evaluateNumber method
Implementation
bool evaluateNumber(num? left, String operator, num right) {
switch (operator) {
case '=' || '==':
return left == right;
case '<>' || '!=':
return left != right;
case '>':
return left == null || left > right;
case '=>' || '>=':
return left == null || left >= right;
case '<':
return left != null && left < right;
case '=<' || '<=':
return left != null && left <= right;
}
throw UnimplementedError();
}