RUNENORM(2)                                           RUNENORM(2)

     NAME
          runedecomp, runerecomp, runenorm, utfnorm, fullrunenorm,
          fullutfnorm, runegbreak, runewbreak - multi-rune graphemes

     SYNOPSIS
          #include <u.h>
          #include <libc.h>

          void   runedecomp(Rune dst[2], Rune src)

          Rune   runerecomp(Rune r[2])

          int    runenorm(Rune *dst, Rune *src, int max, int compose)

          int    utfnorm(char *dst, char *src, int max, int compose)

          Rune*  fullrunenorm(Rune *s, int n)

          char*  fullutfnorm(char *s, int n)

          Rune*  runegbreak(Rune *r)

          Rune*  runewbreak(Rune *r)

     DESCRIPTION
          These routines help in handling graphemes that may span mul-
          tiple runes.

          Runedecomp decomposes the rune src and places the two decom-
          posed runes into dst. If no decomposition is found dst is
          zeroed.

          Runerecomp composes the two runes provided in r and returns
          the result. If no composition is found 0 is returned.

          Runenorm (Utfnorm) copies the rune (UTF) sequence src to dst
          while performing Unicode normalization.  No more then max
          runes (bytes) will be copied, and the result is always null
          terminated. If compose is non-zero NFC normalization is per-
          formed, otherwise NFD normalization is performed.

          Fullrunenorm (fullutfnorm) determines if enough runes
          (bytes) are present in s to perform normalization. If enough
          is present, a pointer is returned to the first rune (byte)
          that begins the next context, otherwise s is returned. No
          more then n runes (bytes) will be read.

          Runegbreak (Runewbreak) searches r for the next grapheme
          (word) break opportunity. If none are found before the end
          of the string r is returned.

     SOURCE
          /sys/src/libc/port/mkrunetype.c
          /sys/src/libc/port/runenorm.c
          /sys/src/libc/port/runebreak.c

     SEE ALSO
          Unicode® Standard Annex #15
          Unicode® Standard Annex #29
          rune(2), utf(6), tcs(1)