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| 1 | namespace Semantic.Types is | |
| 2 | ||
| 3 | use Source.LOCATION; | |
| 4 | ||
| 5 | // `Ghul.MAYBE[T]` — the runtime's unconstrained-T optional | |
| 6 | // carrier. is_maybe drives the implicit conversion to `T?` at | |
| 7 | // slot boundaries; surfacing it as a distinct GENERIC subclass | |
| 8 | // means recognition is a virtual-property check (no per-call | |
| 9 | // symbol lookup, and source-side MAYBE structs inside | |
| 10 | // `ghul-runtime`'s own compile stay as plain GENERIC where the | |
| 11 | // conversion is correctly inactive). | |
| 12 | class MAYBE: GENERIC is | |
| 13 | is_maybe: bool => true; | |
| 14 | ||
| 15 | is_optional: bool => true; | |
| 16 | ||
| 17 | optional_inner_type: Type? => arguments[0]; | |
| 18 | ||
| 19 | short_description: string => get_short_description(self); | |
| 20 | ||
| 21 | get_short_description(reference: GENERIC) -> string static => "{reference.arguments[0].short_description}?"; | |
| 22 | ||
| 23 | init( | |
| 24 | location: LOCATION, | |
| 25 | symbol: Symbols.Classy, | |
| 26 | arguments: Collections.List[Type] | |
| 27 | ) is | |
| 28 | super.init(location, symbol, arguments); | |
| 29 | si | |
| 30 | ||
| 31 | create( | |
| 32 | location: LOCATION, | |
| 33 | symbol: Symbols.Classy, | |
| 34 | arguments: Collections.List[Type] | |
| 35 | ) -> GENERIC => | |
| 36 | Types.MAYBE(location, symbol, arguments); | |
| 37 | ||
| 38 | // MAYBE[T] accepts a value of T via the implicit T -> T? widening, | |
| 39 | // the same rule NULLABLE uses: the boxer emits a MAYBE<T>::.ctor | |
| 40 | // wrap at the slot boundary. Reported as ASSIGNABLE, not SAME, so | |
| 41 | // an overload resolver with both f(T) and f(T?) candidates and a T | |
| 42 | // argument still prefers f(T). Shares NULLABLE's helper — both are | |
| 43 | // value-type optional carriers with a single-argument present-value | |
| 44 | // constructor. | |
| 45 | compare(other: Type) -> Types.MATCH => | |
| 46 | Types.NULLABLE.compare_optional(self, other, super.compare(other)); | |
| 47 | ||
| 48 | to_string() -> string => "{arguments[0]}?"; | |
| 49 | si | |
| 50 | si |