATALK.DICT['jswrap'] = function() {

 var wrap = function(text, limit) {
   if (text.length > limit) {
     var edge = text.slice(0, limit).lastIndexOf(' ');
     if (edge > 0) {
       var line = text.slice(0, edge);
       var remainder = text.slice(edge + 1);
       return line + '\n' + wrap(remainder, limit);
     }
   }
   return text;
 };
 var args = arguments[0].trim().split(" ");
 var limit = parseInt(args.shift());
 var text = args.join(" ");
 return wrap(text,limit);

};

{jswrap 60 {text}} -> Personne n’a sans doute oublié le terrible coup de vent de nord-est qui se déchaîna au milieu de l’équinoxe de cette année, et pendant lequel le baromètre tomba à sept cent dix millimètres. Ce fut un ouragan, sans intermittence, qui dura du 18 au 26 mars. Les ravages qu’il produisit furent immenses en Amérique, en Europe, en Asie, sur une zone large de dix-huit cents milles, qui se dessinait obliquement à l’équateur, depuis le trente-cinquième parallèle nord jusqu’au quarantième parallèle sud ! (L’île mystérieuse / Jules Verne) </lang>

Lasso

<lang Lasso>define wordwrap( text::string, row_length::integer = 75 ) => { return regexp(`(?is)(.{1,` + #row_length + `})(?:$|\W)+`, '$1
\n', #text, true) -> replaceall }

local(text = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris consequat ornare lectus, dignissim iaculis libero consequat sed. Proin quis magna in arcu sagittis consequat sed ac risus. Ut a pharetra dui. Phasellus molestie, mauris eget scelerisque laoreet, diam dolor vulputate nulla, in porta sem sem sit amet lacus.')

wordwrap(#text, 40)

'


'

wordwrap(#text)

'


'

wordwrap(#text, 90)</lang>

->

Lorem ipsum dolor sit amet, consectetur
adipiscing elit. Mauris consequat ornare
lectus, dignissim iaculis libero
consequat sed. Proin quis magna in arcu
sagittis consequat sed ac risus. Ut a
pharetra dui. Phasellus molestie, mauris
eget scelerisque laoreet, diam dolor
vulputate nulla, in porta sem sem sit
amet lacus.
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris consequat
ornare lectus, dignissim iaculis libero consequat sed. Proin quis magna in
arcu sagittis consequat sed ac risus. Ut a pharetra dui. Phasellus molestie
mauris eget scelerisque laoreet, diam dolor vulputate nulla, in porta sem
sem sit amet lacus.
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris consequat ornare lectus,
dignissim iaculis libero consequat sed. Proin quis magna in arcu sagittis consequat sed ac
risus. Ut a pharetra dui. Phasellus molestie, mauris eget scelerisque laoreet, diam dolor
vulputate nulla, in porta sem sem sit amet lacus.

LFE

Naive Implementation

Translation of: Erlang

<lang Lisp> (defun wrap-text (text)

 (wrap-text text 78))

(defun wrap-text (text max-len)

 (string:join
   (make-wrapped-lines
     (string:tokens text " ") max-len)
   "\n"))

(defun make-wrapped-lines

 (((cons word rest) max-len)
   (let ((`#(,_ ,_ ,last-line ,lines) (assemble-lines max-len word rest)))
     (lists:reverse (cons last-line lines)))))

(defun assemble-lines (max-len word rest)

 (lists:foldl
   #'assemble-line/2
   `#(,max-len ,(length word) ,word ())
   rest))

(defun assemble-line

 ((word `#(,max ,line-len ,line ,acc)) (when (> (+ (length word) line-len) max))
   `#(,max ,(length word) ,word ,(cons line acc)))
 ((word `#(,max ,line-len ,line ,acc))
   `#(,max ,(+ line-len 1 (length word)) ,(++ line " " word) ,acc)))

</lang>

Regex Implementation

<lang lisp> (defun make-regex-str (max-len)

 (++ "(.{1," (integer_to_list max-len) "}|\\S{"
     (integer_to_list (+ max-len 1)) ",})(?:\\s[^\\S\\r\\n]*|\\Z)"))

(defun wrap-text (text max-len)

 (let ((find-patt (make-regex-str max-len))
       (replace-patt "\\1\\\n"))
   (re:replace text find-patt replace-patt
               '(global #(return list)))))

</lang>

Usage examples:

<lang Lisp> > (set test-text (++ "Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column. "

                    "The basic task is to wrap a paragraph of text in a simple way in your language. If there is a way to do this that is built-in, trivial, or "
                    "provided in a standard library, show that. Otherwise implement the minimum length greedy algorithm from Wikipedia.")

> (io:format (wrap-text text 80)) </lang>

Even today, with proportional fonts and complex layouts, there are still cases
where you need to wrap text at a specified column. The basic task is to wrap a
paragraph of text in a simple way in your language. If there is a way to do this
that is built-in, trivial, or provided in a standard library, show that.
Otherwise implement the minimum length greedy algorithm from Wikipedia.
ok

<lang lisp> > (io:format (wrap-text text 50)) </lang>

Even today, with proportional fonts and complex
layouts, there are still cases where you need to
wrap text at a specified column. The basic task is
to wrap a paragraph of text in a simple way in
your language. If there is a way to do this that
is built-in, trivial, or provided in a standard
library, show that. Otherwise implement the
minimum length greedy algorithm from Wikipedia.
ok

Lingo

Lingo/Director has 2 visual components for displaying text, text and field members. Both can soft-wrap text directly. In cases where you need a hard-wrapped representation of a text, this could e.g. be implemented like this: (Note: this solution is meant for proportional fonts and based on actual text rendering. For the more trivial case of non-proportial font word wrapping, just pass a non-proportinal font like e.g. Courier in the 'style' argument) <lang lingo>-- in some movie script


-- Wraps specified text into lines of specified width (in px), returns lines as list of strings -- @param {string} str -- @param {integer} pixelWidth -- @param {propList} [style] -- @return {list}


on hardWrapText (str, pixelWidth, style)

 if voidP(style) then style = [:]
 lines = []
 -- create a new field member
 m = new(#field)
 m.text = str
 m.rect = rect(0,0,pixelWidth,0)
 -- assign style props (if not specified, defaults are used)
 repeat with i = 1 to style.count
   m.setProp(style.getPropAt(i), style[i])
 end repeat
 -- create an invisible temporary sprite
 s = channel(1).makeScriptedSprite(m)
 s.loc = point(0,0)
 s.visible = false
 _movie.updateStage()
 
 -- get the wrapped lines
 charPos = 0
 repeat with y = 0 to s.height-1
   n = s.pointToChar(point(pixelWidth-1, y))
   if n<>charPos then
     lines.add(str.char[charPos+1..n])
     charPos = n
   end if
 end repeat
 
 channel(1).removeScriptedSprite()
 return lines

end</lang> Usage: <lang lingo>str = "Lorem ipsum dolor sit amet, consectetur adipisici elit, sed "&\ "eiusmod tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim "&\ "veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi "&\ "consequat. Quis aute iure reprehenderit in voluptate velit esse cillum dolore eu "&\ "fugiat nulla pariatur. Excepteur sint obcaecat cupiditat non proident, sunt in "&\ "culpa qui officia deserunt mollit anim id est laborum."

lines = hardWrapText(str, 320, [#font: "Arial", #fontSize:24])

repeat with l in lines

 put l

end repeat</lang>

Output:
-- "Lorem ipsum dolor sit amet, "
-- "consectetur adipisici elit, sed "
-- "eiusmod tempor incidunt ut "
-- "labore et dolore magna "
-- "aliqua. Ut enim ad minim "
-- "veniam, quis nostrud "
-- "exercitation ullamco laboris "
-- "nisi ut aliquid ex ea commodi "
-- "consequat. Quis aute iure "
-- "reprehenderit in voluptate "
-- "velit esse cillum dolore eu "
-- "fugiat nulla pariatur. "
-- "Excepteur sint obcaecat "
-- "cupiditat non proident, sunt "
-- "in culpa qui officia deserunt "
-- "mollit anim id est laborum."

Lua

<lang lua>function splittokens(s)

   local res = {}
   for w in s:gmatch("%S+") do
       res[#res+1] = w
   end
   return res

end

function textwrap(text, linewidth)

   if not linewidth then
       linewidth = 75
   end
   local spaceleft = linewidth
   local res = {}
   local line = {}
   for _, word in ipairs(splittokens(text)) do
       if #word + 1 > spaceleft then
           table.insert(res, table.concat(line, ' '))
           line = {word}
           spaceleft = linewidth - #word
       else
           table.insert(line, word)
           spaceleft = spaceleft - (#word + 1)
       end
   end
   table.insert(res, table.concat(line, ' '))
   return table.concat(res, '\n')

end

local example1 = [[ Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column. The basic task is to wrap a paragraph of text in a simple way in your language. If there is a way to do this that is built-in, trivial, or provided in a standard library, show that. Otherwise implement the minimum length greedy algorithm from Wikipedia. ]]

print(textwrap(example1)) print() print(textwrap(example1, 60))</lang>

Output:
Even today, with proportional fonts and complex layouts, there are still
cases where you need to wrap text at a specified column. The basic task is
to wrap a paragraph of text in a simple way in your language. If there is a
way to do this that is built-in, trivial, or provided in a standard
library, show that. Otherwise implement the minimum length greedy algorithm
from Wikipedia.

Even today, with proportional fonts and complex
layouts, there are still cases where you need to wrap
text at a specified column. The basic task is to wrap a
paragraph of text in a simple way in your language. If
there is a way to do this that is built-in, trivial, or
provided in a standard library, show that. Otherwise
implement the minimum length greedy algorithm from
Wikipedia.

M2000 Interpreter

M2000 Environment (where actual a M2000 script executed) provide the means to print proportional text, in console, in layer in console form, in user windows layers, and in printer paper. To render proportional text we can use:

Print statement with styles from 4 to 10 (so 0 to 3 are non proportional, by default we use 0). Styles applied with $() print's internal function. So a Print $(4), set from current position the proportional style. This has word wrap, but stop at wrapping. Print statement not used for documents (or strings with paragraphs). We can print text with diacritics.

Report statement is the default renderer for text. Not only render text, but can be used to calculate the number of lines before actual render text. Report also prints in characters row, and can be used with Double statement to change temporary to Double height font. Also use Italic and Bold state. Also can print text with diacritics as Print statement can. Lead space from paragraph stay there, and spaces can be get bigger or smaller from original size, but not to small. Because we can give the width of the output (in character units, or in twips units), we can find easy the bounding box. Report statement when rendering to anything except console, stop rendering, after scrolling the 3/4 of layer height (the lower part which can scroll, maybe all the height, depends on setting split screen function), waiting for user to press space or a mouse button.

Legend Statement use Font and font size (Mode in M2000) for each call, and print text in graphic position, using alignment but not word warp, and we can use rotation. Functions size.x() and size.y() can return then dimension of the bounding box,

We can use controls on forms to render text, and EditBox has word wrap, and a state when no edit allowed, we can view/scroll text only.

This example use a text in a$, where first remove line breaks. Then set font to Tahoma, and console size to 80 characters by 50 lines, and display the current font size (automatic environment insert line space between text rows). Also display state for Bold and Italic. Then we get the text from 9th row, as proportional text, italic, centered with a width for lines as 60 characters width. Then ask for a keypress.

At the second phase, in a loop, render text twice, the first as is, the second changing color in each line. To perform that, it render once without displaying, get from ReportLines the number of lines, and then execute a for loop and do a partial display, but each time rendering starts from first line, and display from the line we choose, for lines we choose (first choose lines and next using Line choose the first line). Until now we didn't get somewhere in memory the actual lines, only in layer, displayed.

At the third phase, we can get in a document variable all lines (where actual made each line break). We can find the length in twips for each line, but this is with spaces with standard width. Report use spaces smaller or bigger than normal space, and do a distribution of pixels that can't be fit in all spaces chunks, mostly at the right chunks. So even using a non proportional font, we get from Report at rendering proportional spacings.

The inner editor of M2000 environment also works with Word Warp and can change it with F1 any time. Also EditBox can change with F1 word wrap, in user forms (windows).

All of these statements not handle tab character (9) as tab. Editor change tab with spaces, and Print/report/Legend prints tab as a square character (as for 9.4 version of M2000 Environment and Interpreter).

<lang M2000 Interpreter> Module Checkit {

     \\ leading space from begin of paragraph stay as is
     a$={     In olden times when wishing still helped one, there
     lived a king whose daughters were all beautiful, but the youngest
     was so beautiful that the sun itself, which has seen so
     much, was astonished whenever it shone in her face.
     }
     const crlf$=chr$(13)+chr$(10)
     a$=replace$(crlf$, " ", a$)+crlf$
     const justify=0
     const flushright=1
     const centered=2
     const flushleft=3
     \\ set layer font
     Font "Tahoma"
     Form 80, 50
     Print "Font:";Fontname$
     Print "Font size:";Mode;"pt"
     Print "Bold:";Bold
     Print "Italic:";Italic
     \\ set left margin for Report
     Cursor 10, 8 ' pos 10 row 8 (11 9 - it is 0 based)
     m=Italic
     Italic 1
     Report centered, trim$(A$), Width-10-10
     Italic m
     
     Print  @(0,79),"Press any key";
     wait$=key$
     Refresh 5000
     charwidth=scale.x div width
     For i=2000 to scale.x-charwidth step 150
           \\ clear screen with 14pt fonts
          
           Mode 12.75
           \\ by default use justify, word wrap
           Report a$, i
           \\  we can calculate only using a negative parameter
           Report a$, i, -10000
           k=ReportLines 
           \\ print any line in differnet color
           Dim a(2)
           a(0)=11, 15   ' 0 to 15 are vb6 colors, we can use html colors #aabbcc, #ff2211
           For j=1 to k {
               Pen a(j mod 2) {
                       Report a$, i, 1 line j
                 }  
           }
           Refresh 5000
           wait$=key$
     Next i
     
     Report a$, scale.x/2, -1000
     k=ReportLines 
     Document  Doc$
     Report a$, scale.x/2, k as Doc$
     \\ Print document without expanding spaces
     Print $(4), ' 4=proportional printing using columns, on line online, word wrap, expand to fit in columns
     For i=1 to k {
     Print "*";Paragraph$(Doc$, i);"*"
     }
     Print $(0),   ' restore to non proportional printing
     For i=1 to k {
           Print i, size.x(Paragraph$(Doc$, i), Fontname$, Mode), size.y(Paragraph$(Doc$, i), Fontname$, Mode)
     }
     \\ scale.x unit in twips
     Report a$, scale.x/2
     \\ width unit in characters
     Report a$, width/2  
     Print @(width div 2),
     Report flushright, a$, width/2  
     Cursor 0, Row
     I=Italic
     Double
     Italic 1
     Report centered, a$
     Italic I
     Double
     Normal

} Checkit </lang>

Mathematica

<lang Mathematica>string="In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything."; wordWrap[textWidth_,spaceWidth_,string_]:=Module[{start,spaceLeft,masterString},

spaceLeft=textWidth;
start=1;
masterString={};
Do[
 If[i+1>Length@StringSplit@string
  ,
  p=StringSplit[string]start;;i;
  AppendTo[masterString,{StringJoin@@Riffle[p,StringJoin@ConstantArray[" ",spaceWidth]]}]
  ,
  If[StringLength[StringSplit@string]i+1+spaceWidth>spaceLeft
    ,
    spaceLeft=textWidth-StringLength[StringSplit@string]i;
    start=i;
    AppendTo[masterString,{StringJoin@@Riffle[p,StringJoin@ConstantArray[" ",spaceWidth]]}]
    ,
    spaceLeft-=StringLength[StringSplit@string]i;
    spaceLeft-=spaceWidth;
    p=StringSplit[string]start;;i
   ]
  ]
 ,
 {i,1,Length@StringSplit@string}
];
StringJoin@@Riffle[masterString,"\n"]

];</lang>

Output:

for width 72 and 80

<lang>wordWrap[72, 1, string] wordWrap[80, 1, string]</lang>

Output:
In olden times when wishing still helped one, there lived a king
whose daughters were all beautiful, but the youngest was so beautiful
that the sun itself, which has seen so much, was astonished whenever
it shone in her face. Close by the king's castle lay a great dark forest,
and under an old lime-tree in the forest was a well, and when the day
was very warm, the king's child went out into the forest and sat down
by the side of the cool fountain, and when she was bored she took a
golden ball, and threw it up on high and caught it, and this ball was
her favorite plaything.

In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face. Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into
the forest and sat down by the side of the cool fountain, and when she was bored
she took a golden ball, and threw it up on high and caught it, and this ball was
her favorite plaything.

MiniScript

<lang MiniScript>str = "one two three four five six seven eight nine ten eleven!" width = 15 words = str.split pos = 0 line = "" for word in words

   pos = pos + word.len + 1
   if pos <= width then
       line = line + word + " "
   else
       print line[:-1]
       line = word + " "
       pos = word.len
   end if

end for print line[:-1]</lang>

Output:
one two three
four five six
seven eight
nine ten
eleven!

NetRexx

version 1

<lang NetRexx>/* NetRexx */ options replace format comments java crossref symbols

runSample(arg) return

-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /*

  @see http://en.wikipedia.org/wiki/Word_wrap#Minimum_length
  SpaceLeft := LineWidth
  for each Word in Text
      if (Width(Word) + SpaceWidth) > SpaceLeft
          insert line break before Word in Text
          SpaceLeft := LineWidth - Width(Word)
      else
          SpaceLeft := SpaceLeft - (Width(Word) + SpaceWidth)
*/

method wordWrap(text, lineWidth = 80) public static

 if lineWidth > 0 then do
   NL = '\n'
   SP = ' '
   wrapped = 
   spaceWidth = SP.length()
   spaceLeft = lineWidth
   loop w_ = 1 to text.words()
     nextWord = text.word(w_)
     if (nextWord.length() + spaceWidth) > spaceLeft then do
       wrapped = wrapped || NL || nextWord
       spaceLeft = lineWidth - nextWord.length()
       end
     else do
       wrapped = wrapped || SP || nextWord
       spaceLeft = spaceLeft - (nextWord.length() + spaceWidth)
       end
     end w_
   end
 else do
   wrapped = text
   end
 
 return wrapped.strip() -- clean w/s from front & back

-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method runSample(arg) public static

 parse arg lineLen .
 if lineLen  =  then lineLen = 80
 text = getText()
 wrappedLines = wordWrap(text, lineLen)
 say 'Wrapping text at' lineLen 'characters'
 say ('....+....|'.copies((lineLen + 9) % 10)).left(lineLen)
 say wrappedLines
 
 return

-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ method getText() public static

 -- ....+....|....+....|....+....|....+....|....+....|....+....|
 speech01 = -
   'She should have died hereafter;' -
   'There would have been a time for such a word.' -
   'Tomorrow, and tomorrow, and tomorrow,' -
   'Creeps in this petty pace from day to day,' -
   'To the last syllable of recorded time;' -
   'And all our yesterdays have lighted fools' -
   'The way to dusty death. Out, out, brief candle!' -
   'Lifes but a walking shadow, a poor player' -
   'That struts and frets his hour upon the stage' -
   'And then is heard no more. It is a tale' -
   'Told by an idiot, full of sound and fury' -
   'Signifying nothing.' -
    -
   '—-Macbeth (Act 5, Scene 5, lines 17-28)' -
   
 return speech01

</lang>

Output:
Wrapping text at 64 characters
....+....|....+....|....+....|....+....|....+....|....+....|....
She should have died hereafter; There would have been a time
for such a word. Tomorrow, and tomorrow, and tomorrow, Creeps in
this petty pace from day to day, To the last syllable of
recorded time; And all our yesterdays have lighted fools The way
to dusty death. Out, out, brief candle! Life's but a walking
shadow, a poor player That struts and frets his hour upon the
stage And then is heard no more. It is a tale Told by an idiot,
full of sound and fury Signifying nothing. —-Macbeth (Act 5,
Scene 5, lines 17-28)

Wrapping text at 132 characters
....+....|....+....|....+....|....+....|....+....|....+....|....+....|....+....|....+....|....+....|....+....|....+....|....+....|..
She should have died hereafter; There would have been a time for such a word. Tomorrow, and tomorrow, and tomorrow, Creeps in this
petty pace from day to day, To the last syllable of recorded time; And all our yesterdays have lighted fools The way to dusty death.
Out, out, brief candle! Life's but a walking shadow, a poor player That struts and frets his hour upon the stage And then is heard
no more. It is a tale Told by an idiot, full of sound and fury Signifying nothing. —-Macbeth (Act 5, Scene 5, lines 17-28)

version 2

<lang NetRexx>/* NetRexx ************************************************************

  • 23.08.2013 Walter Pachl translated from REXX version 2
                                                                                                                                            • /

options replace format comments java crossref symbols

runSample(arg)

method runSample(arg) public static

 s='She should have died hereafter;' -
 'There would have been a time for such a word.' -
 'Tomorrow, and tomorrow, and tomorrow, and so on'
 w=72
 Say s.length
 loop while s>' '
   Loop i=w+1 to 1 by -1
     If s.substr(i,1)= Then
       Leave
     End
   If i=0 Then
     p=s.pos(' ')
   Else
     p=i
   say s.left(p)
   s=s.substr(p+1)
   End
 If s> Then
   say s
 return</lang>

Nim

<lang nim>import strutils

let txt = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur." echo wordWrap(txt) echo "" echo wordWrap(txt, 45) </lang>

Output:
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus.
Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec
consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero
egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem
lacinia consectetur.

Lorem ipsum dolor sit amet, consectetur
adipiscing elit. Donec a diam lectus. Sed sit
amet ipsum mauris. Maecenas congue ligula ac
quam viverra nec consectetur ante hendrerit.
Donec et mollis dolor. Praesent et diam eget
libero egestas mattis sit amet vitae augue.
Nam tincidunt congue enim, ut porta lorem
lacinia consectetur.

OCaml

<lang ocaml>#load "str.cma"

let txt = "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything."

let () =

 let line_width = int_of_string Sys.argv.(1) in
 let words = Str.split (Str.regexp "[ \n]+") txt in
 let buf = Buffer.create 10 in
 let _ =
   List.fold_left (fun (width, sep) word ->
     let wlen = String.length word in
     let len = width + wlen + 1 in
     if len > line_width then
     begin
       Buffer.add_char buf '\n';
       Buffer.add_string buf word;
       (wlen, " ")
     end else begin
       Buffer.add_string buf sep;
       Buffer.add_string buf word;
       (len, " ")
     end
   ) (0, "") words
 in
 print_endline (Buffer.contents buf)</lang>

Testing:

$ ocaml word_wrap.ml 80 | wc -L
79
$ ocaml word_wrap.ml 72 | wc -L
72
$ ocaml word_wrap.ml 50 | wc -L
50

Ol

<lang scheme> (define (get-one-word start) (let loop ((chars #null) (end start))

  (let ((char (car end)))
     (if (has? (list #\space #\newline) char)
        (values (reverse chars) (force (cdr end)))
        (loop (cons char chars) (force (cdr end)))))))

(define (get-all-words string) (let loop ((words #null) (start (str-iter string)))

  (let* ((word next (get-one-word start)))
     (if (null? next)
        (reverse words)
        (loop (cons (runes->string word) words) next)))))

(define (get-one-line words n) (let loop ((line #null) (words words) (i 0))

  (let*((word (car words))
        (len (string-length word)))
     (if (null? (cdr words))
        (values (reverse (cons word line)) #null)
        (if (> (+ i len) n 1)
           (values (reverse line) words)
           (loop (cons word line) (cdr words) (+ i len 1)))))))

(define (get-all-lines words n) (let loop ((lines #null) (words words))

  (let* ((line words (get-one-line words n)))
     (if (null? words)
        (reverse (cons line lines))
        (loop (cons line lines) words)))))

(define (hyphenation width string) (let*((words (get-all-words string))

     (lines (get-all-lines words width)))
  lines))

</lang>

Output:
; <== (print "{0---------1+++++++++2---------3+++++++++4---------5+++++++++6---------7+++++++++}")
; <== (for-each print (hyphenation 80 "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face.  Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything. "))

; ==> {0---------1+++++++++2---------3+++++++++4---------5+++++++++6---------7+++++++++}
; ==> (In olden times when wishing still helped one, there lived a king whose daughters)
; ==> (were all beautiful, but the youngest was so beautiful that the sun itself, which)
; ==> (has seen so much, was astonished whenever it shone in her face.  Close by the)
; ==> (king's castle lay a great dark forest, and under an old lime-tree in the forest)
; ==> (was a well, and when the day was very warm, the king's child went out into the)
; ==> (forest and sat down by the side of the cool fountain, and when she was bored she)
; ==> (took a golden ball, and threw it up on high and caught it, and this ball was her)
; ==> (favorite)

PARI/GP

<lang parigp>wrap(s,len)={

 my(t="",cur);
 s=Vec(s);
 for(i=1,#s,
   if(s[i]==" ",
     if(cur>#t,
       print1(" "t);
       cur-=#t+1
     ,
       print1("\n"t);
       cur=len-#t
     );
     t=""
   ,
     t=concat(t,s[i])
   )
 );
 if(cur>#t,
   print1(" "t)
 ,
   print1("\n"t)
 )

}; King="And so let freedom ring from the prodigious hilltops of New Hampshire; let freedom ring from the mighty mountains of New York; let freedom ring from the heightening Alleghenies of Pennsylvania; let freedom ring from the snow-capped Rockies of Colorado; let freedom ring from the curvaceous slopes of California. But not only that: let freedom ring from Stone Mountain of Georgia; let freedom ring from Lookout Mountain of Tennessee; let freedom ring from every hill and molehill of Mississippi. From every mountainside, let freedom ring."; wrap(King, 75) wrap(King, 50)</lang>

Output:
And so let freedom ring from the prodigious hilltops of New Hampshire; let
freedom ring from the mighty mountains of New York; let freedom ring from
the heightening Alleghenies of Pennsylvania; let freedom ring from the
snow-capped Rockies of Colorado; let freedom ring from the curvaceous
slopes of California. But not only that: let freedom ring from Stone
Mountain of Georgia; let freedom ring from Lookout Mountain of Tennessee;
let freedom ring from every hill and molehill of Mississippi. From every
mountainside, let freedom ring.

And so let freedom ring from the prodigious
hilltops of New Hampshire; let freedom ring from
the mighty mountains of New York; let freedom ring
from the heightening Alleghenies of Pennsylvania;
let freedom ring from the snow-capped Rockies of
Colorado; let freedom ring from the curvaceous
slopes of California. But not only that: let
freedom ring from Stone Mountain of Georgia; let
freedom ring from Lookout Mountain of Tennessee;
let freedom ring from every hill and molehill of
Mississippi. From every mountainside, let freedom
ring.

Perl

Regex. Also showing degraded behavior on very long words: <lang perl>my $s = "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close-by-the-king's-castle-lay-a-great-dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.";

$s =~ s/\b\s+/ /g; $s =~ s/\s*$/\n\n/;

my $_ = $s; s/\s*(.{1,66})\s/$1\n/g, print;

$_ = $s; s/\s*(.{1,25})\s/$1\n/g, print;</lang>

Phix

<lang Phix>string s = substitute("""In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.""","\n"," ")

procedure word_wrap(string s, integer maxwidth)

   sequence words = split(s)
   string line = words[1]
   for i=2 to length(words) do
       string word = words[i]
       if length(line)+length(word)+1>maxwidth then
           puts(1,line&"\n")
           line = word
       else
           line &= " "&word
       end if
   end for
   puts(1,line&"\n")

end procedure

word_wrap(s,72) word_wrap(s,80)</lang>

Output:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face. Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face. Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.

PHP

<lang php><?php

$text = <<<ENDTXT If there's anything you need All you have to do is say You know you satisfy everything in me We shouldn't waste a single day

So don't stop me falling It's destiny calling A power I just can't deny It's never changing Can't you hear me, I'm saying I want you for the rest of my life

Together forever and never to part Together forever we two And don't you know I would move heaven and earth To be together forever with you ENDTXT;

// remove preexisting line breaks $text = str_replace( PHP_EOL, " " , $text );

echo wordwrap( $text, 20 ), PHP_EOL, PHP_EOL;

echo wordwrap( $text, 40 ), PHP_EOL, PHP_EOL;

echo wordwrap( $text, 80 ), PHP_EOL, PHP_EOL; </lang>

Output:
If there's anything
you need All you
have to do is say
You know you satisfy
everything in me We
shouldn't waste a
single day  So don't
stop me falling It's
destiny calling A
power I just can't
deny It's never
changing Can't you
hear me, I'm saying
I want you for the
rest of my life
Together forever and
never to part
Together forever we
two And don't you
know I would move
heaven and earth To
be together forever
with you

If there's anything you need All you
have to do is say You know you satisfy
everything in me We shouldn't waste a
single day  So don't stop me falling
It's destiny calling A power I just
can't deny It's never changing Can't you
hear me, I'm saying I want you for the
rest of my life  Together forever and
never to part Together forever we two
And don't you know I would move heaven
and earth To be together forever with
you

If there's anything you need All you have to do is say You know you satisfy
everything in me We shouldn't waste a single day  So don't stop me falling It's
destiny calling A power I just can't deny It's never changing Can't you hear me,
I'm saying I want you for the rest of my life  Together forever and never to
part Together forever we two And don't you know I would move heaven and earth To
be together forever with you

PicoLisp

'wrap' is a built-in. <lang PicoLisp>: (prinl (wrap 12 (chop "The quick brown fox jumps over the lazy dog"))) The quick brown fox jumps over the lazy dog -> "The quick^Jbrown fox^Jjumps over^Jthe lazy dog"</lang>

PL/I

<lang pli>*process source attributes xref or(!);

ww: proc Options(main);
/*********************************************************************
* 21.08-2013 Walter Pachl  derived from REXX version 2
*********************************************************************/
Dcl in  record input;
Dcl out record output;
On Endfile(in) z=' ';
Dcl z char(32767) Var;
Dcl s char(32767) Var Init();
dcl o Char(200) Var;
Dcl (i,w,p) Bin Fixed(31) Init(0);
w=72;
Read File(in) Into(z);
s=z;
Do Until(s=);
  Do i=w+1 to 1 by -1;
    If substr(s,i,1)= Then Leave;
    End;
  If i=0 Then
    p=index(s,' ');
  Else
    p=i;
  o=left(s,p);
  Write file(out) From(o);
  s=substr(s,p+1);
  If length(s)<200 Then Do;
    Read File(in) Into(z);
    s=s!!z;
    End;
  End;
End;</lang>

Test result using this:

/* REXX */
Call time 'R'
'set dd:in=h:\long2.txt,recsize(30000)' /* 1000036 characters with random length words */
'set dd:out=h:\longp.72,recsize(300)'
'ww'
Say time('E')
Output:
A nnnnnnnnnnnnnn ooooooooooooooo nnnnnnnnnnnnnn
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
iiiiiiiii LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL
etc.

PowerShell

Basic word wrap. <lang powershell>function wrap{ $divide=$args[0] -split " " $width=$args[1] $spaceleft=$width

foreach($word in $divide){ if($word.length+1 -gt $spaceleft){ $output+="`n$word " $spaceleft=$width-($word.length+1) } else { $output+="$word " $spaceleft-=$word.length+1 } }

return "$output`n" }

      1. The Main Thing...

$paragraph="Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur."

"`nLine width:30`n" wrap $paragraph 30 "=========================================================" "Line width:100`n" wrap $paragraph 100

      1. End script</lang>
Output:
Line width:30

Lorem ipsum dolor sit amet,
consectetur adipiscing elit.
Donec a diam lectus. Sed sit
amet ipsum mauris. Maecenas
congue ligula ac quam viverra
nec consectetur ante
hendrerit. Donec et mollis
dolor. Praesent et diam eget
libero egestas mattis sit
amet vitae augue. Nam
tincidunt congue enim, ut
porta lorem lacinia
consectetur.

=========================================================
Line width:100

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum
mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis
dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim,
ut porta lorem lacinia consectetur.

Pipeline Version

Slightly modified the previous to become the guts of this version. Now there is a default (80 characters) and a lower and upper limit for the -Width parameter. An unlimited number of strings may be passed to the helper function, New-WordWrap, through the pipeline. <lang PowerShell> function Out-WordWrap {

   [CmdletBinding()]
   [OutputType([string])]
   Param
   (
       [Parameter(Mandatory=$true,
                  ValueFromPipeline=$true,
                  Position=0)]
       [string]
       $Text,
       [Parameter(Mandatory=$false,
                  Position=1)]
       [ValidateRange(16,160)]
       [int]
       $Width = 80
   )
   Begin
   {
       function New-WordWrap ([string]$Text, [int]$Width)
       {
           [string[]]$words = $Text.Split()
           [string]$output  = ""
           [int]$remaining  = $Width
           foreach ($word in $words)
           {

if($word.Length + 1 -gt $remaining)

               {

$output += "`n$word " $remaining = $Width - ($word.Length + 1) }

               else
               {

$output += "$word " $remaining -= $word.Length + 1 }

           }
           return "$output`n"
       } 
   }
   Process
   {
       foreach ($paragraph in $Text)
       {
           New-WordWrap -Text $paragraph -Width $Width
       }
   }

} </lang> Grab some data and send it down the pipeline: <lang PowerShell> [string[]]$paragraphs = "Rebum everti delicata an vel, quo ut temporibus interpretaris, mea debet mnesarchum disputando ad. Id has dolorum contentiones, mel ea noster adipisci. Id persius appareat eos, aeque dolorum fastidii eam in. Partem assentior contentiones ut mea. Cu augue facilis fabellas cum, vix eu sanctus denique imperdiet, appareat percipit qui ex.",

                       "Nihil discere phaedrum at duo, no eum adhuc autem error. Quo aliquam delicata contentiones et, in sed ferri legimus sententiae, nihil solet docendi id eum. Ius ut meliore vulputate adipiscing, sea cu virtute praesent. Euripidis instructior est eu. Veri cotidieque ex vel, aliquam eruditi nusquam sea ne, eu wisi ubique ullamcorper est. Qui doctus epicuri ei. Cum esse detracto concludaturque ea, veri erant per ad, vide ancillae principes ius id.",
                       "Id disputando signiferumque nam, mei illud aeterno ut. Facilisis evertitur mei at. Qui in wisi fugit, eirmod comprehensam duo ei. Ea mel omnium nusquam, causae consequat appellantur per te.",
                       "Denique deseruisse ea his. Mundi scripta adolescens te ius, cum error persius cotidieque cu. Nobis apeirian ad his. Ius omnes gloriatur at, has eu tamquam inciderint, ubique commodo pro ad. Ex veri ceteros quo, duo an labores adolescens. Sed id quod verterem prodesset, magna eloquentiam ea eum.",
                       "Qui sanctus oportere quaerendum ex, usu vivendo accusamus posidonium an. Quo cu graece reprimique. Ea cum purto quando referrentur, tritani perfecto ne sit. Ne sit iusto ludus, ea ius eruditi dissentiunt, fabellas disputando eu vix. Te vim eripuit debitis tincidunt, in vim nonumes consetetur.",
                       "Affert exerci aperiri pri ea. Ut dicant essent corrumpit sit. Sea saepe nullam referrentur ut, vis dolores perfecto cu. At nam inimicus evertitur vulputate.",
                       "Dolor volutpat praesent vix ne, at soluta oblique admodum eum. Duis adipisci mea in, nam ut tota choro theophrastus. Ex scripta definitiones mei, augue doctus ne sed, munere posidonium eum id. Ad graeco audire per.",
                       "Sale salutatus et mei, mea elit illud adipiscing ei, cum ea sumo melius forensibus. Eu inani iusto oporteat eum, ei vix iisque saperet detraxit. Fabulas perpetua similique eam ne, noster corpora dissentiet qui ex, et qui integre graecis. Eripuit nonumes deterruisset an pro, ei ferri similique cum. Odio dolores inciderint ei vim, an est dolorum delicata temporibus, eu mea quis accumsan. Vel stet affert option at.",
                       "In gubergren voluptaria reprimique pro, option fuisset id est. Rebum delicata ad sea, ex vidit errem vis, mei at duis dicam sensibus. Nibh debet iudicabit has no, vim te dicit libris possim. Debet viderer consequuntur ea pro. Ex dicat iriure scripta pro.",
                       "An dicat diceret eligendi duo. Est cu equidem deterruisset, usu ad regione equidem, vim amet vero possim ex. Theophrastus conclusionemque ad quo, inimicus deseruisse voluptatibus eum et. Duis delectus mandamus an mei, usu timeam nostrum suscipiantur id."

$paragraphs | Out-WordWrap -Width 100 </lang>

Output:
Rebum everti delicata an vel, quo ut temporibus interpretaris, mea debet mnesarchum disputando ad. 
Id has dolorum contentiones, mel ea noster adipisci. Id persius appareat eos, aeque dolorum 
fastidii eam in. Partem assentior contentiones ut mea. Cu augue facilis fabellas cum, vix eu 
sanctus denique imperdiet, appareat percipit qui ex. 

Nihil discere phaedrum at duo, no eum adhuc autem error. Quo aliquam delicata contentiones et, in 
sed ferri legimus sententiae, nihil solet docendi id eum. Ius ut meliore vulputate adipiscing, sea 
cu virtute praesent. Euripidis instructior est eu. Veri cotidieque ex vel, aliquam eruditi nusquam 
sea ne, eu wisi ubique ullamcorper est. Qui doctus epicuri ei. Cum esse detracto concludaturque ea, 
veri erant per ad, vide ancillae principes ius id. 

Id disputando signiferumque nam, mei illud aeterno ut. Facilisis evertitur mei at. Qui in wisi 
fugit, eirmod comprehensam duo ei. Ea mel omnium nusquam, causae consequat appellantur per te. 

Denique deseruisse ea his. Mundi scripta adolescens te ius, cum error persius cotidieque cu. Nobis 
apeirian ad his. Ius omnes gloriatur at, has eu tamquam inciderint, ubique commodo pro ad. Ex veri 
ceteros quo, duo an labores adolescens. Sed id quod verterem prodesset, magna eloquentiam ea eum. 

Qui sanctus oportere quaerendum ex, usu vivendo accusamus posidonium an. Quo cu graece reprimique. 
Ea cum purto quando referrentur, tritani perfecto ne sit. Ne sit iusto ludus, ea ius eruditi 
dissentiunt, fabellas disputando eu vix. Te vim eripuit debitis tincidunt, in vim nonumes 
consetetur. 

Affert exerci aperiri pri ea. Ut dicant essent corrumpit sit. Sea saepe nullam referrentur ut, vis 
dolores perfecto cu. At nam inimicus evertitur vulputate. 

Dolor volutpat praesent vix ne, at soluta oblique admodum eum. Duis adipisci mea in, nam ut tota 
choro theophrastus. Ex scripta definitiones mei, augue doctus ne sed, munere posidonium eum id. Ad 
graeco audire per. 

Sale salutatus et mei, mea elit illud adipiscing ei, cum ea sumo melius forensibus. Eu inani iusto 
oporteat eum, ei vix iisque saperet detraxit. Fabulas perpetua similique eam ne, noster corpora 
dissentiet qui ex, et qui integre graecis. Eripuit nonumes deterruisset an pro, ei ferri similique 
cum. Odio dolores inciderint ei vim, an est dolorum delicata temporibus, eu mea quis accumsan. Vel 
stet affert option at. 

In gubergren voluptaria reprimique pro, option fuisset id est. Rebum delicata ad sea, ex vidit 
errem vis, mei at duis dicam sensibus. Nibh debet iudicabit has no, vim te dicit libris possim. 
Debet viderer consequuntur ea pro. Ex dicat iriure scripta pro. 

An dicat diceret eligendi duo. Est cu equidem deterruisset, usu ad regione equidem, vim amet vero 
possim ex. Theophrastus conclusionemque ad quo, inimicus deseruisse voluptatibus eum et. Duis 
delectus mandamus an mei, usu timeam nostrum suscipiantur id. 

PureBasic

<lang purebasic> DataSection

 Data.s "In olden times when wishing still helped one, there lived a king "+

"whose daughters were all beautiful, but the youngest was so beautiful "+ "that the sun itself, which has seen so much, was astonished whenever "+ "it shone-in-her-face. Close-by-the-king's castle lay a great dark "+ "forest, and under an old lime-tree in the forest was a well, and when "+ "the day was very warm, the king's child went out into the forest and "+ "sat down by the side of the cool-fountain, and when she was bored she "+ "took a golden ball, and threw it up on high and caught it, and this "+ "ball was her favorite plaything." EndDataSection

Procedure.i ww_pos(txt$,l.i)

 While Mid(txt$,l,1)<>Chr(32) And l>0 And Len(txt$)>l : l-1 : Wend
 If l>0 : ProcedureReturn l : Else : ProcedureReturn Len(Trim(txt$)) : EndIf

EndProcedure

Procedure WriteLine(txt$,ls.i)

 Shared d$,lw
 Select LCase(d$)
   Case "l" : PrintN(Mid(txt$,1,ls))    
   Case "r" : PrintN(RSet(Trim(Mid(txt$,1,ls)),lw,Chr(32)))
 EndSelect  

EndProcedure

Procedure main(txt$,lw.i)

 If Len(txt$)
   p=ww_pos(txt$,lw) : WriteLine(txt$,p) : ProcedureReturn main(LTrim(Right(txt$,Len(txt$)-p)),lw)
 EndIf

EndProcedure

Procedure.i MaxWordLen(txt$)

 For i=1 To CountString(txt$,Chr(32))+1
   wrd$=LTrim(StringField(txt$,i,Chr(32)))
   wrdl=Len(wrd$)+1 : If wrdl>l : l=wrdl : EndIf    
 Next
 ProcedureReturn l

EndProcedure

OpenConsole() Read.s t$ Print("Input line width: ") : lw=Val(Input()) : minL=MaxWordLen(t$) If lw<minL : lw=minL : PrintN("Min. line width "+Str(lw-1)) : EndIf Print("Input direction l:left r:rigth ") Repeat : d$=Inkey() : Delay(50) : Until FindString("lr",d$,1,#PB_String_NoCase) : PrintN(d$+#CRLF$) main(t$,lw) : Input() </lang>

Output:
Input line width: 40
Input direction l:left r:rigth l

In olden times when wishing still
helped one, there lived a king whose
daughters were all beautiful, but the
youngest was so beautiful that the sun
itself, which has seen so much, was
astonished whenever it
shone-in-her-face.  Close-by-the-king's
castle lay a great dark forest, and
under an old lime-tree in the forest
was a well, and when the day was very
warm, the king's child went out into
the forest and sat down by the side of
the cool-fountain, and when she was
bored she took a golden ball, and threw
it up on high and caught it, and this
ball was her favorite plaything.
Input line width: 40
Input direction l:left r:rigth r

       In olden times when wishing still
    helped one, there lived a king whose
   daughters were all beautiful, but the
  youngest was so beautiful that the sun
     itself, which has seen so much, was
                  astonished whenever it
 shone-in-her-face.  Close-by-the-king's
     castle lay a great dark forest, and
    under an old lime-tree in the forest
   was a well, and when the day was very
    warm, the king's child went out into
  the forest and sat down by the side of
     the cool-fountain, and when she was
 bored she took a golden ball, and threw
   it up on high and caught it, and this
        ball was her favorite plaything.

Python

<lang python>>>> import textwrap >>> help(textwrap.fill) Help on function fill in module textwrap:

fill(text, width=70, **kwargs)

   Fill a single paragraph of text, returning a new string.
   
   Reformat the single paragraph in 'text' to fit in lines of no more
   than 'width' columns, and return a new string containing the entire
   wrapped paragraph.  As with wrap(), tabs are expanded and other
   whitespace characters converted to space.  See TextWrapper class for
   available keyword args to customize wrapping behaviour.

>>> txt = \ Reformat the single paragraph in 'text' to fit in lines of no more than 'width' columns, and return a new string containing the entire wrapped paragraph. As with wrap(), tabs are expanded and other whitespace characters converted to space. See TextWrapper class for available keyword args to customize wrapping behaviour. >>> print(textwrap.fill(txt, width=75)) Reformat the single paragraph in 'text' to fit in lines of no more than 'width' columns, and return a new string containing the entire wrapped paragraph. As with wrap(), tabs are expanded and other whitespace characters converted to space. See TextWrapper class for available keyword args to customize wrapping behaviour. >>> print(textwrap.fill(txt, width=45)) Reformat the single paragraph in 'text' to fit in lines of no more than 'width' columns, and return a new string containing the entire wrapped paragraph. As with wrap(), tabs are expanded and other whitespace characters converted to space. See TextWrapper class for available keyword args to customize wrapping behaviour. >>> print(textwrap.fill(txt, width=85)) Reformat the single paragraph in 'text' to fit in lines of no more than 'width' columns, and return a new string containing the entire wrapped paragraph. As with wrap(), tabs are expanded and other whitespace characters converted to space. See TextWrapper class for available keyword args to customize wrapping behaviour. >>> </lang>

R

Using the base library

Use strwrap(): <lang rsplus>> x <- "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur. " > cat(paste(strwrap(x=c(x, "\n"), width=80), collapse="\n")) Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur. > cat(paste(strwrap(x=c(x, "\n"), width=60), collapse="\n")) Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur.</lang>

Using the stringr tidyverse library

Another option, using stringr::str_wrap <lang rsplus> > x <- "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur. " > cat(stringr::str_wrap(x, 60)) Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam viverra nec consectetur ante hendrerit. Donec et mollis dolor. Praesent et diam eget libero egestas mattis sit amet vitae augue. Nam tincidunt congue enim, ut porta lorem lacinia consectetur. </lang>

Racket

Using a library function: <lang Racket>

  1. lang at-exp racket

(require scribble/text/wrap) (define text

 @(λ xs (regexp-replace* #rx" *\n *" (string-append* xs) " ")){
   In olden times when wishing still helped one, there lived a king whose
   daughters were all beautiful, but the youngest was so beautiful that the
   sun itself, which has seen so much, was astonished whenever it shone in her
   face.  Close by the king's castle lay a great dark forest, and under an old
   lime-tree in the forest was a well, and when the day was very warm, the
   king's child went out into the forest and sat down by the side of the cool
   fountain, and when she was bored she took a golden ball, and threw it up on
   high and caught it, and this ball was her favorite plaything.})

(for-each displayln (wrap-line text 60)) </lang>

Explicit (and simple) implementation: <lang racket>

  1. lang racket

(define (wrap words width)

 (define (maybe-cons xs xss)
   (if (empty? xs) xss (cons xs xss)))  
 (match/values
   (for/fold ([lines '()] [line '()] [left width]) ([w words])
     (define n (string-length w))
     (cond
       [(> n width) ; word longer than line => line on its own
        (values (cons (list w) (maybe-cons line lines)) '() width)]
       [(> n left)  ; not enough space left => new line
        (values (cons line lines) (list w) (- width n 1))]
       [else
        (values lines (cons w line) (- left n 1))]))
   [(lines line _)
    (apply string-append
           (for/list ([line (reverse (cons line lines))])
             (string-join line #:after-last "\n")))]))
Usage

(wrap (string-split text) 70) </lang>

Raku

(formerly Perl 6) <lang perl6>my $s = "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close-by-the-king's-castle-lay-a-great-dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.";

$s ~~ s:g/»\s+/ /; $s ~~ s/\s*$/\n\n/;

say $s.subst(/ \s* (. ** 1..66) \s /, -> $/ { "$0\n" }, :g); say $s.subst(/ \s* (. ** 1..25) \s /, -> $/ { "$0\n" }, :g);</lang>

REXX

version 0

This version was the original (of version 1) and has no error checking and only does left-margin justification. <lang rexx>/*REXX program reads a file and displays it to the screen (with word wrap). */ parse arg iFID width . /*obtain optional arguments from the CL*/ if iFID== | iFID=="," then iFID='LAWS.TXT' /*Not specified? Then use the default.*/ if width== | width=="," then width=linesize() /* " " " " " " */ @= /*number of words in the file (so far).*/

           do  while lines(iFID)\==0            /*read from the file until End-Of-File.*/
           @=@ linein(iFID)                     /*get a record  (line of text).        */
           end   /*while*/

$=word(@,1) /*initialize $ with the first word. */

           do k=2  for words(@)-1;  x=word(@,k) /*parse until text (@) exhausted.      */
           _=$ x                                /*append it to the  $  list and test.  */
           if length(_)>=width  then do;  say $ /*this word a bridge too far?    > w.  */
                                          _=x   /*assign this word to the next line.   */
                                    end
           $=_                                  /*new words (on a line)  are OK so far.*/
           end   /*m*/

if $\== then say $ /*handle any residual words (overflow).*/

                                                /*stick a fork in it,  we're all done. */</lang>

output   is the same as version 1 using the   Left   option (the default).

version 1

The input for this program is in a file   (named LAWS.TXT).

The default width of the output is the current terminal width   (normally, this would be the window's width).
If the terminal width (or window's width) is indeterminable, then   80   is used.
The width can be expressed as a percentage (i.e.:   50%)   which signifies to use ½ of the terminal's width).
No hyphenation (or de-hyphenation) is attempted.
Words longer than the width of the output are acceptable and are shown (with no truncation), a simple change could be made to issue a notification.
Some rudimentary error checking is performed.

Types of word wrapping (justification) are   (only the first character is significant):

                 Center:       ◄centered►
                 Right:  ────────►right margin
                 Left:   left margin◄─────────
                 Both:   ◄───both margins────►

(Left   is the default.)

This version was modified (for speed at the expense of simplicity) to accommodate faster processing of large files.
Instead of appending lines of a file to a character string, the words are picked off and stored in a stemmed array.
This decreases the amount of work that REXX has to do to retrieve (get) the next word in the (possibly) ginormous string. <lang rexx>/*REXX program reads a file and displays it to the screen (with word wrap). */ parse arg iFID width kind _ . /*obtain optional arguments from the CL*/ if iFID== | iFID=="," then iFID = 'LAWS.TXT' /*Not specified? Then use the default.*/ if width== |width=="," then width= linesize() /* " " " " " " */ if right(width, 1) =='%' then width= linesize() * translate(width, , "%")  % 100 if kind== | kind=="," then kind= 'Left' /*Default? Then use the default: LEFT */ just= left(kind, 1); upper just /*use 1st char of JUSTIFY, uppercased.*/ if pos(just, 'BCLR')==0 then call err "KIND (3rd arg) is illegal:" kind if _\== then call err "too many arguments specified." _ if \datatype(width,'W') then call err "WIDTH (2nd arg) isn't an integer:" width n=0 /*the number of words in the file. */

           do j=0  while lines(iFID)\==0        /*read from the file until End-Of-File.*/
           _=linein(iFID)                       /*get a record  (line of text).        */
                do  until _==;      n= n + 1  /*extract some words  (or maybe not).  */
                parse var _   @.n  _            /*obtain and assign next word in text. */
                end   /*until*/                 /*parse 'til the line of text is null. */
           end        /*j*/

if j==0 then call err 'file' iFID "not found." if n==0 then call err 'file' iFID "is empty (or has no words)" $=@.1 /*initialize $ string with first word*/

           do m=2  for n-1;           x= @.m    /*parse until text  (@)  is exhausted. */
           _= $ x                               /*append it to the  $  string and test.*/
           if length(_)>= width  then call tell /*this word a bridge too far?   > w    */
           $= _                                 /*the new words are OK  (so far).      */
           end   /*m*/

call tell /*handle any residual words (if any). */ exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ err: say; say '***error***'; say; say arg(1); say; say; exit 13 /*──────────────────────────────────────────────────────────────────────────────────────*/ tell: if $== then return /* [↓] the first word may be too long.*/

     w=max(width, length($) )                   /*don't truncate long words  (> w).    */
           select
           when just=='L'  then $=  strip($)    /*left ◄────────                       */
           when just=='R'  then $=  right($, w) /*──────► right                        */
           when just=='B'  then $=justify($, w) /*◄────both────►                       */
           when just=='C'  then $= center($, w) /*  ◄centered►                         */
           end   /*select*/
     say $                                      /*display the line of words to terminal*/
     _= x                                       /*handle any word overflow.            */
     return                                     /*go back and keep truckin'.           */</lang>

This REXX program makes use of   LINESIZE   REXX program (or BIF) which is used to determine the screen width (or linesize) of the terminal (console).

The   LINESIZE.REX   REXX program is included here   ──►   LINESIZE.REX.

input file:

     ────────── Computer programming laws ──────────
 The Primal Scenario  -or-  Basic Datum of Experience:
    ∙ Systems in general work poorly or not at all.
    ∙ Nothing complicated works.
    ∙ Complicated systems seldom exceed 5% efficiency.
    ∙ There is always a fly in the ointment.
 The Fundamental Theorem:
    ∙ New systems generate new problems.
 Occam's Razor:
    ∙ Systems should not be unnecessarily multiplied.
 The Law of Conservation of Energy:
    ∙ The total amount of energy in the universe is constant.
    ∙ Systems operate by redistributing energy into different forms and into accumulations of different sizes.
 Laws of Growth:
    ∙ Systems tend to grow, and as they grow, they encroach.
 The Big-Bang Theorem of Systems-Cosmology:
    ∙ Systems tend to expand to fill the known universe.
 Parkinson's Extended Law:
    ∙ The system itself tends to expand at 5-6% per annum.
 The Generalized Uncertainty Principle:
    ∙ Systems display antics.
    ∙ Complicated systems produce unexpected outcomes.
    ∙ The total behavior of large systems cannot be predicted.
 The Non-Additivity Theorem of Systems-Behavior -or- Climax Design Theorem:
    ∙ A large system, produced by expanding the dimensions of a smaller system, does not behave like the smaller system.
 LeChateliers's Principle:
    ∙ Complex systems tend to oppose their own proper function.
    ∙ Systems get in the way.
    ∙ The system always kicks back.
    ∙ Positive feedback is dangerous.
 Functionary's Falsity:
    ∙ People in systems do not do what the system says they are doing.
    ∙ The function performed by a system is not operationally identical to the function of the same name performed by a man.
    ∙ A function performed by a larger system is not operationally identical to the function of the same name performed by a smaller system.
 The Fundamental Law of Administrative Workings:
    ∙ Things are what they are reported to be.
    ∙ The real world is whatever is reported to the system.
    ∙ If it isn't official; it didn't happen.
    ∙ If it's made in Detroit, it must be an automobile.
    ∙ A system is no better than its sensory organs.
    ∙ To those within a system, the outside reality tends to pale and disappear.
    ∙ Systems attract systems-people.
    ∙ For every human system, there is a type of person adapted to thrive on it or in it.
    ∙ The bigger the system, the narrower and more specialized the interface with individuals.
 Administrator's Anxiety:
    ∙ Pushing on the systems doesn't help.  It just makes things worse.
    ∙ A complex system cannot be "made" to work.  It either works or it doesn't.
    ∙ A simple system, designed from scratch, sometimes works.
    ∙ A simple system may or may not work.
    ∙ Some complex systems actually work.
    ∙ If a system is working, leave it alone.
    ∙ A complex system that works is invariably found to have evolved from a simple system that works.
    ∙ A complex system designed from scratch never works and cannot be patched up to make it work.  You have to start over, beginning with a working simple system.
    ∙ Programs never run the first time.
    ∙ Complex programs never run.
    ∙ Anything worth doing once will probably have to be done twice.
 The Functional indeterminacy Theorem:
    ∙ In complex systems, malfunction and even total nonfunction may not be detectable for long periods, if ever.
 The Kantian Hypothesis  -or-  Know-Nothing Theorem:
    ∙ Large complex systems are beyond human capacity to evaluate.
 The Newtonian Lay of Systems-Inertia:
    ∙ A system that performs a certain way will continue to operate in that way regardless of the need of of changed conditions.
    ∙ A system continues to do its thing, regardless of need.
    ∙ Systems develop goals of their own the instant they come into being.
    ∙ Intrasystem goals come first.
 Failure-Mode Theorems:
    ∙ Complex systems usually operate in failure mode.
    ∙ A complex system can fail in a infinite number of ways.
    ∙ If anything can go wrong, it will.
    ∙ The mode of failure of a complex system cannot ordinarily be predicted from its structure.
    ∙ The crucial variables are discovered by accident.
    ∙ The larger the system, the greater the probability of unexpected failure.
    ∙ "Success" or "function" in any system may be failure in the larger or smaller systems to which the system is connected.
    ∙ In setting up a new system, tread softly.  You may be disturbing another system that is actually working.
 The Fail-Safe Theorem:
    ∙ When a fail-safe system fails, it fails by failing to fail safe.
    ∙ Complex systems tend to produce complex responses (not solutions) to problems.
    ∙ Great advances are not produced by systems designed to produce great advances.
    ∙ Loose systems last longer and work better.
    ∙ Efficient systems are dangerous to themselves and to others.
 The Vector Theory of Systems:
    ∙ Systems run better when designed to run downhill.
    ∙ Systems aligned with human motivational vectors will sometimes work.  Systems opposing such vectors work poorly or not at all.
 Advanced Systems Theories:
    ∙ Everything is a system.
    ∙ Everything is a part of a larger system.
    ∙ The universe is infinitely systematized, both upward [larger systems] and downward [smaller systems].
    ∙ All systems are infinitely complex.  (The illusion of simplicity comes from focusing attention on one or a few variables.)
    ∙ Parameters are variables traveling under an assumed name. 
output   when using the input of:     ,   155
────────── Computer programming laws ────────── The Primal Scenario -or- Basic Datum of Experience: ∙ Systems in general work poorly or not at all. ∙
Nothing complicated works. ∙ Complicated systems seldom exceed 5% efficiency. ∙ There is always a fly in the ointment. The Fundamental Theorem: ∙ New
systems generate new problems. Occam's Razor: ∙ Systems should not be unnecessarily multiplied. The Law of Conservation of Energy: ∙ The total amount of
energy in the universe is constant. ∙ Systems operate by redistributing energy into different forms and into accumulations of different sizes. Laws of
Growth: ∙ Systems tend to grow, and as they grow, they encroach. The Big-Bang Theorem of Systems-Cosmology: ∙ Systems tend to expand to fill the known
universe. Parkinson's Extended Law: ∙ The system itself tends to expand at 5-6% per annum. The Generalized Uncertainty Principle: ∙ Systems display
antics. ∙ Complicated systems produce unexpected outcomes. ∙ The total behavior of large systems cannot be predicted. The Non-Additivity Theorem of
Systems-Behavior -or- Climax Design Theorem: ∙ A large system, produced by expanding the dimensions of a smaller system, does not behave like the smaller
system. LeChateliers's Principle: ∙ Complex systems tend to oppose their own proper function. ∙ Systems get in the way. ∙ The system always kicks back. ∙
Positive feedback is dangerous. Functionary's Falsity: ∙ People in systems do not do what the system says they are doing. ∙ The function performed by a
system is not operationally identical to the function of the same name performed by a man. ∙ A function performed by a larger system is not operationally
identical to the function of the same name performed by a smaller system. The Fundamental Law of Administrative Workings: ∙ Things are what they are
reported to be. ∙ The real world is whatever is reported to the system. ∙ If it isn't official; it didn't happen. ∙ If it's made in Detroit, it must be an
automobile. ∙ A system is no better than its sensory organs. ∙ To those within a system, the outside reality tends to pale and disappear. ∙ Systems
attract systems-people. ∙ For every human system, there is a type of person adapted to thrive on it or in it. ∙ The bigger the system, the narrower and
more specialized the interface with individuals. Administrator's Anxiety: ∙ Pushing on the systems doesn't help. It just makes things worse. ∙ A complex
system cannot be "made" to work. It either works or it doesn't. ∙ A simple system, designed from scratch, sometimes works. ∙ A simple system may or may
not work. ∙ Some complex systems actually work. ∙ If a system is working, leave it alone. ∙ A complex system that works is invariably found to have
evolved from a simple system that works. ∙ A complex system designed from scratch never works and cannot be patched up to make it work. You have to start
over, beginning with a working simple system. ∙ Programs never run the first time. ∙ Complex programs never run. ∙ Anything worth doing once will probably
have to be done twice. The Functional indeterminacy Theorem: ∙ In complex systems, malfunction and even total nonfunction may not be detectable for long
periods, if ever. The Kantian Hypothesis -or- Know-Nothing Theorem: ∙ Large complex systems are beyond human capacity to evaluate. The Newtonian Lay of
Systems-Inertia: ∙ A system that performs a certain way will continue to operate in that way regardless of the need of of changed conditions. ∙ A system
continues to do its thing, regardless of need. ∙ Systems develop goals of their own the instant they come into being. ∙ Intrasystem goals come first.
Failure-Mode Theorems: ∙ Complex systems usually operate in failure mode. ∙ A complex system can fail in a infinite number of ways. ∙ If anything can go
wrong, it will. ∙ The mode of failure of a complex system cannot ordinarily be predicted from its structure. ∙ The crucial variables are discovered by
accident. ∙ The larger the system, the greater the probability of unexpected failure. ∙ "Success" or "function" in any system may be failure in the larger
or smaller systems to which the system is connected. ∙ In setting up a new system, tread softly. You may be disturbing another system that is actually
working. The Fail-Safe Theorem: ∙ When a fail-safe system fails, it fails by failing to fail safe. ∙ Complex systems tend to produce complex responses
(not solutions) to problems. ∙ Great advances are not produced by systems designed to produce great advances. ∙ Loose systems last longer and work better.
∙ Efficient systems are dangerous to themselves and to others. The Vector Theory of Systems: ∙ Systems run better when designed to run downhill. ∙ Systems
aligned with human motivational vectors will sometimes work. Systems opposing such vectors work poorly or not at all. Advanced Systems Theories: ∙
Everything is a system. ∙ Everything is a part of a larger system. ∙ The universe is infinitely systematized, both upward [larger systems] and downward
[smaller systems]. ∙ All systems are infinitely complex. (The illusion of simplicity comes from focusing attention on one or a few variables.) ∙
output   when using the input:     ,   80
────────── Computer programming laws ────────── The Primal Scenario -or- Basic
Datum of Experience: ∙ Systems in general work poorly or not at all. ∙ Nothing
complicated works. ∙ Complicated systems seldom exceed 5% efficiency. ∙ There
is always a fly in the ointment. The Fundamental Theorem: ∙ New systems
generate new problems. Occam's Razor: ∙ Systems should not be unnecessarily
multiplied. The Law of Conservation of Energy: ∙ The total amount of energy in
the universe is constant. ∙ Systems operate by redistributing energy into
different forms and into accumulations of different sizes. Laws of Growth: ∙
Systems tend to grow, and as they grow, they encroach. The Big-Bang Theorem of
Systems-Cosmology: ∙ Systems tend to expand to fill the known universe.
Parkinson's Extended Law: ∙ The system itself tends to expand at 5-6% per
annum. The Generalized Uncertainty Principle: ∙ Systems display antics. ∙
Complicated systems produce unexpected outcomes. ∙ The total behavior of large
systems cannot be predicted. The Non-Additivity Theorem of Systems-Behavior
-or- Climax Design Theorem: ∙ A large system, produced by expanding the
dimensions of a smaller system, does not behave like the smaller system.
LeChateliers's Principle: ∙ Complex systems tend to oppose their own proper
function. ∙ Systems get in the way. ∙ The system always kicks back. ∙ Positive
feedback is dangerous. Functionary's Falsity: ∙ People in systems do not do
what the system says they are doing. ∙ The function performed by a system is
not operationally identical to the function of the same name performed by a
man. ∙ A function performed by a larger system is not operationally identical
to the function of the same name performed by a smaller system. The Fundamental
Law of Administrative Workings: ∙ Things are what they are reported to be. ∙
The real world is whatever is reported to the system. ∙ If it isn't official;
it didn't happen. ∙ If it's made in Detroit, it must be an automobile. ∙ A
system is no better than its sensory organs. ∙ To those within a system, the
outside reality tends to pale and disappear. ∙ Systems attract systems-people.
∙ For every human system, there is a type of person adapted to thrive on it or
in it. ∙ The bigger the system, the narrower and more specialized the interface
with individuals. Administrator's Anxiety: ∙ Pushing on the systems doesn't
help. It just makes things worse. ∙ A complex system cannot be "made" to work.
It either works or it doesn't. ∙ A simple system, designed from scratch,
sometimes works. ∙ A simple system may or may not work. ∙ Some complex systems
actually work. ∙ If a system is working, leave it alone. ∙ A complex system
that works is invariably found to have evolved from a simple system that works.
∙ A complex system designed from scratch never works and cannot be patched up
to make it work. You have to start over, beginning with a working simple
system. ∙ Programs never run the first time. ∙ Complex programs never run. ∙
Anything worth doing once will probably have to be done twice. The Functional
indeterminacy Theorem: ∙ In complex systems, malfunction and even total
nonfunction may not be detectable for long periods, if ever. The Kantian
Hypothesis -or- Know-Nothing Theorem: ∙ Large complex systems are beyond human
capacity to evaluate. The Newtonian Lay of Systems-Inertia: ∙ A system that
performs a certain way will continue to operate in that way regardless of the
need of of changed conditions. ∙ A system continues to do its thing, regardless
of need. ∙ Systems develop goals of their own the instant they come into being.
∙ Intrasystem goals come first. Failure-Mode Theorems: ∙ Complex systems
usually operate in failure mode. ∙ A complex system can fail in a infinite
number of ways. ∙ If anything can go wrong, it will. ∙ The mode of failure of a
complex system cannot ordinarily be predicted from its structure. ∙ The crucial
variables are discovered by accident. ∙ The larger the system, the greater the
probability of unexpected failure. ∙ "Success" or "function" in any system may
be failure in the larger or smaller systems to which the system is connected. ∙
In setting up a new system, tread softly. You may be disturbing another system
that is actually working. The Fail-Safe Theorem: ∙ When a fail-safe system
fails, it fails by failing to fail safe. ∙ Complex systems tend to produce
complex responses (not solutions) to problems. ∙ Great advances are not
produced by systems designed to produce great advances. ∙ Loose systems last
longer and work better. ∙ Efficient systems are dangerous to themselves and to
others. The Vector Theory of Systems: ∙ Systems run better when designed to run
downhill. ∙ Systems aligned with human motivational vectors will sometimes
work. Systems opposing such vectors work poorly or not at all. Advanced Systems
Theories: ∙ Everything is a system. ∙ Everything is a part of a larger system.
∙ The universe is infinitely systematized, both upward [larger systems] and
downward [smaller systems]. ∙ All systems are infinitely complex. (The illusion
of simplicity comes from focusing attention on one or a few variables.) ∙
Parameters are variables traveling under an assumed name.
output     [justified]   when specifying: , 80 both
────────── Computer programming laws ──────────  The Primal Scenario -or- Basic
Datum of Experience: ∙ Systems in general  work poorly or not at all. ∙ Nothing
complicated works. ∙ Complicated systems  seldom  exceed 5% efficiency. ∙ There
is always a  fly  in  the  ointment.  The  Fundamental  Theorem:  ∙ New systems
generate new problems. Occam's  Razor:  ∙  Systems  should not be unnecessarily
multiplied. The Law of Conservation of Energy:  ∙ The total amount of energy in
the universe is  constant.  ∙  Systems  operate  by  redistributing energy into
different forms and into accumulations  of  different  sizes. Laws of Growth: ∙
Systems tend to grow, and as they  grow, they encroach. The Big-Bang Theorem of
Systems-Cosmology: ∙  Systems  tend  to  expand  to  fill  the  known universe.
Parkinson's Extended Law: ∙  The  system  itself  tends  to  expand at 5-6% per
annum. The  Generalized  Uncertainty  Principle:  ∙  Systems  display antics. ∙
Complicated systems produce unexpected outcomes.  ∙ The total behavior of large
systems cannot be  predicted.  The  Non-Additivity  Theorem of Systems-Behavior
-or- Climax  Design  Theorem:  ∙  A  large  system,  produced  by expanding the
dimensions of a  smaller  system,  does  not  behave  like  the smaller system.
LeChateliers's Principle: ∙ Complex  systems  tend  to  oppose their own proper
function. ∙ Systems get in the way.  ∙ The system always kicks back. ∙ Positive
feedback is dangerous. Functionary's  Falsity:  ∙  People  in systems do not do
what the system says they are  doing.  ∙  The function performed by a system is
not operationally identical to the  function  of  the  same name performed by a
man. ∙ A function performed by  a  larger system is not operationally identical
to the function of the same name performed by a smaller system. The Fundamental
Law of Administrative Workings: ∙ Things  are  what  they are reported to be. ∙
The real world is whatever is reported  to  the system. ∙ If it isn't official;
it didn't happen. ∙ If it's  made  in  Detroit,  it  must be an automobile. ∙ A
system is no better than its  sensory  organs.  ∙ To those within a system, the
outside reality tends to pale  and disappear. ∙ Systems attract systems-people.
∙ For every human system, there is a  type of person adapted to thrive on it or
in it. ∙ The bigger the system, the narrower and more specialized the interface
with individuals. Administrator's  Anxiety:  ∙  Pushing  on the systems doesn't
help. It just makes things worse. ∙  A complex system cannot be "made" to work.
It either works  or  it  doesn't.  ∙  A  simple  system, designed from scratch,
sometimes works. ∙ A simple system may  or may not work. ∙ Some complex systems
actually work. ∙ If a system  is  working,  leave  it alone. ∙ A complex system
that works is invariably found to have evolved from a simple system that works.
∙ A complex system designed from  scratch  never works and cannot be patched up
to make it work.  You  have  to  start  over,  beginning  with a working simple
system. ∙ Programs never run the  first  time.  ∙ Complex programs never run. ∙
Anything worth doing once will probably  have  to be done twice. The Functional
indeterminacy  Theorem:  ∙  In  complex  systems,  malfunction  and  even total
nonfunction may not  be  detectable  for  long  periods,  if  ever. The Kantian
Hypothesis -or- Know-Nothing Theorem: ∙  Large complex systems are beyond human
capacity to evaluate. The  Newtonian  Lay  of  Systems-Inertia: ∙ A system that
performs a certain way will continue  to  operate in that way regardless of the
need of of changed conditions. ∙ A system continues to do its thing, regardless
of need. ∙ Systems develop goals of their own the instant they come into being.
∙ Intrasystem  goals  come  first.  Failure-Mode  Theorems:  ∙  Complex systems
usually operate in failure mode.  ∙  A  complex  system  can fail in a infinite
number of ways. ∙ If anything can go wrong, it will. ∙ The mode of failure of a
complex system cannot ordinarily be predicted from its structure. ∙ The crucial
variables are discovered by accident. ∙  The larger the system, the greater the
probability of unexpected failure. ∙ "Success"  or "function" in any system may
be failure in the larger or smaller systems to which the system is connected. ∙
In setting up a new system, tread  softly. You may be disturbing another system
that is actually working.  The  Fail-Safe  Theorem:  ∙  When a fail-safe system
fails, it fails by failing  to  fail  safe.  ∙  Complex systems tend to produce
complex responses  (not  solutions)  to  problems.  ∙  Great  advances  are not
produced by systems designed to  produce  great  advances. ∙ Loose systems last
longer and work better. ∙ Efficient  systems are dangerous to themselves and to
others. The Vector Theory of Systems: ∙ Systems run better when designed to run
downhill. ∙ Systems  aligned  with  human  motivational  vectors will sometimes
work. Systems opposing such vectors work poorly or not at all. Advanced Systems
Theories: ∙ Everything is a system. ∙  Everything is a part of a larger system.
∙ The universe is  infinitely  systematized,  both  upward [larger systems] and
downward [smaller systems]. ∙ All systems are infinitely complex. (The illusion
of simplicity comes from  focusing  attention  on  one  or  a few variables.) ∙
Parameters    are    variables    traveling     under    an    assumed    name.

version 2

<lang rexx>/* REXX ***************************************************************

  • 20.08.2013 Walter Pachl "my way"
  • 23.08.2013 Walter Pachl changed to use lastpos bif
                                                                                                                                            • /

Parse Arg w oid=w'.xxx'; 'erase' oid Call o left(copies('123456789.',20),w) s='She should have died hereafter;' ,

 'There would have been a time for such a word.' ,
 'Tomorrow, and tomorrow, and tomorrow, and so on'

Call ow s Exit ow:

 Parse Arg s
 s=s' '
 Do While length(s)>w
   i=lastpos(' ',s,w+1) /* instead of loop */
   If i=0 Then
     p=pos(' ',s)
   Else
     p=i
   Call o left(s,p)
   s=substr(s,p+1)
   End
 If s> Then
   Call o s
 Return

o:Return lineout(oid,arg(1))</lang>

Output:

for widths 72 and 9

123456789.123456789.123456789.123456789.123456789.123456789.123456789.12
She should have died hereafter; There would have been a time for such a
word. Tomorrow, and tomorrow, and tomorrow, and so on

123456789
She
should
have died
hereafter;
There
would
have been
a time
for such
a word.
Tomorrow,
and
tomorrow,
and
tomorrow,
and so on

Ring

<lang ring>

  1. Project : Word wrap

load "stdlib.ring"

doc = "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything."

wordwrap(doc,72) wordwrap(doc,80)

func wordwrap(doc, maxline)

       words = split(doc, " ")
       line = words[1]
       for i=2 to len(words)
            word = words[i]
           if len(line)+len(word)+1 > maxline
              see line + nl
              line = word
           else
              line = line + " " + word
          ok
       next
       see line + nl + nl

</lang> Output:

In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face. Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.

In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face. Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.

Ruby

<lang ruby>class String

 def wrap(width)
   txt = gsub("\n", " ")
   para = []
   i = 0
   while i < length 
     j = i + width
     j -= 1 while j != txt.length && j > i + 1 && !(txt[j] =~ /\s/)
     para << txt[i ... j]
     i = j + 1
   end
   para
 end

end

text = <<END In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything. END

[72,80].each do |w|

 puts "." * w
 puts text.wrap(w)

end</lang>

Output:
........................................................................
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face.  Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.
................................................................................
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face.  Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.

Run BASIC

Word Wrap style for different browsers. This automatically adjusts the text if the browser window is stretched in any direction <lang runbasic>doc$ = "In olden times when wishing still helped one, there lived a king ";_ "whose daughters were all beautiful, but the youngest was so beautiful ";_ "that the sun itself, which has seen so much, was astonished whenever ";_ "it shone in her face."

wrap$ = " style='white-space: pre-wrap;white-space: -moz-pre-wrap;white-space: -pre-wrap;";_

               "white-space: -o-pre-wrap;word-wrap: break-word'"

html "

<tr" + wrap$ +" valign=top>" html "
" + doc$ + "" + doc$ + "

"</lang>

output will adjust as you stretch the browser and maintain a 60 to 40 ratio of the width of the screen.

---------- at 60%-----------------------                         | -------- at 40%----------------------
In olden times when wishing still helped one, there lived a king | In olden times when wishing still helped 
whose daughters were all beautiful, but the youngest was so      | one, there lived a king whose daughters 
beautiful that the sun itself, which has seen so much, was       | were all beautiful, but the youngest was 
astonished whenever it shone in her face.	                 | so beautiful that the sun itself, which 
								 | has seen so much, was astonished whenever
								 | it shone in her face.

Without Browser <lang runbasic>doc$ = "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything."

input "Width"; width ' user specifies width

while word$(doc$,i + 1," ") <> ""

 i = i + 1
 thisWord$ = word$(doc$,i," ") + " "
 if word$(thisWord$,2,chr$(13)) <> "" then thisWord$ = word$(thisWord$,2,chr$(13)) + " " ' strip the <CR>
 if len(docOut$) + len(thisWord$) > width then
   print docOut$
   docOut$ = ""
 end if
 docOut$ = docOut$ + thisWord$

wend print docOut$</lang>

Scala

Intuitive approach

Library: Scala

<lang scala>import java.util.StringTokenizer

object WordWrap extends App {

 final val defaultLineWidth = 80
 final val spaceWidth = 1
 def letsWrap(text: String, lineWidth: Int = defaultLineWidth) = {
   println(s"\n\nWrapped at: $lineWidth")
   println("." * lineWidth)
   minNumLinesWrap(ewd, lineWidth)
 }
 final def ewd = "Vijftig jaar geleden publiceerde Edsger Dijkstra zijn kortstepadalgoritme. Daarom een kleine ode" +
   " aan de in 2002 overleden Dijkstra, iemand waar we als Nederlanders best wat trotser op mogen zijn. Dijkstra was" +
   " een van de eerste programmeurs van Nederland. Toen hij in 1957 trouwde, werd het beroep computerprogrammeur door" +
   " de burgerlijke stand nog niet erkend en uiteindelijk gaf hij maar `theoretische natuurkundige’ op.\nZijn" +
   " beroemdste resultaat is het kortstepadalgoritme, dat de kortste verbinding vindt tussen twee knopen in een graaf" +
   " (een verzameling punten waarvan sommigen verbonden zijn). Denk bijvoorbeeld aan het vinden van de kortste route" +
   " tussen twee steden. Het slimme van Dijkstra’s algoritme is dat het niet alle mogelijke routes met elkaar" +
   " vergelijkt, maar dat het stap voor stap de kortst mogelijke afstanden tot elk punt opbouwt. In de eerste stap" +
   " kijk je naar alle punten die vanaf het beginpunt te bereiken zijn en markeer je al die punten met de afstand tot" +
   " het beginpunt. Daarna kijk je steeds vanaf het punt dat op dat moment de kortste afstand heeft tot het beginpunt" +
   " naar alle punten die je vanaf daar kunt bereiken. Als je een buurpunt via een nieuwe verbinding op een snellere" +
   " manier kunt bereiken, schrijf je de nieuwe, kortere afstand tot het beginpunt bij zo’n punt. Zo ga je steeds een" +
   " stukje verder tot je alle punten hebt gehad en je de kortste route tot het eindpunt hebt gevonden."
 def minNumLinesWrap(text: String, LineWidth: Int) {
   val tokenizer = new StringTokenizer(text)
   var SpaceLeft = LineWidth
   while (tokenizer.hasMoreTokens) {
     val word: String = tokenizer.nextToken
     if ((word.length + spaceWidth) > SpaceLeft) {
       print("\n" + word + " ")
       SpaceLeft = LineWidth - word.length
     } else {
       print(word + " ")
       SpaceLeft -= (word.length + spaceWidth)
     }
   }
 }
 letsWrap(ewd)
 letsWrap(ewd, 120)

} // 44 lines</lang>

Output:
Wrapped at: 80

................................................................................ Vijftig jaar geleden publiceerde Edsger Dijkstra zijn kortstepadalgoritme. Daarom een kleine ode aan de in 2002 overleden Dijkstra, iemand waar we als Nederlanders best wat trotser op mogen zijn. Dijkstra was een van de eerste programmeurs van Nederland. Toen hij in 1957 trouwde, werd het beroep computerprogrammeur door de burgerlijke stand nog niet erkend en uiteindelijk gaf hij maar `theoretische natuurkundige’ op. Zijn beroemdste resultaat is het kortstepadalgoritme, dat de kortste verbinding vindt tussen twee knopen in een graaf (een verzameling punten waarvan sommigen verbonden zijn). Denk bijvoorbeeld aan het vinden van de kortste route tussen twee steden. Het slimme van Dijkstra’s algoritme is dat het niet alle mogelijke routes met elkaar vergelijkt, maar dat het stap voor stap de kortst mogelijke afstanden tot elk punt opbouwt. In de eerste stap kijk je naar alle punten die vanaf het beginpunt te bereiken zijn en markeer je al die punten met de afstand tot het beginpunt. Daarna kijk je steeds vanaf het punt dat op dat moment de kortste afstand heeft tot het beginpunt naar alle punten die je vanaf daar kunt bereiken. Als je een buurpunt via een nieuwe verbinding op een snellere manier kunt bereiken, schrijf je de nieuwe, kortere afstand tot het beginpunt bij zo’n punt. Zo ga je steeds een stukje verder tot je alle punten hebt gehad en je de kortste route tot het eindpunt hebt gevonden.

Wrapped at: 120 ........................................................................................................................ Vijftig jaar geleden publiceerde Edsger Dijkstra zijn kortstepadalgoritme. Daarom een kleine ode aan de in 2002 overleden Dijkstra, iemand waar we als Nederlanders best wat trotser op mogen zijn. Dijkstra was een van de eerste programmeurs van Nederland. Toen hij in 1957 trouwde, werd het beroep computerprogrammeur door de burgerlijke stand nog niet erkend en uiteindelijk gaf hij maar `theoretische natuurkundige’ op. Zijn beroemdste resultaat is het kortstepadalgoritme, dat de kortste verbinding vindt tussen twee knopen in een graaf (een verzameling punten waarvan sommigen verbonden zijn). Denk bijvoorbeeld aan het vinden van de kortste route tussen twee steden. Het slimme van Dijkstra’s algoritme is dat het niet alle mogelijke routes met elkaar vergelijkt, maar dat het stap voor stap de kortst mogelijke afstanden tot elk punt opbouwt. In de eerste stap kijk je naar alle punten die vanaf het beginpunt te bereiken zijn en markeer je al die punten met de afstand tot het beginpunt. Daarna kijk je steeds vanaf het punt dat op dat moment de kortste afstand heeft tot het beginpunt naar alle punten die je vanaf daar kunt bereiken. Als je een buurpunt via een nieuwe verbinding op een snellere manier kunt bereiken, schrijf je de nieuwe, kortere afstand tot het beginpunt bij zo’n punt. Zo ga je steeds een stukje verder tot je alle punten hebt gehad en je de kortste route tot het eindpunt hebt gevonden.

Process finished with exit code 0

Scheme

The simple, greedy algorithm:

<lang scheme> (import (scheme base)

       (scheme write)
       (only (srfi 13) string-join string-tokenize))
word wrap, using greedy algorithm with minimum lines

(define (simple-word-wrap str width)

 (let loop ((words (string-tokenize str))
            (line-length 0)
            (line '())
            (lines '()))
   (cond ((null? words)
          (reverse (cons (reverse line) lines)))
         ((> (+ line-length (string-length (car words)))
             width)
          (if (null? line) 
            (loop (cdr words) ; case where word exceeds line length
                  0
                  '()
                  (cons (list (car words)) lines))
            (loop words ; word must go to next line, so finish current line
                  0
                  '()
                  (cons (reverse line) lines))))
         (else
           (loop (cdr words) ; else, add word to current line
                 (+ 1 line-length (string-length (car words)))
                 (cons (car words) line)
                 lines)))))
run examples - text from RnRS report

(define *text* "Programming languages should be designed not by piling feature on top of feature, but by removing the weaknesses and restrictions that make additional features appear necessary. Scheme demonstrates that a very small number of rules for forming expressions, with no restrictions on how they are composed, suffice to form a practical and efficient programming language that is flexible enough to support most of the major programming paradigms in use today.")

(define (show-para algorithm width)

 (display (make-string width #\-)) (newline)
 (for-each (lambda (line) (display (string-join line " ")) (newline))
           (algorithm *text* width)))

(show-para simple-word-wrap 50) (show-para simple-word-wrap 60) </lang>

Output:

(The line of hyphens shows the target width.)

--------------------------------------------------
Programming languages should be designed not by
piling feature on top of feature, but by removing
the weaknesses and restrictions that make
additional features appear necessary. Scheme
demonstrates that a very small number of rules for
forming expressions, with no restrictions on how
they are composed, suffice to form a practical and
efficient programming language that is flexible
enough to support most of the major programming
paradigms in use today.
------------------------------------------------------------
Programming languages should be designed not by piling
feature on top of feature, but by removing the weaknesses
and restrictions that make additional features appear
necessary. Scheme demonstrates that a very small number of
rules for forming expressions, with no restrictions on how
they are composed, suffice to form a practical and efficient
programming language that is flexible enough to support most
of the major programming paradigms in use today.

Seed7

<lang seed7>$ include "seed7_05.s7i";

const func string: wrap (in string: aText, in integer: lineWidth) is func

 result
   var string: wrapped is "";
 local
   var array string: words is 0 times "";
   var string: word is "";
   var integer: spaceLeft is 0;
 begin
   words := split(aText, " ");
   if length(words) <> 0 then
     wrapped := words[1];
     words := words[2 ..];
     spaceLeft := lineWidth - length(wrapped);
     for word range words do
       if length(word) + 1 > spaceLeft then
         wrapped &:= "\n" & word;
         spaceLeft := lineWidth - length(word);
       else
         wrapped &:= " " & word;
         spaceLeft -:= 1 + length(word);
       end if;
     end for;
   end if;
 end func;

const proc: main is func

 local
   const string: frog is "In olden times when wishing still helped one, there lived \
       \a king whose daughters were all beautiful, but the youngest was so beautiful \
       \that the sun itself, which has seen so much, was astonished whenever it \
       \shone in her face. Close by the king's castle lay a great dark forest, and \
       \under an old lime-tree in the forest was a well, and when the day was very \
       \warm, the king's child went out into the forest and sat down by the side of \
       \the cool fountain, and when she was bored she took a golden ball, and threw \
       \it up on high and caught it, and this ball was her favorite plaything.";
   var integer: width is 0;
 begin 
   for width range [] (72, 80) do
     writeln("Wrapped at " <& width <& ":");
     writeln(wrap(frog, width));
   end for;

end func;</lang>

Output:
Wrapped at 72:

In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.

Wrapped at 80: In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything.

Sidef

Greedy word wrap

<lang ruby>class String {

   method wrap(width) {
       var txt = self.gsub(/\s+/, " ");
       var len = txt.len;
       var para = [];
       var i = 0;
       while (i < len) {
           var j = (i + width);
           while ((j < len) && (txt.char_at(j) != ' ')) { --j };
           para.append(txt.substr(i, j-i));
           i = j+1;
       };
       return para.join("\n");
   }

}

var text = 'aaa bb cc ddddd'; say text.wrap(6);</lang>

Output:
aaa bb
cc
ddddd

Smart word wrap

<lang ruby>class SmartWordWrap {

   has width = 80
   method prepare_words(array, depth=0, callback) {
       var root = []
       var len = 0
       var i = -1
       var limit = array.end
       while (++i <= limit) {
           len += (var word_len = array[i].len)
           if (len > width) {
               if (word_len > width) {
                   len -= word_len
                   array.splice(i, 1, array[i].split(width)...)
                   limit = array.end
                   --i; next
               }
               break
           }
           root << [
               array.first(i+1).join(' '),
               self.prepare_words(array.ft(i+1), depth+1, callback)
           ]
           if (depth.is_zero) {
               callback(root[0])
               root = []
           }
           break if (++len >= width)
       }
       root
   }
   method combine(root, path, callback) {
       var key = path.shift
       path.each { |value|
           root << key
           if (value.is_empty) {
               callback(root)
           }
           else {
               value.each { |item|
                   self.combine(root, item, callback)
               }
           }
           root.pop
       }
   }
   method wrap(text, width) {
       self.width = width
       var words = (text.kind_of(Array) ? text : text.words)
       var best = Hash(
           score => Inf,
           value => [],
       )
       self.prepare_words(words, callback: { |path|
           self.combine([], path, { |combination|
               var score = 0
               combination.ft(0, -2).each { |line|
                   score += (width - line.len -> sqr)
               }
               if (score < best{:score}) {
                   best{:score} = score
                   best{:value} = []+combination
               }
           })
       })
       best{:value}.join("\n")
   }

}   var sww = SmartWordWrap();   var words = %w(aaa bb cc ddddd); var wrapped = sww.wrap(words, 6);   say wrapped;</lang>

Output:
aaa
bb cc
ddddd

Tcl

Using a simple greedy algorithm to wrap the same text as used in the Go solution. Note that it assumes that the line length is longer than the longest word length. <lang tcl>package require Tcl 8.5

proc wrapParagraph {n text} {

   regsub -all {\s+} [string trim $text] " " text
   set RE "^(.{1,$n})(?:\\s+(.*))?$"
   for {set result ""} {[regexp $RE $text -> line text]} {} {

append result $line "\n"

   }
   return [string trimright $result "\n"]

}

set txt \ "In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything."

puts "[string repeat - 80]" puts [wrapParagraph 80 $txt] puts "[string repeat - 72]" puts [wrapParagraph 72 $txt]</lang>

Output:
--------------------------------------------------------------------------------
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face. Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.
------------------------------------------------------------------------
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
sun itself, which has seen so much, was astonished whenever it shone in
her face. Close by the king's castle lay a great dark forest, and under
an old lime-tree in the forest was a well, and when the day was very
warm, the king's child went out into the forest and sat down by the side
of the cool fountain, and when she was bored she took a golden ball, and
threw it up on high and caught it, and this ball was her favorite
plaything.

TPP

The text presentation program automatically provides word wrap:

<lang tpp> The kings youngest daughter was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face.</lang>

TUSCRIPT

<lang tuscript> $$ MODE TUSCRIPT text="In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old lime-tree in the forest was a well, and when the day was very warm, the king's child went out into the forest and sat down by the side of the cool fountain, and when she was bored she took a golden ball, and threw it up on high and caught it, and this ball was her favorite plaything."

ERROR/STOP CREATE ("text",seq-E,-std-)

length=80 line=REPEAT ("-",length) FILE "text" = line firstline=nextlines="" wrappedtext=FORMAT(text,length,firstline,nextlines) FILE "text" = wrappedtext

length=72 line=REPEAT ("-",length) FILE "text" = line firstline=CONCAT ("Length ",length,": ") wrappedtext=FORMAT(text,length,firstline,nextlines) FILE "text" = wrappedtext </lang>

Output:
--------------------------------------------------------------------------------
In olden times when wishing still helped one, there lived a king whose daughters
were all beautiful, but the youngest was so beautiful that the sun itself, which
has seen so much, was astonished whenever it shone in her face.  Close by the
king's castle lay a great dark forest, and under an old lime-tree in the forest
was a well, and when the day was very warm, the king's child went out into the
forest and sat down by the side of the cool fountain, and when she was bored she
took a golden ball, and threw it up on high and caught it, and this ball was her
favorite plaything.
------------------------------------------------------------------------
Length 72: In olden times when wishing still helped one, there lived a
king whose daughters were all beautiful, but the youngest was so
beautiful that the sun itself, which has seen so much, was astonished
whenever it shone in her face.  Close by the king's castle lay a great
dark forest, and under an old lime-tree in the forest was a well, and
when the day was very warm, the king's child went out into the forest
and sat down by the side of the cool fountain, and when she was bored
she took a golden ball, and threw it up on high and caught it, and this
ball was her favorite plaything.          

VBScript

<lang vb> column = 60 text = "In olden times when wishing still helped one, there lived a king " &_ "whose daughters were all beautiful, but the youngest was so beautiful "&_ "that the sun itself, which has seen so much, was astonished whenever "&_ "it shone-in-her-face. Close-by-the-king's castle lay a great dark "&_ "forest, and under an old lime-tree in the forest was a well, and when "&_ "the day was very warm, the king's child went out into the forest and "&_ "sat down by the side of the cool-fountain, and when she was bored she "&_ "took a golden ball, and threw it up on high and caught it, and this "&_ "ball was her favorite plaything."

Call wordwrap(text,column)

Sub wordwrap(s,n) word = Split(s," ") row = "" For i = 0 To UBound(word) If Len(row) = 0 Then row = row & word(i) ElseIf Len(row & " " & word(i)) <= n Then row = row & " " & word(i) Else WScript.StdOut.WriteLine row row = word(i) End If Next If Len(row) > 0 Then WScript.StdOut.WriteLine row End If End Sub </lang>

Output:

Wrapped at 60.

In olden times when wishing still helped one, there lived a
king whose daughters were all beautiful, but the youngest
was so beautiful that the sun itself, which has seen so
much, was astonished whenever it shone-in-her-face. 
Close-by-the-king's castle lay a great dark forest, and
under an old lime-tree in the forest was a well, and when
the day was very warm, the king's child went out into the
forest and sat down by the side of the cool-fountain, and
when she was bored she took a golden ball, and threw it up
on high and caught it, and this ball was her favorite
plaything.

Yabasic

<lang Yabasic>t$ = "In olden times when wishing still helped one, there lived a king " t$ = t$ + "whose daughters were all beautiful, but the youngest was so beautiful " t$ = t$ + "that the sun itself, which has seen so much, was astonished whenever " t$ = t$ + "it shone in her face.\n\n" t$ = t$ + t$

t$ = trim$(t$)

input "Width: " width // user specifies width

dim p$(1)

d$ = " .,\n"

n = words(t$, p$(), d$)

for i = 1 to n

 if p$(i) = "\n" or len(docOut$) + len(p$(i)) > width then
   print docOut$
   docOut$ = ""
 end if
 if p$(i) <> "\n" docOut$ = docOut$ + p$(i)

next i print docOut$

sub words(w$, p$(), d$) local n, i, p

n = split(w$, p$(), d$) p = 1

for i = 1 to n p$(i) = p$(i) + mid$(w$, p + len(p$(i)), 1) p = p + len(p$(i)) next i return n end sub</lang>

Translation of: Run BASIC

<lang Yabasic>t$ = "In olden times when wishing still helped one, there lived a king " t$ = t$ + "whose daughters were all beautiful, but the youngest was so beautiful " t$ = t$ + "that the sun itself, which has seen so much, was astonished whenever " t$ = t$ + "it shone in her face."

wrap$ = " style='white-space: pre-wrap;white-space: -moz-pre-wrap;white-space: -pre-wrap;white-space: -o-pre-wrap;word-wrap: break-word'"

f = open("WordWrap.html", "w")

print #f "

<tr" + wrap$ +" valign=top>" print #f "
" + t$ + "" + t$ + "

"

close #f

void = system("explorer WordWrap.html")</lang>

zkl

This is a greedy algorithm for mono spaced text with ragged right. In addition, it can look at the first two lines to do "smart indenting". It handles multiple paragraphs and a variety of input sources. <lang zkl>fcn formatText(text, // text can be String,Data,File, -->Data

      length=72, calcIndents=True){
  sink:=Data();
  getIndents:='wrap(w){	// look at first two lines to indent paragraph
     reg lines=L(), len=0, prefix="", one=True;
     do(2){

if(w._next()){ lines.append(line:=w.value); word:=line.split(Void,1)[0,1]; // get first word, if line !blank if(word){ p:=line[0,line.find(word[0]]); if(one){ sink.write(p); len=p.len(); one=False; } else prefix=p; } }

     }
     w.push(lines.xplode());  // put first two lines back to be formated
     return(len,prefix);
  };
  reg len=0, prefix="", w=text.walker(1);	// lines
  if(calcIndents) len,prefix=getIndents(w);
  foreach line in (w){
     if(not line.strip()){ // blank line

sink.write("\n",line); // blank line redux if(calcIndents) len,prefix=getIndents(w); else len=0; // restart formating

     }else

len=line.split().reduce('wrap(len,word){ n:=word.len(); if(len==0) { sink.write(word); return(n); } nn:=n+1+len; if(nn<=length) { sink.write(" ",word); return(nn); } sink.write("\n",prefix,word); return(prefix.len()+word.len()); },len);

  }
  sink

}</lang> <lang zkl>formatText(File("frog.txt")).text.println();</lang>

Output:
In olden times when wishing still helped one, there lived a king whose
daughters were all beautiful, but the youngest was so beautiful that the
...

Putting a bit of spit shine on the above and editing the source text to look like:

    In olden 
times ...

<lang zkl>[1..].zipWith("%2d: %s".fmt,formatText(File("frog.txt")).walker(1)) .pump(String).println();</lang>

Output:
 1:      In olden times when wishing still helped one, there lived a king
 2: whose daughters were all beautiful, but the youngest was so beautiful
...
 9: favorite plaything.

<lang zkl>formatText("this\n is a test foo bar\n\ngreen eggs and spam",10).text.println();</lang>

Output:
this is a
   test
   foo bar

green eggs
and spam