SYS-UTFBYTES(2) System Calls Manual SYS-UTFBYTES(2)

utfbytes - compute UTF length of complete Unicode characters in a UTF byte sequence

include "sys.m";
sys := load Sys Sys->PATH;
utfbytes: fn(buf: array of byte, n: int): int;

Utfbytes examines the n-byte UTF sequence in buf and returns the number of bytes representing complete Unicode characters. The value will be less than n when the region inspected ends with an incomplete UTF sequence.

A bounds check error results if n exceeds the length of the array.

sys-intro (2), sys-byte2char (2), utf (6)