Golang : Simple word wrap or line breaking example



Tags : golang line-break word-wrap slice-string

Problem:

You have a long text string and you want to wrap the text according to a given number of words per line so that the output will fit nicely to display on terminal or web page. Or you want to split a long text string into multiple lines after a given length(number of words). How to do that?

Solution:

This is a simple and primitive line breaking/word wrap solution that should work for most cases.

  • convert the string into slice
  • push out the words into a line according to the given limit/length and append each line with \r\n,

Here you go!

 package main

 import (
 "fmt"
 "strings"
 )

 // Wraps text at the specified number of columns

 func word_wrap(s string, limit int) string {

 if strings.TrimSpace(s) == "" {
 return s
 }

 // convert string to slice
 strSlice := strings.Fields(s)

 var result string = ""

 for len(strSlice) >= 1 {
 // convert slice/array back to string
 // but insert \r\n at specified limit

 result = result + strings.Join(strSlice[:limit], " ") + "\r\n"

 // discard the elements that were copied over to result
 strSlice = strSlice[limit:]

 // change the limit
 // to cater for the last few words in
 //
 if len(strSlice) < limit {
 limit = len(strSlice)
 }

 }

 return result

 }

 func main() {

 str := "Here is a nice text string consisting of eleven words."
 fmt.Printf("Original : [%v] \n", str)
 // limit to 3 words
 fmt.Println(word_wrap(str, 3))

 strWithDoubleSpaces := "This code example will attempt to word  warp this text string - 'Here is a nice text string consisting of eleven words.'"
 fmt.Printf("Original : [%v] \n", strWithDoubleSpaces)
 // limit to 7 words
 fmt.Println(word_wrap(strWithDoubleSpaces, 7))

 unicodeStrWithDoubleSpaces := "Here is a nice text string consisting of eleven words and some unicode characters such as 世界你好."
 fmt.Printf("Original : [%v] \n", unicodeStrWithDoubleSpaces)
 // limit to 5 words
 fmt.Println(word_wrap(unicodeStrWithDoubleSpaces, 5))

 longTextStr := "KUALA LUMPUR: The FBM KLCI and key Asian markets were in the red at the midday on Monday but off the day’s worst on some buying support at lower levels while China’s markets and the yuan managed to find a steadier footing. At 12.30pm, the KLCI was down 9.43 point or 0.58% to 1,619.12 with 24 out of the 30 stocks in the red. Turnover was 1.32 billion shares valued at RM855.53mil. However, the broader market was much weaker with decliners beating advancers more than eight to one with 819 losers to 105 gainers while 203 counters were unchanged. China stocks opened sharply lower on Monday but managed to erase much of the losses by midday, with real estate shares reversing initial declines on data showing continuous recovery in the property sector, Reuters report. Hong Kong shares dropped, with investors' risk appetites soured by resumed declines in oil prices as well as Friday's tumbles for equities prices in US and European markets. US light crude oil fell 23 cents to US$29.19 and Brent lost 27 cents to US$28.67. Petronas Gas was the top loser, down 38 sen to RM21.08 and erased 1.25 points from the KLCI, Petronas Dagangan fell 18 sen to RM23.72 but Petronas Chemicals rose three sen to RM7.03. SapuraKencana shed two sen to RM1.66. Refiners Shell and Petron Malaysia were among the top losers, Shell was down 29 sen to RM5.23 and  Petron lost 26 sen to RM6.17.Crude palm oil for third-month delivery rose RM26 to RM2,490. Genting Plantations added 14 sen to RM10.36 while PPB Group rose six sen to RM15.78. IOI Corp was flat at RM4.32, KL Kepong fell 18 sen to RM22.68 and Sime Darby three sen to RM7.09. "

 fmt.Printf("Original : [%v] \n", longTextStr)
 fmt.Println("--------------------------------")

 // limit to 11 words per line
 fmt.Println(word_wrap(longTextStr, 11))

 }

Output:

Original : [Here is a nice text string consisting of eleven words.]

Here is a

nice text string

consisting of eleven

words.


Original : [This code example will attempt to word warp this text string - 'Here is a nice text string consisting of eleven words.']

This code example will attempt to word

warp this text string - 'Here is

a nice text string consisting of eleven

words.'


Original : [Here is a nice text string consisting of eleven words and some unicode characters such as 世界你好.]

Here is a nice text

string consisting of eleven words

and some unicode characters such

as 世界你好.


Original : [KUALA LUMPUR: The FBM KLCI and key Asian markets were in the red at the midday on Monday but off the day’s worst on some buying support at lower levels while China’s markets and the yuan managed to find a steadier footing. At 12.30pm, the KLCI was down 9.43 point or 0.58% to 1,619.12 with 24 out of the 30 stocks in the red. Turnover was 1.32 billion shares valued at RM855.53mil. However, the broader market was much weaker with decliners beating advancers more than eight to one with 819 losers to 105 gainers while 203 counters were unchanged. China stocks opened sharply lower on Monday but managed to erase much of the losses by midday, with real estate shares reversing initial declines on data showing continuous recovery in the property sector, Reuters report. Hong Kong shares dropped, with investors' risk appetites soured by resumed declines in oil prices as well as Friday's tumbles for equities prices in US and European markets. US light crude oil fell 23 cents to US$29.19 and Brent lost 27 cents to US$28.67. Petronas Gas was the top loser, down 38 sen to RM21.08 and erased 1.25 points from the KLCI, Petronas Dagangan fell 18 sen to RM23.72 but Petronas Chemicals rose three sen to RM7.03. SapuraKencana shed two sen to RM1.66. Refiners Shell and Petron Malaysia were among the top losers, Shell was down 29 sen to RM5.23 and Petron lost 26 sen to RM6.17.Crude palm oil for third-month delivery rose RM26 to RM2,490. Genting Plantations added 14 sen to RM10.36 while PPB Group rose six sen to RM15.78. IOI Corp was flat at RM4.32, KL Kepong fell 18 sen to RM22.68 and Sime Darby three sen to RM7.09. ]


KUALA LUMPUR: The FBM KLCI and key Asian markets were in

the red at the midday on Monday but off the day’s

worst on some buying support at lower levels while China’s markets

and the yuan managed to find a steadier footing. At 12.30pm,

the KLCI was down 9.43 point or 0.58% to 1,619.12 with

24 out of the 30 stocks in the red. Turnover was

1.32 billion shares valued at RM855.53mil. However, the broader market was

much weaker with decliners beating advancers more than eight to one

with 819 losers to 105 gainers while 203 counters were unchanged.

China stocks opened sharply lower on Monday but managed to erase

much of the losses by midday, with real estate shares reversing

initial declines on data showing continuous recovery in the property sector,

Reuters report. Hong Kong shares dropped, with investors' risk appetites soured

by resumed declines in oil prices as well as Friday's tumbles

for equities prices in US and European markets. US light crude

oil fell 23 cents to US$29.19 and Brent lost 27 cents

to US$28.67. Petronas Gas was the top loser, down 38 sen

to RM21.08 and erased 1.25 points from the KLCI, Petronas Dagangan

fell 18 sen to RM23.72 but Petronas Chemicals rose three sen

to RM7.03. SapuraKencana shed two sen to RM1.66. Refiners Shell and

Petron Malaysia were among the top losers, Shell was down 29

sen to RM5.23 and Petron lost 26 sen to RM6.17.Crude palm

oil for third-month delivery rose RM26 to RM2,490. Genting Plantations added

14 sen to RM10.36 while PPB Group rose six sen to

RM15.78. IOI Corp was flat at RM4.32, KL Kepong fell 18

sen to RM22.68 and Sime Darby three sen to RM7.09.

  See also : Golang : Word limiter example



Tags : golang line-break word-wrap slice-string

By Adam Ng

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