Function EatSameChars

src/butil/strings/string_util.cc:733–773

// Move the strings pointers to the point where they start to differ.
template <typename CHAR, typename NEXT>
static void EatSameChars(const CHAR** pattern, const CHAR* pattern_end,
                         const CHAR** string, const CHAR* string_end,
                         NEXT next) {
  const CHAR* escape = NULL;
  while (*pattern != pattern_end && *string != string_end) {
    if (!escape && IsWildcard(**pattern)) {
      // We don't want to match wildcard here, except if it's escaped.
      return;
    }

    // Check if the escapement char is found. If so, skip it and move to the
    // next character.
    if (!escape && **pattern == '\\') {
      escape = *pattern;
      next(pattern, pattern_end);
      continue;
    }

    // Check if the chars match, if so, increment the ptrs.
    const CHAR* pattern_next = *pattern;
    const CHAR* string_next = *string;
    base_icu::UChar32 pattern_char = next(&pattern_next, pattern_end);
    if (pattern_char == next(&string_next, string_end) &&
        pattern_char != (base_icu::UChar32) CBU_SENTINEL) {
      *pattern = pattern_next;
      *string = string_next;
    } else {
      // Uh ho, it did not match, we are done. If the last char was an
      // escapement, that means that it was an error to advance the ptr here,
      // let's put it back where it was. This also mean that the MatchPattern
      // function will return false because if we can't match an escape char
      // here, then no one will.
      if (escape) {
        *pattern = escape;
      }
      return;
    }

    escape = NULL;
  }
}

template <typename CHAR, typename NEXT>
static void EatWildcard(const CHAR** pattern, const CHAR* end, NEXT next) {