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.

Ada[edit]

The specification of a class Word_Wrap.Basic in a package Word_Wrap:

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;

The implementation of that package:

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;

Finally, the main program:

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;
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[edit]

Basic word-wrap. Formats text that has been copied to the clipboard.

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
}
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[edit]

Basic word wrap.

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)
}

To test it,

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

Batch File[edit]

Basic word wrap.

@echo off
setlocal enabledelayedexpansion

	%== Setting the new line character ==%
set ^"nl=^

^" %== The blank line above is required... ==%

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."
	%== Call the Function (The second parameter is the line width) ==%
call :wrap "%input%" 40
call :wrap "%input%" 70
pause>nul
exit /b 0

	%== The Function... ==%
:wrap
set output=&set limit=
set tmp_str=%~1&set width=%2
:proc_loop
	%== Check if we're already done ==%
if "!tmp_str!"=="" (
	echo.
	echo !output!
	goto :EOF
)
	%== If not yet done, scan the next word... ==%
for /f "tokens=1,* delims= " %%A in ("!tmp_str!") do (
	set tmp_str=%%B&set word=%%A&set str=%%A

	%== The next line is an alternative for counting the word length ==%
	set leng=0&if not "!str!"=="" for /l %%. in (0,1,1000) do if not "!str:~%%.,1!"=="" set /a leng+=1
 
	set /a "limit+=!leng!" %== Check if we should make a new line or not... ==%
	if !limit! gtr !width! (
		set /a limit=!leng!+1
		set "output=!output!!nl!!word! "
	) else (
		set /a limit+=1
		set "output=!output!!word! "
	)
)
goto proc_loop
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[edit]

(     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)))
);
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[edit]

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#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.
*/

 
#define PENALTY_LONG 100
#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;
}

C++[edit]

Basic task.

Translation of: Go
#include <iostream>
#include <sstream>
#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";
}
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.

C#[edit]

Greedy algorithm:

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;
}
}
}
}
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.

Clojure[edit]

;; 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))))))
;; Wrap line base on regular expression
(defn wrap-line [size text]
(re-seq (re-pattern (str ".{0," size "}\\s"))
(clojure.string/replace text #"\n" " ")))

Usage example :

(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))
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[edit]

;; 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)) )))
 
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[edit]

Standard Version[edit]

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));
}
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[edit]

Basic algorithm. The text splitting is lazy.

Translation of: Go
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));
}
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.

Elixir[edit]

Translation of: Erlang
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)
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[edit]

 
-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}.
 
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#[edit]

Translation of: C#
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
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.

Forth[edit]

\ 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

Fortran[edit]

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,
      CHARACTER*12345 TEXT
...
DO I = 0,120
WRITE (6,*) TEXT(I*80 + 1:(I + 1)*80)
END DO

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.

 
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

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[edit]

Basic task, no extra credit.

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))
}
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[edit]

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()
}

Testing:

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)
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.

Haskell[edit]

Greedy wrapping:

ss = "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 = do
putStr $ wordwrap 72 ss
putStr "\n"
putStr $ wordwrap 32 ss


Alternative greedy wrapping:
import Data.List
 
teststring = "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

Icon and Unicon[edit]

The following works in both languages.

 
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

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
->

J[edit]

Solution:
ww        =:  75&$: : wrap
wrap =: (] turn edges) ,&' '
turn =: LF"_`]`[}
edges =: (_1 + ] #~ 1 ,~ 2 >/\ |) [: +/\ #;.2
Example:
   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.

Java[edit]

 
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);
}
 
}
 
 


JavaScript[edit]

Recursive[edit]

Solution:
 
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;
}
 
Example:
 
console.log(wrap(text, 80));
 
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:
 
console.log(wrap(text, 42));
 
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[edit]

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

(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);
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[edit]

 
/**
* [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
}
 
Example
 
console.log(wordwrap("The quick brown fox jumped over the lazy dog.", 20, "<br />\n"));
 
Output:
The quick brown fox<br />
jumped over the lazy<br />
dog.

jq[edit]

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.

# Simple greedy algorithm.
# Note: very long words are not truncated.
# input: a string
# 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 );

Task 1:

"aaa bb cc ddddd" | wrap_text(6)[]  # wikipedia example
Output:
aaa bb
cc
ddddd

Task 2:

"aaa bb cc ddddd" | wrap_text(5)[]
Output:
aaa
bb cc
ddddd

With input from a file: 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.
 

Main:

wrap_text(40)[]
Output:
$ 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.
 

Lasso[edit]

define wordwrap(
text::string,
row_length::integer = 75
) => {
return regexp(`(?is)(.{1,` + #row_length + `})(?:$|\W)+`, '$1<br />\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)
'<hr />'
wordwrap(#text)
'<hr />'
wordwrap(#text, 90)
->
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[edit]

Naive Implementation[edit]

Translation of: Erlang
 
(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)))
 

Regex Implementation[edit]

 
(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)))))
 

Usage examples:

 
> (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))
 
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
 
> (io:format (wrap-text text 50))
 
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[edit]

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)

-- 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

Usage:

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
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[edit]

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))
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.

Mathematica[edit]

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>[email protected]@string
,
p=StringSplit[string][[start;;i]];
AppendTo[masterString,{StringJoin@@Riffle[p,[email protected][" ",spaceWidth]]}]
,
If[StringLength[[email protected]][[i+1]]+spaceWidth>spaceLeft
,
spaceLeft=textWidth-StringLength[[email protected]][[i]];
start=i;
AppendTo[masterString,{StringJoin@@Riffle[p,[email protected][" ",spaceWidth]]}]
,
spaceLeft-=StringLength[[email protected]][[i]];
spaceLeft-=spaceWidth;
p=StringSplit[string][[start;;i]]
]
]
,
{i,1,[email protected]@string}
];
StringJoin@@Riffle[masterString,"\n"]
];
Output:
for width 72 and 80:
wordWrap[72, 1, string]
wordWrap[80, 1, string]
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.


NetRexx[edit]

version 1[edit]

/* 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!' -
'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)' -
''
return speech01
 
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[edit]

/* 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

Nim[edit]

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)
 
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[edit]

#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)

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

PARI/GP[edit]

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)
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[edit]

Regex. Also showing degraded behavior on very long words:

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;

Perl 6[edit]

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);

PicoLisp[edit]

'wrap' is a built-in.

: (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"

PL/I[edit]

*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;

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[edit]

Basic word wrap.

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"
}
 
### 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
 
### End script
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[edit]

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.

 
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
}
}
}
 

Grab some data and send it down the pipeline:

 
[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
 
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[edit]

 
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()
 
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[edit]

>>> 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.
>>> 

R[edit]

Use strwrap():

> 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.


Racket[edit]

Using a library function:

 
#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))
 

Explicit (and simple) implementation:

 
#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)
 

REXX[edit]

version 0[edit]

This version was the original (of version 1) and has no error checking and only does left-margin justification.

/*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. */

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

version 1[edit]

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.

/*REXX program  reads  a file  and  displays  it to the screen  (with word wrap).       */
parse arg iFID width justify _ . /*obtain optional arguments from the CL*/
if iFID=='' | iFID=="," then iFID ='LAWS.TXT' /*Not specified? Then use the defaul.t*/
if width=='' |width=="," then width=linesize() /* " " " " " " */
if right(width, 1)=='%' then width=linesize() * translate(width, , "%") % 100
if justify==''|justify=="," then justify='Left' /*Default? Then use the default: LEFT */
just=left(justify, 1) /*only use first char of JUSTIFY. */
upper just /*be able to handle mixed case. */
if pos(just, 'BCLR')==0 then call err "JUSTIFY (3rd arg) is illegal:" justify
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 /*DO 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'. */

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 specifying:     ,   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.) ∙ Parameters are variables traveling under an
assumed name.
Output:
when specifying: , 77
────────── 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: , 70 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[edit]

/* 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))
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

Ruby[edit]

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
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[edit]

Word Wrap style for different browsers. This automatically adjusts the text if the browser window is stretched in any direction

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 "<table border=1 cellpadding=2 cellspacing=0><tr" + wrap$ +" valign=top>"
html "<td width=60%>" + doc$ + "</td><td width=40%>" + doc$ + "</td></tr></table>"

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

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$

Scala[edit]

Intuitive approach[edit]

Library: 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
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

Seed7[edit]

$ 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;
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[edit]

Greedy word wrap[edit]

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);
Output:
aaa bb
cc
ddddd

Smart word wrap[edit]

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;
Output:
aaa
bb cc
ddddd

Tcl[edit]

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.

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]
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[edit]

The text presentation program automatically provides word wrap:

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

TUSCRIPT[edit]

 
$$ 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
 
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[edit]

 
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
 
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.

zkl[edit]

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.

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
}
formatText(File("frog.txt")).text.println();
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 ...
[1..].zipWith("%2d: %s".fmt,formatText(File("frog.txt")).walker(1))
.sink(String).walk().println();
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.
formatText("this\n   is a test foo bar\n\ngreen eggs and spam",10).text.println();
Output:
this is a
   test
   foo bar

green eggs
and spam