> On Jul 4, 2016, at 9:29 AM, Josef Willsher via swift-dev > <swift-dev@swift.org> wrote: > > Hi everyone, > > I’ve been implementing SE-0095 (here) and have hit an issue around how > Any.self is treated. > > When in the type position, I parse Any like any other type, and resolve it to > be an empty protocol composition in the constraint system, in > resolveTopLevelTypeComponent. > > This does not work for metatype lookup, where the lookup is unconstrained and > I need to find a ValueDecl for the Any type. Currently I have kept the > stdlib’s typealias Any = protocol<> so the type system can look to the stdlib > through getAnyDecl to find it. Does anyone have an idea about how this could > be done without this; there are no other keywords that need this sort of > unconstrained lookup and are implicitly declared?
A ValueDecl for a type shouldn't be required for a metatype expression, since something like (Int, String).self or (() -> ()).self ought to work too. Type resolution ought to handle this by turning the subexpression into a TypeExpr before we do type checking; see PreCheckExpression::simplifyTypeExpr. > Another question I had: does SE-0095 extend to SIL syntax? The proposal > does’t mention it, but I think it would seem out of place to keep the > protocol<> pattern in .sil if we are replacing it in .swift, the AST, and the > demangler. SIL mostly reuses Swift's type syntax, so this should fall out. You will want to ensure the demangler and the runtime use the new syntax when printing metatype values. -Joe _______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev
