Loops/N plus one half

Loops/N plus one half
You are encouraged to solve this task according to the task description, using any language you may know.

Quite often one needs loops which, in the last iteration, execute only part of the loop body.

Goal

Demonstrate the best way to do this.

Task

Write a loop which writes the comma-separated list

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

using separate output statements for the number and the comma from within the body of the loop.

Related tasks

• Loop over multiple arrays simultaneously
• Loops/Break
• Loops/Continue
• Loops/Do-while
• Loops/Downward for
• Loops/For
• Loops/For with a specified step
• Loops/Foreach
• Loops/Increment loop index within loop body
• Loops/Infinite
• Loops/N plus one half
• Loops/Nested
• Loops/While
• Loops/with multiple ranges
• Loops/Wrong ranges

11l

L(i) 1..10
   print(i, end' ‘’)
   I !L.last_iteration
      print(‘, ’, end' ‘’)

360 Assembly

*        Loops/N plus one half     13/08/2015
LOOPHALF CSECT         USING  LOOPHALF,R12
         LR     R12,R15
BEGIN    LA     R3,MVC
         SR     R5,R5
         LA     R6,1
         LA     R7,10
LOOPI    BXH    R5,R6,ELOOPI       for i=1 to 10
         XDECO  R5,XDEC
         MVC    0(4,R3),XDEC+8
         LA     R3,4(R3)
         CH     R5,=H'10'
         BNL    NEXTI
         MVC    0(2,R3),=C', '
         LA     R3,2(R3)
NEXTI    B      LOOPI              next i
ELOOPI   XPRNT  MVC,80
         XR     R15,R15
         BR     R14
MVC      DC     CL80' '
XDEC     DS     CL12
         YREGS  
         END    LOOPHALF

Output:

   1,    2,    3,    4,    5,    6,    7,    8,    9,   10

68000 Assembly

Sega Genesis cartridge header and hardware print routines/bitmap font are omitted here but do work as intended.

	moveq #0,d0
	move.w #1,d1		;ABCD can't use an immediate operand
	move.w #10-1,d2
loop:
	abcd d1,d0
	move.l d0,-(sp)
		jsr printhex
	move.l (sp)+,d0
	cmp.b #$10,d0		;we use hex 10 since this is binary-coded decimal
	beq exitEarly
	move.l d0,-(sp)
		move.b #',',D0	;PrintChar uses D0 as input
		jsr PrintChar
		move.b #' ',D0  
		jsr PrintChar
	move.l (sp)+,d0	
	DBRA d2,loop
	
exitEarly:
	
	
	; include "X:\SrcGEN\testModule.asm"
	
	jmp *

Output:

01, 02, 03, 04, 05, 06, 07, 08, 09, 10

8086 Assembly

Since the output of the last element is different than the rest, the easiest way to accomplish this is by "breaking out" of the loop with a comparison to 10.

    .model small
    .stack 1024

    .data   ;no data needed
     
    .code
	
start:
	mov ax,0000h	
	mov cx,0FFFFh	;this value doesn't matter as long as it's greater than decimal 10.
	
repeatPrinting:
	add ax,1 ;it was easier to start at zero and add here than to start at 1 and add after printing.
	aaa	 ;ascii adjust for addition, corrects 0009h+1 from 000Ah to 0100h
	call PrintBCD_IgnoreLeadingZeroes
	cmp ax,0100h		;does AX = BCD 10?
	je exitLoopEarly	;if so, we're done now. Don't finish the loop.
	push ax
		mov dl,","       ;print a comma
		mov ah,02h
		int 21h        
		
		mov dl,20h	;print a blank space
		mov ah,02h
		int 21h
	pop ax
	loop repeatPrinting
exitLoopEarly:
	mov ax,4C00h
	int 21h			;return to DOS

PrintBCD_IgnoreLeadingZeroes:
	push ax
		cmp ah,0
		jz skipLeadingZero
			or ah,30h                      ;converts a binary-coded-decimal value to an ASCII numeral
			push dx
			push ax
				mov al,ah
				mov ah,0Eh
				int 10h			;prints AL to screeen
			pop ax
			pop dx
skipLeadingZero:
		or al,30h
		push dx
		push ax
			mov ah,0Eh
			int 10h				;prints AL to screen
		pop ax
		pop dx
	pop ax
	ret
        end start ;EOF

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

AArch64 Assembly

Works with: as version Raspberry Pi 3B version Buster 64 bits

/* ARM assembly AARCH64 Raspberry PI 3B */
/*  program loopnplusone64.s   */
 
/*******************************************/
/* Constantes file                         */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesARM64.inc"
/*********************************/
/* Initialized data              */
/*********************************/
.data
szMessResult:      .asciz "@"             // message result
szMessComma:       .asciz ", "
szCarriageReturn:  .asciz "\n"
/*********************************/
/* UnInitialized data            */
/*********************************/
.bss 
sZoneConv:              .skip 24
/*********************************/
/*  code section                 */
/*********************************/
.text
.global main 
main:                                     // entry of program 
    mov x20,1                             // loop counter
1:                                        // begin loop 
    mov x0,x20
    ldr x1,qAdrsZoneConv                  // display value
    bl conversion10                       // decimal conversion
    ldr x0,qAdrszMessResult
    ldr x1,qAdrsZoneConv                  // display value
    bl strInsertAtCharInc                 // insert result at @ character
    bl affichageMess                      // display message
    ldr x0,qAdrszMessComma
    bl affichageMess                      // display comma
    add x20,x20,1                             // increment counter
    cmp x20,10                            // end ?
    blt 1b                                // no ->begin loop one
    mov x0,x20
    ldr x1,qAdrsZoneConv                  // display value
    bl conversion10                       // decimal conversion
    ldr x0,qAdrszMessResult
    ldr x1,qAdrsZoneConv                  // display value
    bl strInsertAtCharInc                 // insert result at @ character
    bl affichageMess                      // display message
    ldr x0,qAdrszCarriageReturn
    bl affichageMess                      // display return line
 
100:                                      // standard end of the program 
    mov x0,0                              // return code
    mov x8,EXIT                           // request to exit program
    svc 0                                 // perform the system call
 
qAdrsZoneConv:            .quad sZoneConv
qAdrszMessResult:         .quad szMessResult
qAdrszMessComma:          .quad szMessComma
qAdrszCarriageReturn:     .quad szCarriageReturn

/********************************************************/
/*        File Include fonctions                        */
/********************************************************/
/* for this file see task include a file in language AArch64 assembly */
.include "../includeARM64.inc"

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

ACL2

ACL2 does not have loops, but this is close:

(defun print-list (xs)
   (progn$ (cw "~x0" (first xs))
           (if (endp (rest xs))
               (cw (coerce '(#\Newline) 'string))
               (progn$ (cw ", ")
                       (print-list (rest xs))))))

Action!

PROC Main()
  BYTE i=[1]
  
  DO
    PrintB(i)
    IF i=10 THEN
      EXIT
    FI
    Print(", ")
    i==+1
  OD
RETURN

Output:

Screenshot from Atari 8-bit computer

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Ada

with Ada.Text_IO;

procedure LoopsAndHalf is 
begin
  for i in 1 .. 10 loop
    Ada.Text_IO.put (i'Img);
    exit when i = 10;
    Ada.Text_IO.put (",");
  end loop;
  Ada.Text_IO.new_line;
end LoopsAndHalf;

Aime

integer i;

i = 0;
while (1) {
    i += 1;
    o_integer(i);
    if (i == 10) {
        break;
    }
    o_text(", ");
}
o_text("\n");

ALGOL 60

Works with: ALGOL 60 version OS/360

'BEGIN'
  'COMMENT' Loops N plus one half - Algol60 - 20/06/2018;
  'INTEGER' I;
  'FOR' I:=1 'STEP' 1 'UNTIL' 10 'DO' 'BEGIN'
    OUTINTEGER(1,I);
    'IF' I 'NOTEQUAL' 10 'THEN' OUTSTRING(1,'(', ')')
  'END'
'END'

Output:

         +1  ,          +2  ,          +3  ,          +4  ,          +5  ,          +6  ,          +7  ,          +8  ,         +9  ,         +10

ALGOL 68

Works with: ALGOL 68 version Standard - no extensions to language used

Works with: ALGOL 68G version Any - tested with release mk15-0.8b.fc9.i386

Works with: ELLA ALGOL 68 version Any (with appropriate job cards) - tested with release 1.8.8d.fc9.i386

There are three common ways of achieving n+½ loops:

FOR i WHILE print(whole(i, -2)); # WHILE # i < 10 DO print(", ") OD; print(new line)

FOR i TO 10 DO print(whole(i, -2)); IF i < 10 THEN print(", ") FI OD; print(new line)

FOR i DO print(whole(i, -2)); IF i >= 10 THEN GO TO done FI; print(", ") OD; done: print(new line)

Output for all cases above:

 1,  2,  3,  4,  5,  6,  7,  8,  9, 10

ALGOL W

begin
    integer i;
    i := 0;
    while
        begin
           i := i + 1;
           writeon( i );
           i < 10
        end
    do
    begin
       writeon( "," )
    end
end.

AmigaE

PROC main()
  DEF i
  FOR i := 1 TO 10
    WriteF('\d', i)
    EXIT i = 10
    WriteF(', ')
  ENDFOR
ENDPROC

ARM Assembly

Works with: as version Raspberry Pi

/* ARM assembly Raspberry PI  */
/*  program loopnplusone.s   */

/* Constantes    */
.equ STDOUT, 1     @ Linux output console
.equ EXIT,   1     @ Linux syscall
.equ WRITE,  4     @ Linux syscall

/*********************************/
/* Initialized data              */
/*********************************/
.data
szMessResult:      .ascii ""                    @ message result
sMessValeur:       .fill 11, 1, ' '
szMessComma:       .asciz ","
szCarriageReturn:  .asciz "\n"
/*********************************/
/* UnInitialized data            */
/*********************************/
.bss 
/*********************************/
/*  code section                 */
/*********************************/
.text
.global main 
main:                                       @ entry of program 
    mov r4,#1                               @ loop counter
1:                                          @ begin loop 
    mov r0,r4
    ldr r1,iAdrsMessValeur                  @ display value
    bl conversion10                         @ decimal conversion
    ldr r0,iAdrszMessResult
    bl affichageMess                        @ display message
    ldr r0,iAdrszMessComma
    bl affichageMess                        @ display comma
    add r4,#1                               @ increment counter
    cmp r4,#10                              @ end ?
    blt 1b                                  @ no ->begin loop one
    mov r0,r4
    ldr r1,iAdrsMessValeur                  @ display value
    bl conversion10                         @ decimal conversion
    ldr r0,iAdrszMessResult
    bl affichageMess                        @ display message
    ldr r0,iAdrszCarriageReturn
    bl affichageMess                        @ display return line

100:                                        @ standard end of the program 
    mov r0, #0                              @ return code
    mov r7, #EXIT                           @ request to exit program
    svc #0                                  @ perform the system call

iAdrsMessValeur:          .int sMessValeur
iAdrszMessResult:         .int szMessResult
iAdrszMessComma:          .int szMessComma
iAdrszCarriageReturn:     .int szCarriageReturn
/******************************************************************/
/*     display text with size calculation                         */ 
/******************************************************************/
/* r0 contains the address of the message */
affichageMess:
    push {r0,r1,r2,r7,lr}                   @ save  registres
    mov r2,#0                               @ counter length 
1:                                          @ loop length calculation 
    ldrb r1,[r0,r2]                         @ read octet start position + index 
    cmp r1,#0                               @ if 0 its over 
    addne r2,r2,#1                          @ else add 1 in the length 
    bne 1b                                  @ and loop 
                                            @ so here r2 contains the length of the message 
    mov r1,r0                               @ address message in r1 
    mov r0,#STDOUT                          @ code to write to the standard output Linux 
    mov r7, #WRITE                          @ code call system "write" 
    svc #0                                  @ call systeme 
    pop {r0,r1,r2,r7,lr}                    @ restaur registers */ 
    bx lr                                   @ return  
/******************************************************************/
/*     Converting a register to a decimal                                 */ 
/******************************************************************/
/* r0 contains value and r1 address area   */
.equ LGZONECAL,   10
conversion10:
    push {r1-r4,lr}                         @ save registers 
    mov r3,r1
    mov r2,#LGZONECAL

1:                                          @ start loop
    bl divisionpar10                        @ r0 <- dividende. quotient ->r0 reste -> r1
    add r1,#48                              @ digit
    strb r1,[r3,r2]                         @ store digit on area
    sub r2,#1                               @ previous position
    cmp r0,#0                               @ stop if quotient = 0 
    bne 1b                                  @ else loop
                                            @ end replaces digit in front of area
    mov r4,#0
2:
    ldrb r1,[r3,r2] 
    strb r1,[r3,r4]                         @ store in area begin
    add r4,#1
    add r2,#1                               @ previous position
    cmp r2,#LGZONECAL                       @ end
    ble 2b                                  @ loop
    mov r1,#0                               @ final zero 
    strb r1,[r3,r4]
100:
    pop {r1-r4,lr}                          @ restaur registres 
    bx lr                                   @return
/***************************************************/
/*   division par 10   signé                       */
/* Thanks to http://thinkingeek.com/arm-assembler-raspberry-pi/*  
/* and   http://www.hackersdelight.org/            */
/***************************************************/
/* r0 dividende   */
/* r0 quotient */	
/* r1 remainder  */
divisionpar10:	
  /* r0 contains the argument to be divided by 10 */
    push {r2-r4}                           @ save registers  */
    mov r4,r0  
    mov r3,#0x6667                         @ r3 <- magic_number  lower
    movt r3,#0x6666                        @ r3 <- magic_number  upper
    smull r1, r2, r3, r0                   @ r1 <- Lower32Bits(r1*r0). r2 <- Upper32Bits(r1*r0) 
    mov r2, r2, ASR #2                     @ r2 <- r2 >> 2
    mov r1, r0, LSR #31                    @ r1 <- r0 >> 31
    add r0, r2, r1                         @ r0 <- r2 + r1 
    add r2,r0,r0, lsl #2                   @ r2 <- r0 * 5 
    sub r1,r4,r2, lsl #1                   @ r1 <- r4 - (r2 * 2)  = r4 - (r0 * 10)
    pop {r2-r4}
    bx lr                                  @ return

ArnoldC

IT'S SHOWTIME
HEY CHRISTMAS TREE n
YOU SET US UP @NO PROBLEMO
HEY CHRISTMAS TREE lessThanTen
YOU SET US UP @NO PROBLEMO
STICK AROUND lessThanTen
TALK TO THE HAND n
GET TO THE CHOPPER lessThanTen
HERE IS MY INVITATION 10
LET OFF SOME STEAM BENNET n
ENOUGH TALK
BECAUSE I'M GOING TO SAY PLEASE lessThanTen
TALK TO THE HAND ", "
YOU HAVE NO RESPECT FOR LOGIC
GET TO THE CHOPPER n
HERE IS MY INVITATION n
GET UP @NO PROBLEMO
ENOUGH TALK
CHILL
YOU HAVE BEEN TERMINATED

Arturo

print join.with:", " map 1..10 => [to :string]

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Asymptote

for(int i = 1; i <= 10; ++i) {
  write(i, suffix=none); 
  if(i < 10)  write(", ", suffix=none);
}

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

AutoHotkey

Loop, 9                ; loop 9 times
{
  output .= A_Index    ; append the index of the current loop to the output var
  If (A_Index <> 9)    ; if it isn't the 9th iteration of the loop
    output .= ", "     ; append ", " to the output var
}
MsgBox, %output%

AutoIt

#cs ----------------------------------------------------------------------------

 AutoIt Version: 3.3.8.1
 Author:         Alexander Alvonellos

 Script Function:
	Output a comma separated list from 1 to 10, and on the tenth iteration of the
	output loop, only perform half of the loop.

#ce ----------------------------------------------------------------------------

Func doLoopIterative()
		Dim $list = ""
		For $i = 1 To 10 Step 1
			$list = $list & $i
			If($i = 10) Then ExitLoop
			$list = $list & ", "
		Next
		return $list & @CRLF
EndFunc

Func main()
	ConsoleWrite(doLoopIterative())
EndFunc

main()

AWK

One-liner:

$ awk 'BEGIN{for(i=1;i<=10;i++){printf i;if(i<10)printf ", "};print}'

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Readable version:

BEGIN {
  n=10
  for(i=1;i<=n;i++) {
    printf i; 
    if(i<n) printf ", "
  }
  print
}

Same output.

Axe

For(I,1,10)
 Disp I▶Dec
 If I=10
  Disp i
 Else
  Disp ","
 End
End

BASIC

Works with: FreeBASIC

Works with: QBasic version 1.1

Works with: QuickBasic version 4.5

Works with: RapidQ

DIM i AS Integer

FOR i=1 TO 10
    PRINT USING "##"; i;
    IF i=10 THEN EXIT FOR
    PRINT ", ";
NEXT i

Applesoft BASIC

Works with: Commodore BASIC

The ZX Spectrum Basic code will work just fine in Applesoft BASIC. The following is a more structured approach which avoids the use of GOTO.

10 FOR I = 1 TO 10
20     PRINT I;
30     IF I < 10 THEN PRINT ", "; : NEXT I

ASIC

If equality checking affect the efficiency or if the last value were treated in different manner, one can extract the last iteration.

ASIC prints integer numbers as six-char strings. If shorter ones are needed, one can use the STR$ and LTRIM$ functions.

REM Loops/N plus one half
FOR I = 1 TO 9
  PRINT I; 
  PRINT ",";
NEXT I
PRINT 10
END

Output:

     1,     2,     3,     4,     5,     6,     7,     8,     9,    10

Basic09

PROCEDURE nAndAHalf
   DIM i:INTEGER
   FOR i:=1 TO 10
      PRINT i;
   EXITIF i=10 THEN ENDEXIT
      PRINT ", ";
   NEXT i
   PRINT

BASIC256

for i = 1 to 10
	print i;
	if i < 10 then print ", ";
next i

end

BBC BASIC

      FOR i% = 1 TO 10
        PRINT ; i% ;
        IF i% <> 10 PRINT ", ";
      NEXT
      PRINT

Chipmunk Basic

Works with: Chipmunk Basic version 3.6.4

10 rem Loops/N plus one half
20 c$ = ""
30 for i = 1 to 10
40  print c$;str$(i);
50  c$ = ", "
60 next i

FBSL

#APPTYPE CONSOLE
For Dim i = 1 To 10
    PRINT i;
    IF i < 10 THEN PRINT ", ";
Next
PAUSE

Output

1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Press any key to continue...

FreeBASIC

' FB 1.05.0 Win64

For i As Integer = 1 To 10
  Print Str(i);
  If i < 10 Then Print ", ";
Next

Print  
Sleep

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Alternative

This makes the important point that for many loops of this kind the partial iteration could easily be the first one.

dim as string cm = ""
for i as ubyte = 1 to 10
    print cm;str(i);
    cm = ", "
next i

FutureBasic

window 1

long i, num = 10

for i = 1 to num
  print i;
  if i = num then break
  print @", ";
next i

HandleEvents

Output:

 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Gambas

Click this link to run this code

Public Sub Main()
Dim siLoop As Short

For siLoop = 1 To 10
  Print siLoop;
  If siLoop <> 10 Then Print ", ";
Next

End

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

GW-BASIC

10 C$ = ""
20 FOR I = 1 TO 10
30 PRINT C$;STR$(I);
40 C$=", "
50 NEXT I

IS-BASIC

100 FOR I=1 TO 10
110   PRINT I;
120   IF I=10 THEN EXIT FOR
130   PRINT ",";
140 NEXT

Liberty BASIC

Works with: Just BASIC

Keyword 'exit' allows the termination.

for i =1 to 10
    print i;
    if i =10 then exit for
    print ", ";
next i
end

Microsoft Small Basic

For i = 1 To 10
  TextWindow.Write(i)
  If i <> 10 Then
    TextWindow.Write(", ")
  EndIf
EndFor 
TextWindow.WriteLine("")

NS-HUBASIC

10 FOR I=1 TO 10
20 PRINT I;
30 IF I=10 THEN GOTO 50
40 PRINT ",";
50 NEXT

PureBasic

x=1
Repeat 
  Print(Str(x))
  x+1
  If x>10: Break: EndIf
  Print(", ")
ForEver

QBasic

Works with: QBasic version 1.1

Works with: QuickBasic version 4.5

FOR i = 1 TO 10
    PRINT USING "##"; i;
    IF i=10 THEN EXIT FOR
    PRINT ", ";
NEXT i

Run BASIC

FOR i = 1 TO 10
  PRINT cma$;i;
  cma$ = ", "
NEXT i

Sinclair ZX81 BASIC

The ZX Spectrum Basic program will work on the ZX81. Depending on the context, the programmer's intention may be clearer if we do it all with GOTOs instead of a FOR loop.

10 LET I=1
20 PRINT I;
30 IF I=10 THEN GOTO 70
40 PRINT ", ";
50 LET I=I+1
60 GOTO 20

TI-89 BASIC

There is no horizontal cursor position on the program IO screen, so we concatenate strings instead.

Local str
"" → str
For i,1,10
  str & string(i) → str
  If i < 10 Then
    str & "," → str
  EndIf
EndFor
Disp str

Tiny BASIC

Tiny BASIC does not support string concatenation so each number is on a separate line but this is at least in the spirit of the task description.

    LET I = 1
 10 IF I = 10 THEN PRINT I
    IF I < 10 THEN PRINT I,", "
    IF I = 10 THEN END
    LET I = I + 1
    GOTO 10

A solution for the dialects of Tiny BASIC that support string concatenation.

Works with: TinyBasic

10 REM Loops/N plus one half
20 LET I = 1
30 IF I = 10 THEN PRINT I
40 IF I < 10 THEN PRINT I; ", ";
50 IF I = 10 THEN END
60 LET I = I + 1
70 GOTO 30

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

True BASIC

Works with: QBasic

LET cm$ = ""
FOR i = 1 to 10
    PRINT cm$; str$(i);
    LET cm$ = ", "
NEXT i
END

VBA

Public Sub WriteACommaSeparatedList()
    Dim i As Integer
    Dim a(1 To 10) As String
    For i = 1 To 10
        a(i) = CStr(i)
    Next i
    Debug.Print Join(a, ", ")
End Sub

Visual Basic .NET

For i = 1 To 10
    Console.Write(i)
    If i = 10 Then Exit For
    Console.Write(", ")
Next

Wee Basic

print 1 "" ensures the end of program text is separate from the list of numbers.

print 1 ""
for numbers=1 to 10
print 1 at numbers*3-2,0 numbers
if numbers<>10
print 1 at numbers*3-1,0 ","
endif
end

XBasic

Works with: Windows XBasic

PROGRAM "n_plus_one_half"

DECLARE FUNCTION Entry()

FUNCTION Entry()
  FOR i% = 1 TO 10
    PRINT i%;
    IF i% = 10 THEN EXIT FOR
    PRINT ",";
  NEXT i%
END FUNCTION
END PROGRAM

Output:

 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

If equality checking affect the efficiency or if the last value were treated in different manner, one can extract the last iteration.

Works with: Windows XBasic

PROGRAM "n_plus_one_half"

DECLARE FUNCTION Entry()

FUNCTION Entry()
  FOR i% = 1 TO 9
    PRINT i%; ",";
  NEXT i%
  PRINT 10
END FUNCTION
END PROGRAM

Output:

 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Yabasic

for i = 1 to 10
  print i;
  if i < 10  print ", ";
next i
print  
end

ZX Spectrum Basic

Works with: Applesoft BASIC

Works with: Commodore BASIC

To terminate a loop on the ZX Spectrum, set the loop counter to a value that will exit the loop, before jumping to the NEXT statement.

10 FOR i=1 TO 10
20 PRINT i;
30 IF i=10 THEN GOTO 50
40 PRINT ", ";
50 NEXT i

bc

Works with: GNU bc

The print extension is necessary to get the required output.

while (1) {
    print ++i
    if (i == 10) {
        print "\n" 
        break
    }
    print ", "
}

Befunge

1+>::.9`#@_" ,",,

This code is a good answer. However, most Befunge implementations print a " " after using . (output number), so this program prints "1 , 2 , 3 ..." with extra spaces. A bypass for this is possible, by adding 48 and printing the ascii character, but does not work with 10::

1+>::68*+,8`#v_" ,",,
  @,,,,", 10"<

Bracmat

  1:?i
&   whl
  ' ( put$!i
    & !i+1:~>10:?i
    & put$", "
    )

C

Translation of: C++

#include <stdio.h>

int main()
{
  int i;
  for (i = 1; i <= 10; i++) {
    printf("%d", i);
    printf(i == 10 ? "\n" : ", ");
  }
  return 0;
}

C#

using System;

class Program
{
    static void Main(string[] args)
    {
        for (int i = 1; ; i++)
        {
            Console.Write(i);
            if (i == 10) break;
            Console.Write(", ");
        }
        Console.WriteLine();
    }
}

C++

#include <iostream>
 
int main()
{ 
  int i;
  for (i = 1; i<=10 ; i++){
    std::cout << i;
    if (i < 10)
     std::cout << ", ";
  }
  return 0;
}

Chapel

for i in 1..10 do
        write(i, if i % 10 > 0 then ", " else "\n")

Clojure

; Functional version
(apply str (interpose ", " (range 1 11)))

; Imperative version
(loop [n 1]
   (printf "%d" n)
   (if (< n 10)
       (do
	(print ", ")
	(recur (inc n)))))

COBOL

Works with: OpenCOBOL

       IDENTIFICATION DIVISION.
       PROGRAM-ID. Loop-N-And-Half.

       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  I    PIC 99.
       01  List PIC X(45).

       PROCEDURE DIVISION.
           PERFORM FOREVER
               *> The list to display must be built up because using
               *> DISPLAY adds an endline at the end automatically.
               STRING FUNCTION TRIM(List) " "  I  INTO List

               IF I = 10
                   EXIT PERFORM
               END-IF
               
               STRING FUNCTION TRIM(List) "," INTO List

               ADD 1 TO I
           END-PERFORM

           DISPLAY List

           GOBACK
           .

Free-form, 'List'-free version, using DISPLAY NO ADVANCING.

IDENTIFICATION DIVISION.
PROGRAM-ID. LOOP-1p5-NOADV.
DATA DIVISION.
WORKING-STORAGE SECTION.
01  I    PIC 99 VALUE 1.
01	IDISP	PIC Z9.
PROCEDURE DIVISION.
	PERFORM FOREVER
		MOVE I TO IDISP
		DISPLAY FUNCTION TRIM(IDISP) WITH NO ADVANCING
		IF I = 10
			EXIT PERFORM
		END-IF
		DISPLAY ", " WITH NO ADVANCING
		ADD 1 TO I
	END-PERFORM.
	STOP RUN.
	END-PROGRAM.

Free-form, GO TO, 88-level. Paragraphs in PROCEDURE DIVISION.

IDENTIFICATION DIVISION.
PROGRAM-ID. LOOP-1p5-NOADV-GOTO.
DATA DIVISION.
WORKING-STORAGE SECTION.
01  I	PIC 99	VALUE 1.
	88	END-LIST	VALUE 10.
01	I-OUT	PIC Z9.
PROCEDURE DIVISION.
01-LOOP.
	MOVE I TO I-OUT.
	DISPLAY FUNCTION TRIM(I-OUT) WITH NO ADVANCING.
	IF END-LIST GO TO 02-DONE.
	DISPLAY ", " WITH NO ADVANCING.
	ADD 1 TO I.
	GO TO 01-LOOP.
02-DONE.
	STOP RUN.
	END-PROGRAM.

Using 'PERFORM VARYING'

IDENTIFICATION DIVISION.
PROGRAM-ID. LOOP-1p5-NOADV-VARY.
DATA DIVISION.
WORKING-STORAGE SECTION.
01  I    	PIC 99  VALUE 1.
	88	END-LIST	VALUE 10.
01	I-OUT	PIC Z9.
PROCEDURE DIVISION.
	PERFORM WITH TEST AFTER VARYING I FROM 1 BY 1 UNTIL END-LIST 
		MOVE I TO I-OUT
		DISPLAY FUNCTION TRIM(I-OUT) WITH NO ADVANCING
		IF NOT END-LIST
			DISPLAY ", " WITH NO ADVANCING
		END-IF
	END-PERFORM.
	STOP RUN.
	END-PROGRAM.

CoffeeScript

# Loop plus half.  This code shows how to break out of a loop early
# on the last iteration.  For the contrived example, there are better
# ways to generate a comma-separated list, of course.
start = 1
end = 10
s = ''
for i in [start..end]
  # the top half of the loop executes every time
  s += i
  break if i == end
  # the bottom half of the loop is skipped for the last value
  s += ', '
console.log s

ColdFusion

With tags:

<cfloop index = "i" from = "1" to = "10">
  #i#
  <cfif i EQ 10>
    <cfbreak />
  </cfif>
  , 
</cfloop>

With script:

<cfscript>
  for( i = 1; i <= 10; i++ ) //note: the ++ notation works only on version 8 up, otherwise use i=i+1
  {
    writeOutput( i );
    
    if( i == 10 )
    {
      break;
    }
    writeOutput( ", " );
  }
</cfscript>

Common Lisp

(loop for i from 1 below 10 do 
        (princ i) (princ ", ")
        finally (princ i))

or

(loop for i from 1 upto 10 do
  (princ i)
  (if (= i 10) (return))
  (princ ", "))

but for such simple tasks we can use format's powers:

(format t "~{~a~^, ~}" (loop for i from 1 to 10 collect i))

Using DO

(do ((i 1 (incf i)))			; Initialize to 1 and increment on every loop
    ((> i 10))				; Break condition
  (princ i)				; Print the iteration number
  (when (= i 10) (go end))		; Use the implicit tagbody and go to end tag when reach the last iteration
  (princ ", ")				; Printing the comma is jumped by the go statement
 end)					; The tag

or

(do	                                ; Not exactly separate statements for the number and the comma
 ((i 1 (incf i)))	                ; Initialize to 1 and increment on every loop
 ((> i 9) (princ i))                    ; Break condition when iteration is the last number, print it
  (princ i)	                        ; Print number statement
  (princ ", "))	                        ; Print comma statement

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Cowgol

include "cowgol.coh";

var i: uint8 := 1;
loop    
    print_i8(i);
    if i == 10 then break; end if;
    print(", ");
    i := i + 1;
end loop;
print_nl();

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

D

Iterative

import std.stdio;
 
void main() {
    for (int i = 1; ; i++) {
        write(i);
        if (i >= 10)
            break;
        write(", ");
    }

    writeln();
}

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Functional Style

void main() {
    import std.stdio, std.range, std.algorithm, std.conv, std.string;
    iota(1, 11).map!text.join(", ").writeln;

    // A simpler solution:
    writefln("%(%d, %)", iota(1, 11));
}

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Dart

String loopPlusHalf(start, end) {
  var result = '';
  for(int i = start; i <= end; i++) {
    result += '$i';
    if(i == end) {
      break;
    }
    result += ', ';
  }
  return result;
}

void main() {
  print(loopPlusHalf(1, 10));
}

Delphi

program LoopsNPlusOneHalf;

{$APPTYPE CONSOLE}

var
  i: integer;
const
  MAXVAL = 10;
begin
  for i := 1 to MAXVAL do
  begin
    Write(i);
    if i < MAXVAL then
      Write(', ');
  end;
  Writeln;
end.

Draco

proc nonrec main() void:
    byte i;
    i := 1;
    while
        write(i);
        i := i + 1;
        i <= 10
    do  
        write(", ")
    od
corp

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

DWScript

var i : Integer;

for i := 1 to 10 do begin
   Print(i);
   if i < 10 then
      Print(', ');
end;

E

A typical loop+break solution:

var i := 1
while (true) {
    print(i)
    if (i >= 10) { break }
    print(", ")
    i += 1
}

Using the loop primitive in a semi-functional style:

var i := 1
__loop(fn {
    print(i)
    if (i >= 10) {
        false
    } else {
        print(", ")
        i += 1
        true 
    }
})

EasyLang

for i = 1 to 10
   write i
   if i < 10
      write ", "
   .
.

EchoLisp

(string-delimiter "")

(for ((i (in-range 1 11))) (write i) #:break (= i 10) (write ","))
 → 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 

;; or

(string-join (range 1 11) ",")
   → 1,2,3,4,5,6,7,8,9,10

EDSAC order code

[ N and a half times loop
  =======================

  A program for the EDSAC

  Works with Initial Orders 2 ]

        T56K
        GK

        O16@
[  1 ]  T24@
        A25@
        A18@
        U25@
        S23@
        E11@

        O25@
        O19@
        O20@
        G1@

[ 11 ]  O18@
        O17@
        O21@
        O22@
        ZF

[ 16 ]  #F
[ 17 ]  PF
[ 18 ]  QF
[ 19 ]  NF
[ 20 ]  !F
[ 21 ]  @F
[ 22 ]  &F
[ 23 ]  JF
[ 24 ]  PF
[ 25 ]  PF

        EZPF

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Alternative

In the original EDSAC solution, the last number is printed outside the loop. My understanding of the task is that all numbers should be printed inside the loop, and control should then pass out of the loop without printing a comma after the last number.

To avoid dragging in a number-printing subroutine just to print 10, the output from the subroutines below has been changed to the single digits 0..9.

The first subroutine sticks to the task description: "in the last iteration, execute only part of the loop body". Two conditional jumps are encountered each time round the loop. The second subroutine skips the first part of the first iteration. This may not exactly fit the task description, but it has the advantage of requiring only one conditional jump within the loop. Cf. the S-lang solution and the comment by its author.

[Loop-and-a-half for Rosetta Code.
 EDSAC program, Initial Orders 2.]
          T64K      [load at location 64 (arbitrary choice)]
          GK        [set @ (theta) parameter]
[Constants]
    [0]   OF        [digit 9]
    [1]   JF        [to inc digit after subtracting 9]
    [2]   #F        [figures mode]
    [3]   !F        [space]
    [4]   NF        [comma (in figures mode)]
    [5]   @F        [carriage return]
    [6]   &F        [line feed]
[Variable]
    [7]   PF        [current digit]

[First subroutine to print digits 0..9]
    [8]   A3F T20@  [plant return link as usual]
          T7@       [digit := 0]
   [11]   O7@       [loop: print digit]
          A7@ S@    [is digit 9?]
          E20@      [if so, jump to exit]
          O4@ O3@   [print comma and space]
          A1@       [inc digit in acc]
          T7@       [update digit in store]
          E11@      [always loop back]
   [20]   ZF        [(planted) return to caller with acc = 0]

[Second subroutine to print digits 0..9
 Instead of saying "print a comma after each digit except the last"
   it says "print a comma before each digit except the first".]
   [21]   A3F T33@  [plant return link as usual]
          T7@       [digit := 0]
          E29@      [jump into middle of loop]
   [25]   A1@       [loop: inc digit in acc]
          T7@       [update digit in store]
          O4@ O3@   [print comma and space]
   [29]   O7@       [print digit]
          A7@ S@    [is digit 9?]
          G25@      [if not, loop back]
   [33]   ZF        [(planted) return to caller with acc = 0]

[Enter with acc = 0]
   [34]   O2@       [set teleprinter to figures]
          A35@ G8@  [call first subroutine]
          O5@ O6@   [print CR, LF]
          A39@ G21@ [call second subroutine]
          O5@ O6@   [print CR, LF]
          O2@       [print dummy character to flush teleprinter buffer]
          ZF        [stop]
          E34Z      [define entry point]
          PF        [value of acc on entry (here = 0)]
[end]

Output:

0, 1, 2, 3, 4, 5, 6, 7, 8, 9
0, 1, 2, 3, 4, 5, 6, 7, 8, 9

Elixir

defmodule Loops do
  def n_plus_one_half([]), do: IO.puts ""
  def n_plus_one_half([x]), do: IO.puts x
  def n_plus_one_half([h|t]) do
    IO.write "#{h}, "
    n_plus_one_half(t)
  end
end

Enum.to_list(1..10) |> Loops.n_plus_one_half

Erlang

%% Implemented by Arjun Sunel
-module(loop).
-export([main/0]).
 
main() ->
	for_loop(1).    
 
 for_loop(N) ->
 	if N < 10 ->
		io:format("~p, ",[N] ),
		for_loop(N+1);
	true ->
		io:format("~p\n",[N])
	end.

ERRE

FOR I=1 TO 10 DO
    PRINT(I;)
    EXIT IF I=10
    PRINT(", ";)
END FOR

Euphoria

for i = 1 to 10 do
    printf(1, "%g", {i})
    if i < 10 then
        puts(1, ", ")
    end if
end for

While, yes, use of exit would also work here, it is slightly faster to code it this way, if only the last iteration has something different.

F#

Functional version that works for lists of any length

let rec print (lst : int list) =
    match lst with
    | hd :: [] ->
        printf "%i " hd
    | hd :: tl ->
        printf "%i, " hd
        print tl
    | [] -> printf "\n"

print [1..10]

Factor

: print-comma-list ( n -- )
    [ [1,b] ] keep '[
        [ number>string write ]
        [ _ = [ ", " write ] unless ] bi
    ] each nl ;

Falcon

for value = 1 to 10
    formiddle 
        >> value
        >> ", "
    end
    forlast: > value
end

Output:

prompt$ falcon forto.fal
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

FALSE

1[$9>~][$.", "1+]#.

Fantom

class Main
{
  public static Void main ()
  {
    for (Int i := 1; i <= 10; i++)
    {
      Env.cur.out.writeObj (i)
      if (i == 10) break
      Env.cur.out.writeChars (", ")
    }
    Env.cur.out.printLine ("")
  }
}

Forth

: comma-list ( n -- )
  dup 1 ?do  i 1 .r ." , " loop
  . ;

: comma-list ( n -- )
  dup 1+ 1 do
    i 1 .r
    dup i = if leave then   \ or DROP UNLOOP EXIT to exit loop and the function
    [char] , emit space
  loop drop ;

: comma-list ( n -- )
  1
  begin  dup 1 .r
         2dup <>
  while  ." , " 1+
  repeat 2drop ;

Fortran

Works with: FORTRAN version IV and later

C     Loops N plus one half - Fortran IV (1964)
      INTEGER I
      WRITE(6,301) (I,I=1,10)
  301 FORMAT((I3,','))
      END

Works with: Fortran version 77 and later

C     WARNING: This program is not valid ANSI FORTRAN 77 code. It uses
C     two nonstandard characters on the lines labelled 5001 and 5002.
C     Many F77 compilers should be okay with it, but it is *not*
C     standard.
      PROGRAM LOOPPLUSONEHALF
        INTEGER I, TEN
C       I'm setting a parameter to distinguish from the label 10.
        PARAMETER (TEN = 10)

        DO 10 I = 1, TEN
C         Write the number only.
          WRITE (*,5001) I

C         If we are on the last one, stop here. This will make this test
C         every iteration, which can slow your program down a little. If
C         you want to speed this up at the cost of your own convenience,
C         you could loop only to nine, and handle ten on its own after
C         the loop is finished. If you don't care, power to you.
          IF (I .EQ. TEN) GOTO 10

C         Append a comma to the number.
          WRITE (*,5002) ','
   10   CONTINUE

C       Always finish with a newline. This programmer hates it when a
C       program does not end its output with a newline.
        WRITE (*,5000) ''
        STOP

 5000   FORMAT (A)

C       Standard FORTRAN 77 is completely incapable of completing a
C       WRITE statement without printing a newline. This program would
C       be much more difficult (i.e. impossible) to write in the ANSI
C       standard, without cheating and saying something like:
C
C           WRITE (*,*) '1, 2, 3, 4, 5, 6, 7, 8, 9, 10'
C
C       The dollar sign at the end of the format is a nonstandard
C       character. It tells the compiler not to print a newline. If you
C       are actually using FORTRAN 77, you should figure out what your
C       particular compiler accepts. If you are actually using Fortran
C       90 or later, you should replace this line with the commented
C       line that follows it.
 5001   FORMAT (I3, $)
 5002   FORMAT (A, $)
C5001   FORMAT (T3, ADVANCE='NO')
C5001   FORMAT (A, ADVANCE='NO')
      END

Works with: Fortran version 90 and later

i = 1
do
  write(*, '(I0)', advance='no') i
  if ( i == 10 ) exit
  write(*, '(A)', advance='no') ', '
  i = i + 1
end do
write(*,*)

GAP

n := 10;
for i in [1 .. n] do
    Print(i);
    if i < n then
        Print(", ");
    else
        Print("\n");
    fi;
od;

GML

str = ""
for(i = 1; i <= 10; i += 1)
    {
    str += string(i)
    if(i != 10)
        str += ", "
    }
show_message(str)

Go

package main

import "fmt"

func main() {
    for i := 1; ; i++ {
        fmt.Print(i)
        if i == 10 {
            fmt.Println()
            break
        }
        fmt.Print(", ")
    }
}

Gosu

var out = System.out
for(i in 1..10) {
  if(i > 1) out.print(", ")
  out.print(i)
}

Groovy

Solution:

for(i in (1..10)) {
    print i
    if (i == 10) break
    print ', '
}

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Haskell

main :: IO ()
main = forM_ [1 .. 10] $ \n -> do
            putStr $ show n
            putStr $ if n == 10 then "\n" else ", "

You can also use intersperse :: a -> [a] -> [a]

intercalate ", " (map show [1..10])

Haxe

for (i in 1...11)
  Sys.print('$i${i == 10 ? '\n' : ', '}');

hexiscript

for let i 1; i <= 10; i++
  print i
  if i = 10; break; endif
  print ", "
endfor
println ""

HicEst

DO i = 1, 10
    WRITE(APPend) i
    IF(i < 10) WRITE(APPend) ", "
ENDDO

HolyC

U8 i, max = 10;
for (i = 1; i <= max; i++) {
  Print("%d", i);
  if (i == max) break;
  Print(", ");
}
Print("\n");

Icon and Unicon

procedure main()
every writes(i := 1 to 10) do 
   if i = 10 then break write()
   else writes(", ")
end

The above can be written more succinctly as:

every writes(c := "",1 to 10) do c := ","

IDL

Nobody would ever use a loop in IDL to output a vector of numbers - the requisite output would be generated something like this:

print,indgen(10)+1,format='(10(i,:,","))'

However if a loop had to be used it could be done like this:

for i=1,10 do begin
 print,i,format='($,i)'
 if i lt 10 then print,",",format='($,a)'
endfor

(which merely suppresses the printing of the comma in the last iteration);

or like this:

for i=1,10 do begin
 print,i,format='($,i)'
 if i eq 10 then break
 print,",",format='($,a)'
end

(which terminates the loop early if the last element is reached).

J

output=: verb define
  buffer=: buffer,y
)

loopy=: verb define
  buffer=: ''
  for_n. 1+i.10 do.
    output ":n
    if. n<10 do.
      output ', '
    end.
  end.
  echo buffer
)

Example use:

   loopy 0
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

That said, note that neither loops nor output statements are necessary:

   ;}.,(', ' ; ":)&> 1+i.10
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

And, note also that this sort of data driven approach can also deal with more complex issues:

   commaAnd=: ":&.> ;@,. -@# {. (<;._1 '/ and /') ,~ (<', ') #~ #  
   commaAnd i.5
0, 1, 2, 3 and 4

Java

public static void main(String[] args) {
    for (int i = 1; ; i++) {
        System.out.print(i);
        if (i == 10)
            break;
        System.out.print(", ");
    }
    System.out.println();
}

JavaScript

function loop_plus_half(start, end) {
    var str = '',
        i;
    for (i = start; i <= end; i += 1) {
        str += i;
        if (i === end) {
          break;
        }
        str += ', ';
    }
    return str;
}
 
alert(loop_plus_half(1, 10));

Alternatively, if we stand back for a moment from imperative assumptions about the nature and structure of computing tasks, it becomes clear that the problem of special transitional cases as a pattern terminates has no necessary connection with loops. (See the comments accompanying the ACL2, Haskell, IDL, J and R examples above and below, and see also some of the approaches taken in languages like Clojure and Scala.

If a JavaScript expression evaluates to an array [1 .. 10] of integers, for example, we can map that array directly to a comma-delimited string by using the Array.join() function, writing something like:

function range(m, n) {
  return Array.apply(null, Array(n - m + 1)).map(
    function (x, i) {
      return m + i;
    }
  );
}
 
console.log(
  range(1, 10).join(', ')
);

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Otherwise, any special transitional case at the end of a pattern can be handled by defining conditional values for one or more sub-expressions:

function range(m, n) {
  return Array.apply(null, Array(n - m + 1)).map(function (x, i) {
    return m + i;
  });
}

console.log(
  (function (nFrom, nTo) {
    var iLast = nTo - 1;

    return range(nFrom, nTo).reduce(
      function (accumulator, n, i) {
        return accumulator +
          n.toString() +

          (i < iLast ? ', ' : ''); // conditional sub-expression

      }, ''
    )
  })(1, 10)
);

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Otherwise

var s=1, e=10
for (var i=s; i<=e; i+=1) {
	document.write( i==s ? '' : ', ', i )
}

or

var s=1, e=10
for (;; s+=1) {
	document.write( s )
	if (s==e) break
	document.write( ', ' )
}

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10 

jq

In jq, it is idiomatic to view a range of integers with boundaries m and n as [m, n), i.e. including m but excluding n.

One approach is to construct the answer incrementally:
def loop_plus_half(m;n):
  if m<n then reduce range(m+1;n) as $i (m|tostring; . +  ", " + ($i|tostring))
  else empty
  end;

# An alternative that is shorter and perhaps closer to the task description because it uses range(m;n) is as follows:
def loop_plus_half2(m;n):
  [range(m;n) | if . == m then . else  ", ", . end | tostring] | join("");

Output:

loop_plus_half2(1;11)
# "1, 2, 3, 4, 5, 6, 7, 8, 9, 10"

Julia

The short-circuiting && is idiomatic to Julia - the second expression will only be evaluated if the first one is true.

for i = 1:10
  print(i)
  i == 10 && break
  print(", ")
end

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

K

   p:{`0:$x} / output
   i:1;do[10;p[i];p[:[i<10;", "]];i+:1];p@"\n"
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Alternative solutions:

   10 {p@x;p@:[x<10;", ";"\n"];x+1}\1;
   {p@x;p@:[x<10;", ";"\n"];x+1}'1+!10; /variant

Kotlin

// version 1.0.6

fun main(args: Array<String>) {
    for (i in 1 .. 10) {
        print(i)
        if (i < 10) print(", ")
    }
}

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

LabVIEW

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Lambdatalk

{def loops_N_plus_one_half
 {lambda {:i :n}
  {if {> :i :n}
   then (end of loop with a dot)
   else {if {= :i 6} then {br}:i else :i}{if {= :i :n} then . else ,}
        {loops_N_plus_one_half {+ :i 1} :n}}}}
-> loops_N_plus_one_half

{loops_N_plus_one_half 0 10}
-> 0, 1, 2, 3, 4, 5, 
6, 7, 8, 9, 10. (end of loop with a dot)

Lang

# Loop
$i = 1
loop {
	fn.print($i)
	if($i === 10) {
		con.break
	}
	
	fn.print(\,\s)
	
	$i += 1
}
fn.println()

# Array generate from and join
fn.println(fn.join(\,\s, fn.arrayGenerateFrom(fn.inc, 10)))

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Lang5

: ,  dup ", " 2 compress "" join ;
1 do dup 10 != if dup , . 1 + else . break then loop

Word: Loops/For#Lang5

: 2string  2 compress "" join ;
: ,  dup 10 != if ", " 2string then ;
1 10 "dup , . 1+" times

Lasso

local(out) = ''
loop(10) => {
    #out->append(loop_count)
    loop_count == 10 ? loop_abort
    #out->append(', ')
}
#out

Lhogho

type doesn't output a newline. The print outputs one.

for "i [1 10] 
[
	type :i
	if :i < 10 
	[
		type "|, |
	]
]
print

A more list-y way of doing it

to join :lst :sep
	if list? :lst
	[
		ifelse count :lst > 1
		[
			op (word first :lst :sep joinWith butfirst :lst :sep)
		]
		[
			op (word last :lst)
		]
	]
	op :lst
end

make "aList [1 2 3 4 5 6 7 8 9 10]
print join :aList "|, |

Lisaac

Section Header

+ name := LOOP_AND_HALF;

Section Public

- main <- (
  + i : INTEGER;

  i := 1;
  {
    i.print;
    i = 10
  }.until_do {
    ", ".print;
    i := i + 1;
  };
  '\n'.print;
);

LiveCode

repeat with n = 1 to 10
    put n after loopn
    if n is not 10 then put comma after loopn
end repeat
put loopn

Logo

to comma.list :n
  repeat :n-1 [type repcount type "|, |]
  print :n
end

comma.list 10

Lua

Translation of C:

for i = 1, 10 do
  io.write(i)
  if i == 10 then break end
  io.write", "
end

M2000 Interpreter

Module Checkit {
      \\ old type loop
      For i=1 to 10
            Print i;
            If i=10 Then Exit For
            Print ", ";
      Next i
      Print
      \\ fast type loop. Continue exit block, without breaking loop.
      For i=1 to 10 {
                  Print i;
                  If i=10 Then Continue
                  Print ", ";
      }
      Print
      Print
      i=0
      {
                  loop  \\ this mark block for loop, each time need to mark
                  i++
                  Print i;
                  If i=10 Then Exit  ' so now we use exit to break loop
                  Print ", ";      
      }
      Print
}
Checkit

M4

define(`break',
   `define(`ulim',llim)')
define(`for',
   `ifelse($#,0,``$0'',
   `define(`ulim',$3)`'define(`llim',$2)`'ifelse(ifelse($3,`',1,
         `eval($2<=$3)'),1,
   `pushdef(`$1',$2)$4`'popdef(`$1')$0(`$1',incr($2),ulim,`$4')')')')

for(`x',`1',`',
   `x`'ifelse(x,10,`break',`, ')')

Make

NEXT=`expr $* + 1`
MAX=10
RES=1

all: 1-n;

$(MAX)-n:
       @echo $(RES)

%-n:
       @-make -f loop.mk $(NEXT)-n MAX=$(MAX) RES=$(RES),$(NEXT)

Invoking it

|make -f loop.mk MAX=10
1,2,3,4,5,6,7,8,9,10

Maple

> for i to 10 do printf( "%d%s", i, `if`( i = 10, "\n", ", " ) ) end:
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Mathematica/Wolfram Language

i = 1; s = "";
While[True,
 s = s <> ToString@i;
 If[i == 10, Break[]];
 s = s <> ",";
 i++;
 ]
s

MATLAB / Octave

Vectorized form:

 	printf('%i, ',1:9); printf('%i\n',10);

Explicite loop:

   for k=1:10,
      printf('%i', k); 
   if k==10, break; end;
      printf(', ');
   end; 
   printf('\n');

Output:

  1, 2, 3, 4, 5, 6, 7, 8, 9, 10 

MAXScript

for i in 1 to 10 do
(
    format "%" i
    if i == 10 then exit
    format "%" ", "
)

Metafont

Since message append always a newline, we need building the output inside a string, and then we output it.

last := 10;
string s; s := "";
for i = 1 upto last:
  s := s & decimal i;
  if i <> last: s := s & ", " fi;
endfor
message s;
end

min

min's linrec combinator is flexible enough to easily accomodate this task, due to taking a quotation to execute at the end of the loop (the second one).

1 (dup 10 ==) 'puts! (print succ ", " print!) () linrec

Modula-3

MODULE Loop EXPORTS Main;

IMPORT IO, Fmt;

VAR i := 1;

BEGIN
  LOOP
    IO.Put(Fmt.Int(i));
    IF i = 10 THEN EXIT; END;
    IO.Put(", ");
    i := i + 1;
  END;
  IO.Put("\n");
END Loop.

MUMPS

LOOPHALF
 NEW I
 FOR I=1:1:10 DO
 .WRITE I
 .IF I'=10 WRITE ", "
 QUIT
 ;Alternate
 NEW I FOR I=1:1:10 WRITE I WRITE:I'=10 ", "
 KILL I QUIT

Output:

USER>D LOOPHALF^ROSETTA
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
USER>D LOOPHALF+7^ROSETTA
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Nemerle

foreach (i in [1 .. 10])
{
    Write(i);
    unless (i == 10) Write(", ");
}

NetRexx

/* NetRexx */
/* NetRexx */
options replace format comments java crossref savelog symbols nobinary

  say
  say 'Loops/N plus one half'

  rs = ''
  istart = 1
  iend   = 10
  loop i_ = istart to iend
    rs = rs || ' ' || i_
    if i_ < iend then do
      rs = rs','
      end
    end i_
  say rs.strip()

Output

Loops/N plus one half
1, 2, 3, 4, 5, 6, 7, 8, 9, 10

NewLISP

(for (i 0 10)
  (print i)
  (unless (= i 10)
    (print ", ")))

Nim

var s = ""
for i in 1..10:
  s.add $i
  if i == 10: break
  s.add ", "
echo s

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Objeck

bundle Default {
  class Hello {
    function : Main(args : String[]) ~ Nil {
      for(i := 1; true; i += 1;) {
        i->Print();
        if(i = 10) {
          break;
        };
        ", "->Print();
      };
      '\n'->Print();
    }
  }
}

OCaml

let last = 10 in
for i = 1 to last do
  print_int i;
  if i <> last then
    print_string ", ";
done;
print_newline();

let ints = [1; 2; 3; 4; 5; 6; 7; 8; 9; 10] in
let str_ints = List.map string_of_int ints in
print_endline (String.concat ", " str_ints);

Oforth

: loopn
| i |
   10 loop: i [ i dup print 10 ifEq: [ break ] "," . ] printcr ;

Oz

Using a for-loop:

for N in {List.number 1 10 1} break:Break do
   {System.printInfo N}
   if N == 10 then {Break} end
   {System.printInfo ", "}
end

However, it seems more natural to use a left fold:

declare
  fun {CommaSep Xs}
     case Xs of nil then nil
     [] X|Xr then
	{FoldL Xr 
	 fun {$ Z X} Z#", "#X end
	 X}
     end
  end
in
  {System.showInfo {CommaSep {List.number 1 10 1}}}

Panda

Panda is stream based. To know if there is no more values you need to know it's the last. You can only do that if you get all the values. So this is functional style; We accumulate all the values from the stream. Then join them together as strings with a comma.

array{{1..10}}.join(',')

PARI/GP

n=0;
while(1,
  print1(n++);
  if(n>9, break);
  print1(", ")
);

Pascal

program numlist(output);

const MAXNUM: integer = 10;
var
  i: integer;

begin
  { loop 1: w/ if branching }
  for i := 1 to MAXNUM do
    begin
      write(i);
      if i <> MAXNUM then
        write(', ')
    end;
  writeln;
  { loop 2: w/o if branching }
  for i := 1 to MAXNUM-1 do
    write(i, ', ');
  writeln(MAXNUM);
end.

Peloton

<@ FORLITLIT>10|<@ SAYPOSFOR>...</@><@ ABF>,</@></@>

Perl

for my $i(1..10) {
    print $i;
    last if $i == 10;
    print ', ';
}
print "\n";

In perl one would solve the task via join.

print join(', ', 1..10), "\n";

Phix

for i=1 to 10 do
    printf(1,"%d",i)
    if i=10 then exit end if
    printf(1,", ")
end for

Phixmonti

/# Rosetta Code problem: https://rosettacode.org/wiki/Loops/N_plus_one_half
by Galileo, 11/2022 #/

10 for dup print 10 == not if ", " print endif endfor

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10
=== Press any key to exit ===

PHP

for ($i = 1; $i <= 11; $i++) {
    echo $i;
    if ($i == 10)
        break;
    echo ', ';
}
echo "\n";

PicoLisp

(for N 10
   (prin N)
   (T (= N 10))
   (prin ", ") )

Pike

int main(){
   for(int i = 1; i <= 11; i++){
      write(sprintf("%d",i));
      if(i == 10){
         break;
      }
      write(", ");
   }
   write("\n");
}

The most idiomatic way of inserting delimiters in Pike is the multiplication operator and it's symmetry with division of strings.

> "1, 2, 3"/", ";
Result: ({ "1", "2", "3" })
> ({ "1", "2", "3" })*", ";
Result: "1, 2, 3"

So achieving the result of this task with the method more suited to Pike would be:

array a = (array(string))enumerate(10, 1, 1);
write(a * ", " + "\n");

PL/I

do i = 1 to 10;
   put edit (trim(i)) (a);
   if i < 10 then put edit (', ') (a);
end;

Plain English

To run:
Start up.
Write the numbers up to 10 on the console.
Wait for the escape key.
Shut down.

To write the numbers up to a number on the console:
If a counter is past the number, exit.
Convert the counter to a string.
Write the string on the console without advancing.
If the counter is less than the number, write ", " on the console without advancing.
Repeat.

Pop11

lvars i;
for i from 1 to 10 do
    printf(i, '%p');
    quitif(i = 10);
    printf(', ', '%p');
endfor;
printf('\n', '%p');

PowerShell

Translation of: C

for ($i = 1; $i -le 10; $i++) {
    Write-Host -NoNewLine $i
    if ($i -eq 10) {
        Write-Host
        break
    }
    Write-Host -NoNewLine ", "
}

An interesting alternative solution, although not strictly a loop, even though switch certainly loops over the given range.

switch (1..10) {
    { $true }     { Write-Host -NoNewLine $_ }
    { $_ -lt 10 } { Write-Host -NoNewLine ", " }
    { $_ -eq 10 } { Write-Host }
}

Prolog

example :- 
  between(1,10,Val), write(Val), Val<10, write(', '), fail.
example.

?- example.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
true.

Python

The particular pattern and example chosen in the task description is recognised by the Python language and there are more idiomatic ways to achieve the result that don't even require an explicit conditional test such as:

print ( ', '.join(str(i+1) for i in range(10)) )

But the named pattern is shown by code such as the following:

>>> from sys import stdout
>>> write = stdout.write
>>> n, i = 10, 1
>>> while True:
    write(i)
    i += 1
    if i > n:
        break
    write(', ')

    
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
>>>

List comprehension one-liner

[print(str(i+1) + ", ",end='') if i < 9 else print(i+1) for i in range(10)]

Works with: Python version 3.x

n, i = 10, 1
while True:
    print(i, end="")
    i += 1
    if i > n:
        break
    print(", ", end="")

Quackery

  10 times 
     [ i^ 1+ echo
       i 0 = iff 
          conclude done
       say ", " ]

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

R

The natural way to solve this task in R is:

paste(1:10, collapse=", ")

The task specifies that we should use a loop however, so this more verbose code is needed.

for(i in 1:10)
{
   cat(i)
   if(i==10) 
   {
      cat("\n")
      break
   }
   cat(", ")
}

Racket

#lang racket
(for ((i (in-range 1 15)))
  (display i)
  #:break (= 10 i)
  (display ", "))

Gives the desired output.

Raku

(formerly Perl 6)

for 1 .. 10 {
    .print;
    last when 10;
    print ', ';
}

print "\n";

REBOL

REBOL [
    Title: "Loop Plus Half"
    URL: http://rosettacode.org/wiki/Loop/n_plus_one_half
]

repeat i 10 [
	prin i
	if 10 = i [break]
	prin ", "
]
print ""

Red

Red[]

repeat i 10 [
    prin i
    if 10 = i [break]
    prin ", "
]
print ""

Relation

set i = 1
set result = ""
while i <= 10
set result = result . i
if i < 10
set result = result . ", "
end if
set i = i + 1
end while
echo result

REXX

two CHAROUTs

/*REXX program displays:                 1,2,3,4,5,6,7,8,9,10                           */

     do j=1  to 10
     call charout ,j                             /*write the  DO loop  index  (no LF).  */
     if j<10  then call charout ,","             /*append a comma for one-digit numbers.*/
     end   /*j*/
                                                 /*stick a fork in it,  we're all done. */

output

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

one CHAROUT

/*REXX program displays:                 1,2,3,4,5,6,7,8,9,10                           */

     do j=1  for 10                              /*using   FOR   is faster than    TO.  */
     call charout ,j || left(',',j<10)           /*display  J, maybe append a comma (,).*/
     end   /*j*/
                                                 /*stick a fork in it,  we're all done. */

output

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

version 3 if the number of items is not known

list='aa bb cc dd'
sep=', '
Do i=1 By 1 While list<>''
  If i>1 Then Call charout ,sep
  Parse Var list item list
  Call charout ,item
  End

Output:

aa, bb, cc, dd

Ring

for x = 1 to 10 see x if x=10 exit ok see ", " next see nl

RPL

There are basically 2 possibilities, based on an overarching FOR..NEXT or DO..UNTIL / WHILE..REPEAT loop structure, in which an IF..THEN..ELSE decides which parts of the loop must be executed. RPL does not have any instruction to just exit a loop. The DO..UNTIL / WHILE..REPEAT approach requires to use a flag and to manage a counter, which weighs down the code, as it can be seen in the implementations below.

≪ ""
   1 10 FOR j
      j →STR +
      IF j 10 < THEN ", " + END
  NEXT
≫ 'S1→10' STO

17 words

≪ 1 CF "" 0 
   DO
      1 + SWAP OVER →STR +
      IF OVER 10 < THEN ", " + ELSE 1 SF END
      SWAP
   UNTIL 1 FS? END
   DROP
≫  'S1→10' STO

28 words + 1 flag

Ruby

(1..10).each do |i|
  print i
  break if i == 10
  print ", "
end
puts

More idiomatic Ruby to obtain the same result is:

puts (1..10).join(", ")

Rust

fn main() {
    for i in 1..=10 {
        print!("{}{}", i, if i < 10 { ", " } else { "\n" });
    }
}

More like the problem description:

fn main() {
    for i in 1..=10 {
        print!("{}", i);
        if i == 10 { 
            break;
        }
        print!(", ");
    }
    println!();
}

Alternative solution using join.

fn main() {
    println!(
        "{}",
        (1..=10)
            .map(|i| i.to_string())
            .collect::<Vec<_>>()
            .join(", ")
    );
}

S-lang

This may constitute not following directions, but I've always felt the most readable and general way to code this is to move the "optional" part from the bottom to the top of the loop, then NOT include it on the FIRST pass:

variable more = 0, i;
foreach i ([1:10]) {
  if (more) () = printf(", ");
  printf("%d", i);
  more = 1;
}

Salmon

iterate (x; [1...10])
  {
    print(x);
    if (x == 10)
        break;;
    print(", ");
  };
print("\n");

Scala

Library: Scala

var i = 1
while ({
  print(i)
  i < 10
}) {
  print(", ")
  i += 1
}
println()

println((1 to 10).mkString(", "))

Scheme

It is possible to use continuations:

(call-with-current-continuation
 (lambda (esc)
   (do ((i 1 (+ 1 i))) (#f)
     (display i)
     (if (= i 10) (esc (newline)))
     (display ", "))))

But usually making the tail recursion explicit is enough:

(let loop ((i 0))
  (display i)
  (if (= i 10)
      (newline)
      (begin
        (display ", ")
        (loop (+ 1 i)))))

Scilab

Works with: Scilab version 5.5.1

for i=1:10
    printf("%2d ",i)
    if i<10 then printf(", "); end
end
printf("\n")

Output:

 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 , 10 

Seed7

$ include "seed7_05.s7i";

const proc: main is func
  local
    var integer: number is 0;
  begin
    for number range 1 to 10 do
      write(number);
      if number < 10 then
        write(", ")
      end if;
    end for;
    writeln;
  end func;

Sidef

for (1..10) { |i|
    print i;
    i == 10 && break;
    print ', ';
}

print "\n";

Smalltalk

1 to: 10 do: [:n |
    Transcript show: n asString.
    n < 10 ifTrue: [ Transcript show: ', ' ]
]

Smalltalk/X and Pharo/Squeak have special enumeration messages for this in their Collection class, which executes another action in-between iterated elements:

Works with: Smalltalk/X

Works with: Pharo

(1 to: 10) do: [:n |
    Transcript show: n asString.
] separatedBy:[
    Transcript show: ', '
]

That is a bit different from the task's specification, but does what is needed here, and is more general in working with any collection (in the above case: a range aka "Interval"). It does not depend on the collection being addressed by an integer index and/or keeping a count inside the loop.

SNOBOL4

It's idiomatic in Snobol to accumulate the result in a string buffer for line output, and to use the same statement for loop control and the comma.

loop    str = str lt(i,10) (i = i + 1) :f(out)
        str = str ne(i,10) ',' :s(loop)
out     output = str
end

Works with: Macro Spitbol

For the task description, it's possible (implementation dependent) to set an output variable to raw mode for character output within the loop.

This example also breaks the loop explicitly:

        output('out',1,'-[-r1]')
loop    i = lt(i,10) i + 1 :f(end)
        out = i
        eq(i,10) :s(end)
        out = ',' :(loop)
end

Output:

1,2,3,4,5,6,7,8,9,10

SNUSP

@\>@\>@\>+++++++++<!/+.  >-?\#  digit and loop test
 |  |  \@@@+@+++++# \>>.<.<</    comma and space
 |  \@@+@@+++++#      
 \@@@@=++++#

Spin

Works with: BST/BSTC

Works with: FastSpin/FlexSpin

Works with: HomeSpun

Works with: OpenSpin

con
  _clkmode = xtal1 + pll16x
  _clkfreq = 80_000_000

obj
  ser : "FullDuplexSerial.spin"

pub main | n
  ser.start(31, 30, 0, 115200)

  repeat n from 1 to 10
    ser.dec(n)
    if n<10
      ser.str(string(", "))
  ser.str(string(13, 10))

  waitcnt(_clkfreq + cnt)
  ser.stop
  cogstop(0)

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Stata

forv i=1/10 {
	di `i' _continue
	if `i'<10 {
		di ", " _continue
	}
	else {
		di
	}
}

Mata

mata
for (i=1; i<=10; i++) {
	printf("%f",i)
	if (i<10) {
		printf(", ")
	} else {
		printf("\n")
	}
}
end

Swift

Works with: Swift version 1.x

for var i = 1; ; i++ {
    print(i)
    if i == 10 {
        println()
        break
    }
    print(", ")
}

Works with: Swift version 2

The usual way to do this with Swift 2 is:

for i in 1...10 {
    
    print(i, terminator: i == 10 ? "\n" : ", ")
}

To satisfy the specification, we have to do something similar to Swift 1.x and other C-like languages:

for var i = 1; ; i++ {
    print(i, terminator: "")
    if i == 10 {
        print("")
        break
    }
    print(", ", terminator: "")
}

Tcl

for {set i 1; set end 10} true {incr i} {
    puts -nonewline $i
    if {$i >= $end} break
    puts -nonewline ", "
}
puts ""

However, that's not how the specific task (printing 1..10 with comma separators) would normally be done. (Note, the solution below is not a solution to the half-looping problem.)

proc range {from to} {
    set result {}
    for {set i $from} {$i <= $to} {incr i} {
        lappend result $i
    }
    return $i
}
 
puts [join [range 1 10] ", "] ;# ==> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

TUSCRIPT

$$ MODE TUSCRIPT
line=""
LOOP n=1,10
 line=CONCAT (line,n)
 IF (n!=10) line=CONCAT (line,", ")
ENDLOOP
PRINT line

Output:

1,  2,  3,  4,  5,  6,  7,  8,  9,  10

UNIX Shell

for(( Z=1; Z<=10; Z++ )); do
    echo -e "$Z\c"
    if (( Z != 10 )); then
        echo -e ", \c"
    fi
done

Works with: Bash

for ((i=1;i<=$((last=10));i++)); do
  echo -n $i
  [ $i -eq $last ] && break
  echo -n ", "
done

UnixPipes

The last iteration is handled automatically for us when there is no element in one of the pipes.

yes \ | cat -n | head -n 10 | paste -d\  - <(yes , | head -n 9) | xargs echo

Ursa

Translation of: PHP

decl int i
for (set i 1) (< i 11) (inc i)
        out i console
        if (= i 10)
                break
        end if
        out ", " console
end for
out endl console

V

[loop 
   [ [10 =] [puts]
     [true] [dup put ',' put succ loop]
   ] when].

Using it

|1 loop
=1,2,3,4,5,6,7,8,9,10

Vala

Translation of: C

void main() {
  for (int i = 1; i <= 10; i++)
  {
    stdout.printf("%d", i);
    stdout.printf(i == 10 ? "\n" : ", ");
  }
}

Vedit macro language

This example writes the output into current edit buffer.

for (#1 = 1; 1; #1++) {
    Num_Ins(#1, LEFT+NOCR)
    if (#1 == 10) { Break }
    Ins_Text(", ")
}
Ins_Newline

Verilog

module main;
  integer  i;
  
  initial begin
    for(i = 1; i <= 10; i = i + 1)  begin
        $write(i);
        if (i < 10 ) $write(", ");
    end
  $display("");
  $finish ;
  end
endmodule

Output:

1,           2,           3,           4,           5,           6,           7,           8,           9,          10

Vim Script

for i in range(1, 10)
   echon i
   if (i != 10)
      echon ", "
   endif
endfor

V (Vlang)

fn main() {
    for i := 1; ; i++ {
        print(i)
        if i == 10 {
            break
        }
        print(", ")
    }
}

Wart

for i 1 (i <= 10) ++i
  pr i
  if (i < 10)
    pr ", "
(prn)

Wren

for (i in 1..10) {
    System.write(i)
    System.write((i < 10) ? ", " : "\n")
}

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10

XPL0

codes CrLf=9, IntOut=11, Text=12;
int  N;
[for N:= 1 to 10 do     \best way to do this
        [IntOut(0, N);  if N#10 then Text(0, ", ")];
CrLf(0);

N:= 1;                  \way suggested by task statement
loop    [IntOut(0, N);
        if N=10 then quit;
        Text(0, ", ");
        N:= N+1;
        ];
CrLf(0);
]

zkl

foreach n in ([1..10]){ print(n); if (n!=10) print(",") }

Or, using a state machine:

[1..10].pump(Console.print, Void.Drop, T(Void.Write,",",Void.Drop));

where pump is (sink, action, action ...). The first Drop writes the first object from the source (1) to the sink and drops out (and that iteration of the loop is done). For the rest of the loop, Write collects things to write to the sink: a comma and the number, eg ",2". Or:

[1..10].pump(Console.print, Void.Drop, fcn(n){ String(",",n) });

Zig

const std = @import("std");
pub fn main() !void {
    const stdout_wr = std.io.getStdOut().writer();
    var i: u8 = 1;
    while (i <= 10) : (i += 1) {
        try stdout_wr.print("{d}", .{i});
        if (i == 10) {
            try stdout_wr.writeAll("\n");
        } else {
            try stdout_wr.writeAll(", ");
        }
    }
}