---

Manual Reference Pages  - codepoints_to_utf8 (3m_unicode)

---

NAME

CODEPOINTS_TO_UTF8(3f) - [M_unicode:CONVERSION] convert codepoints to CHARACTER (LICENSE:MIT)

CONTENTS

Synopsis
Characteristics
Description
Options
Examples
See Also
Author
License

SYNOPSIS

pure subroutine codepoints_to_utf8(codepoints,utf8,nerr)

    integer,allocatable,intent(in) :: codepoints(:)
    !
    character(len=1),intent(out)   :: utf8(:)
    !  or
    character(len=*),intent(out)   :: utf8
    !
    integer,intent(out)            :: nerr

CHARACTERISTICS

o	UTF8 is a scalar or array CHARACTER variable
o	CODEPOINTS is of default INTEGER kind
o	NERR is of default INTEGER kind

DESCRIPTION

CODEPOINTS_TO_UTF8(3f) takes an integer array of Unicode codepoint values and generates either a scalar CHARACTER variable or an array of bytes (AKA. CHARACTER(LEN=1)) which are assumed to contain a stream of bytes representing UTF-8-encoded data.

OPTIONS

o	CODEPOINTS : An INTEGER array of Unicode codepoint values representing the glyphs to be encoded at UTF-8 data
o	UTF8 : Scalar or single-character array CHARACTER variables to contain a stream of bytes containing data encoded at UTF-8 text.
o	NERR : Zero if no error occurred. If not zero the stream of bytes could not be completely converted to UTF-8 characters.

EXAMPLES

Sample program

   program demo_codepoints_to_utf8
   use m_unicode, only : codepoints_to_utf8
   implicit none
   !’Noho me ka hau’oli’ !(Be happy)
   integer,parameter :: codepoints(*)=[ &
      & 78,111,104,111,&
      & 32,109,101, &
      & 32,107,97, &
      & 32,104,97,117,8217,111,108,105]
   character(len=:),allocatable :: string
   character(len=1),allocatable :: bytes(:)
   character(len=*),parameter   :: solid=’(*(g0))’
   character(len=*),parameter   :: space=’(*(g0,1x))’
   character(len=*),parameter   :: z=’(a,*(z0,1x))’
   integer                      :: nerr
   ! BASIC USAGE: SCALAR CHARACTER VARIABLE
     write(*,space)’CODEPOINTS:’, codepoints
     write(*,z)’HEXADECIMAL CODEPOINTS:’, codepoints
     call codepoints_to_utf8(codepoints,string,nerr)
     write(*,solid)’STRING:’,string
   !
     write(*,space)’How long is this string in glyphs? ’
     write(*,space)size(codepoints)
     write(*,space)’How long is this string in bytes? ’
     write(*,space)len(string)
   !
   ! BASIC USAGE: ARRAY OF BYTES
     call codepoints_to_utf8(codepoints,bytes,nerr)
     write(*,solid)’STRING:’,bytes
   !
     write(*,space)’How long is this string in glyphs? ’
     write(*,space)size(codepoints)
     write(*,space)’How long is this string in bytes? ’
     write(*,space)size(bytes)
   !
   end program demo_codepoints_to_utf8

Results:

    > CODEPOINTS: 78 111 104 111 32 109 101 32 107 97 32 104 97 117 ...
    > 8217 111 108 105
    > 48 4E 6F 68 6F 20 6D 65 20 6B 61 20 68 61 75 2019 6F 6C 69
    > STRING:Noho me ka hau’oli
    > How long is this string in glyphs?
    > 18
    > How long is this string in bytes?
    > 20
    > STRING:Noho me ka hau’oli
    > How long is this string in glyphs?
    > 18
    > How long is this string in bytes?
    > 20

SEE ALSO

functions that perform operations on character strings:

o	elemental: adjustl(3), adjustr(3), index(3), scan(3), verify(3)
o	non-elemental: len_trim(3), repeat(3), trim(3), codepoints_to_utf8(3), utf8_to_codepoints(3)

AUTHOR

o	John S. Urban
o	Francois Jacq - enhancements from Francois Jacq, 2025-08

LICENSE

    MIT

---