Word wrap: Difference between revisions

<langsyntaxhighlight Adalang="ada">generic

end Word_Wrap;</langsyntaxhighlight>

<langsyntaxhighlight Adalang="ada">package body Word_Wrap is

end Word_Wrap;</langsyntaxhighlight>

<langsyntaxhighlight Adalang="ada">with Ada.Text_IO, Word_Wrap, Ada.Strings.Unbounded, Ada.Command_Line;

end Wrap;</langsyntaxhighlight>

Output,{{out}} set to 72 lines (with input picked by cut-and-paste from the task description):

<langsyntaxhighlight lang="awk">function wordwrap_paragraph(p)

}</langsyntaxhighlight>

"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.

#define PENALTY_LONG 100

#define PENALTY_SHORT 1

const char *s;

int len;

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 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;

here somewhere */

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;

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;

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 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;

}</langsyntaxhighlight>

<lang cpp>#include <iostreamstdio.h>

#include <sstreamstring.h>

if (words*p >>== word' ') {

last_space = wrapped << wordp;

an old lime -tree in the forest was a well, and when the day was very

<langsyntaxhighlight lang="csharp">namespace RosettaCode.WordWrap

}</langsyntaxhighlight>

<langsyntaxhighlight lang="d">void main() {

}</langsyntaxhighlight>

<langsyntaxhighlight lang="d">import std.algorithm;

}</langsyntaxhighlight>

<langsyntaxhighlight lang="fsharp">open System

0</langsyntaxhighlight>

<langsyntaxhighlight lang="forth">\ wrap text

bye</langsyntaxhighlight>

<langsyntaxhighlight lang="go">package main

}</langsyntaxhighlight>

++ , "theit dayshone wasin veryher warm,face. Close by the king's childcastle wentlay out into thea forestgreat anddark"

++ , "satforest, downand byunder thean sideold oflime-tree in the coolforest fountainwas a well, and when she was bored she"

++ , "tookthe aday goldenwas ballvery warm, andthe threwking's itchild upwent onout highinto andthe caught it,forest and this"

wordwrap maxlen = (wrap_ 0) . words where

wrap_ pos_ [] = (w:ws)"\n"

| pos + lw + 1 >| maxlenpos = '\n':wrap_= 0 (= w:ws ++ wrap_ (pos + lw) ws

| otherwise = " " ++ w| ++ wrap_ (pos + lw + 1) > maxlen = '\n' : wrap_ 0 (w : ws)

'''Solution''':<langsyntaxhighlight lang="j">ww =: 75&$: : wrap

edges =: (_1 + ] #~ 1 ,~ 2 >/\ |) [: +/\ #;.2</langsyntaxhighlight>

'''Example''':<langsyntaxhighlight 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.'

were created equal.</langsyntaxhighlight>

<langsyntaxhighlight lang="java">

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);

<langsyntaxhighlight lang="ocaml">#load "str.cma"

print_endline (Buffer.contents buf)</langsyntaxhighlight>

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

wrap(King, 50)</langsyntaxhighlight>

<langsyntaxhighlight lang="perl">my $s = "In olden times when wishing still helped one, there lived a king

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