| 1 | | | import 'converter.dart'; |
| 2 | | | |
| 3 | | | final class NumConverter extends Converter { |
| 4 | | 11 | const NumConverter(); |
| 5 | | | |
| 6 | | | static const instance = NumConverter(); |
| 7 | | | |
| 8 | | 1 | @override |
| 9 | | 3 | Cast<T> value<T>() => _numCastors[T] as Cast<T>? ?? Converter.identity<T>; |
| 10 | | | |
| 11 | | 2 | static int _toInt(dynamic x) { |
| 12 | | 3 | if (x is int && x.isFinite) return x; |
| 13 | | 2 | final y = (x as num).toDouble(); |
| 14 | | 2 | if (!y.isFinite) return double.nan as int; // intended type error |
| 15 | | 3 | final z = y.toInt(), d = y - z; |
| 16 | | 2 | if (d != 0) return double.nan as int; // intended type error |
| 17 | | 0 | return z; |
| 18 | | 1 | } |
| 19 | | | |
| 20 | | 3 | static double _toDbl(dynamic x) => (x as num).toDouble(); |
| 21 | | | |
| 22 | | 4 | static final Map<Type, Cast> _numCastors = { |
| 23 | | 1 | int: _toInt, |
| 24 | | 1 | double: _toDbl, |
| 25 | | | }; |
| 26 | | | } |