/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-â
âvi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :viâ
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â This is free and unencumbered software released into the public domain.      â
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#include "libc/str/str.h"

/**
 * Extracts non-empty tokens from string.
 *
 * @param s is mutated and should be NULL on subsequent calls
 * @param sep is a NUL-terminated set of wchars to consider separators
 * @param state tracks progress between calls
 * @return pointer to next token or NULL for end
 */
wchar_t *wcstok(wchar_t *s, const wchar_t *sep, wchar_t **state) {
  size_t leadingseps, tokenlen;
  if (!s) {
    s = *state;
    if (!s) {
      return NULL;
    }
  }
  leadingseps = wcsspn(s, sep);
  s += leadingseps;
  if (*s) {
    tokenlen = wcscspn(s, sep);
    if (s[tokenlen]) {
      s[tokenlen] = L'\0';
      *state = &s[tokenlen + 1];
      return s;
    } else if (tokenlen) {
      s[tokenlen] = L'\0';
      *state = NULL;
      return s;
    }
  }
  return (*state = NULL);
}
