hasCodeLikeToken function

bool hasCodeLikeToken(String value)

Returns true when any whitespace-delimited token mixes letters and digits.

This identifies code-like fields such as invoice numbers, SKUs, and IDs without treating ordinary prose lines that merely contain a separate number token as mixed-format. Short merged column values like B1 in receipt rows are excluded so they do not suppress sentence casing for the whole line.

Implementation

bool hasCodeLikeToken(String value) {
  for (final String token in value.split(RegExp(r'\s+'))) {
    if (token.isEmpty) {
      continue;
    }

    final String compact = token.replaceAll(RegExp(r'[^A-Za-z0-9]'), '');
    if (compact.isEmpty) {
      continue;
    }

    bool hasLetter = false;
    bool hasDigit = false;
    int letters = 0;
    int digits = 0;
    for (int i = 0; i < compact.length; i++) {
      final int code = compact.codeUnitAt(i);
      if (isLetter(code)) {
        hasLetter = true;
        letters++;
      } else if (isDigit(code)) {
        hasDigit = true;
        digits++;
      }
    }

    final bool looksLikeCode =
        hasLetter &&
        hasDigit &&
        compact.length >= _codeLikeTokenMinCompactLength &&
        (letters >= _codeLikeTokenMinLetterOrDigitCount ||
            digits >= _codeLikeTokenMinLetterOrDigitCount);
    if (looksLikeCode) {
      return true;
    }
  }

  return false;
}