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| 1 | namespace Semantic is | |
| 2 | use Types.Type | |
| 3 | ||
| 4 | // System.Decimal declares a conversion for each of the fixed-width | |
| 5 | // integers but none for a pointer-sized one, so a cast between the | |
| 6 | // two has no single step to take. It goes through the 64-bit integer | |
| 7 | // of the same signedness, which Decimal does declare a conversion | |
| 8 | // for and which a `conv` opcode reaches from the pointer-sized type. | |
| 9 | // | |
| 10 | // Held apart from the casting itself because the rule is consulted | |
| 11 | // twice - once to decide the cast is legal and once to perform it - | |
| 12 | // and the two answers have to be the same one. | |
| 13 | class POINTER_SIZED_DECIMAL_BRIDGE(_innate_symbol_lookup: Lookups.InnateSymbolLookup) is | |
| 14 | super() | |
| 15 | ||
| 16 | // The type to convert through, or null when the pair needs no | |
| 17 | // bridge. Null for a pair that is already one step, and null | |
| 18 | // once either side is the bridge type itself, which is what | |
| 19 | // stops the two-step from reapplying to its own halves. | |
| 20 | find(source: Type?, target: Type?) -> Type? is | |
| 21 | if !source? \/ !target? then | |
| 22 | return null | |
| 23 | fi | |
| 24 | ||
| 25 | let decimal_type = _innate_symbol_lookup.get_decimal_type() | |
| 26 | ||
| 27 | let source_is_decimal = source.matches(decimal_type) | |
| 28 | let target_is_decimal = target.matches(decimal_type) | |
| 29 | ||
| 30 | if source_is_decimal == target_is_decimal then | |
| 31 | return null | |
| 32 | fi | |
| 33 | ||
| 34 | let other = if source_is_decimal then target else source fi | |
| 35 | ||
| 36 | if other.matches(_innate_symbol_lookup.get_word_type()) then | |
| 37 | return _innate_symbol_lookup.get_long_type() | |
| 38 | fi | |
| 39 | ||
| 40 | if other.matches(_innate_symbol_lookup.get_uword_type()) then | |
| 41 | return _innate_symbol_lookup.get_ulong_type() | |
| 42 | fi | |
| 43 | ||
| 44 | return null | |
| 45 | si | |
| 46 | si | |
| 47 | si |