in lib/src/comparators.dart [224:246]
int compareAsciiUpperCaseNatural(String a, String b) {
var defaultResult = 0;
for (var i = 0; i < a.length; i++) {
if (i >= b.length) return 1;
var aChar = a.codeUnitAt(i);
var bChar = b.codeUnitAt(i);
if (aChar == bChar) continue;
var aUpperCase = aChar;
var bUpperCase = bChar;
if (_lowerCaseA <= aChar && aChar <= _lowerCaseZ) {
aUpperCase -= _asciiCaseBit;
}
if (_lowerCaseA <= bChar && bChar <= _lowerCaseZ) {
bUpperCase -= _asciiCaseBit;
}
if (aUpperCase != bUpperCase) {
return _compareNaturally(a, b, i, aUpperCase, bUpperCase);
}
if (defaultResult == 0) defaultResult = aChar - bChar;
}
if (b.length > a.length) return -1;
return defaultResult.sign;
}