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| 1 | namespace Syntax.Process is | |
| 2 | // A generic alias named without type arguments, where a type is | |
| 3 | // wanted as a value - most often to construct it. An alias that | |
| 4 | // renames a generic class, passing its own type parameters through in | |
| 5 | // order, stands for that class, so its type arguments are inferred as | |
| 6 | // they would be for the class. Any other generic alias has no single | |
| 7 | // class to infer them for. | |
| 8 | class BARE_GENERIC_ALIAS is | |
| 9 | // The class the alias renames, as its open type, or null when the | |
| 10 | // alias does anything more than rename. | |
| 11 | class_type(alias: Semantic.Symbols.TYPE_ALIAS) -> Semantic.Types.Type? static is | |
| 12 | let target = cast Semantic.Types.GENERIC?(alias.target_type) | |
| 13 | ||
| 14 | if !target? then | |
| 15 | return null | |
| 16 | fi | |
| 17 | ||
| 18 | let arguments = target.arguments | |
| 19 | let parameters = alias.type_parameters | |
| 20 | ||
| 21 | if arguments.count != parameters.count then | |
| 22 | return null | |
| 23 | fi | |
| 24 | ||
| 25 | for i in 0..arguments.count do | |
| 26 | let argument = cast Semantic.Types.NAMED?(arguments[i]) | |
| 27 | ||
| 28 | if !argument? \/ argument.symbol != cast Semantic.Symbols.Symbol(parameters[i]) then | |
| 29 | return null | |
| 30 | fi | |
| 31 | od | |
| 32 | ||
| 33 | if let generic = cast Semantic.Symbols.GENERIC?(target.symbol) then | |
| 34 | return generic.symbol.type | |
| 35 | fi | |
| 36 | ||
| 37 | return null | |
| 38 | si | |
| 39 | si | |
| 40 | si |