From 367edf757aff609b72de48732113ea756d878f52 Mon Sep 17 00:00:00 2001 From: Tim Foley Date: Thu, 15 Jun 2017 11:16:10 -0700 Subject: Add basic support for `interface` declarations - Add a test case for `interface` declarations and the exected implicit type conversion rules around them - Rename exising "trait" declaration kind to "interface" - There was already basic syntax for `__trait` declarations, and a bunch of related machinery. - Not all of it worked as needed, but it was clearly a start at solving the problem - Change `InterfaceConformanceDecl` to a more general `InheritanceDecl` that covers inheritance from any type expression (leave it to other code to validate the cases that should be allowed) - Instead of keeping a raw `bases` array on interface/trait declarations, turn all inheritance clauses into `IheritanceDecl` members - Add support for inheritance clause on `struct` types - Remove the `__conforms` syntax only used in the stdlib, in favor of conentional `: Base` style syntax already in place for aggregate types - Make sure that the parser pushes a new scope around he member declarations of an aggregate type, so that lookup in member functions will correctly find members of the enclosing type - In `TryCoerceImpl`, allow a type that conforms to an interface to be implicitly conveted to the corresponding interface type. This leaves out a lot of major functionality: - There is no validation that a type provides all the members it is supposed to as part of fulfilling a claimed interface conformance - The lookup process needs to deal with inherited members at some point. - We can avoid this for now if we don't allow inheritance for concrete types - When it comes time to handle it, it *might* be possible to implement by considering an `InheritanceDecl` to be, conceptually, a member of the inherited type, with a `__transparent` modifier - The lookup rules member functions do *not* deal with a lot of stuff: - There is no `this` expression right now - The semantic checker does not rewrite `foo` to `this.foo`, so downstream stages aren't going to get things in a clean format - There is no handling of mutability currently - The right answer there is probably to make member functions on `struct` types non-mutating by default, and add a qualifier to opt in to mutability. I believe this is actually what the OOP syntax in HLSL did way back when. - There is no handling of `static` members, and thus no checking to make sure that non-static members aren't referenced in static functions - None of this affects down-stream code generation right now, so it probably won't actually produce anything valid. - This is where we start needing a suitable IR to use for lowering, to manage the complexity. --- source/slang/syntax.cpp | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'source/slang/syntax.cpp') diff --git a/source/slang/syntax.cpp b/source/slang/syntax.cpp index fffc6c725..e47c610c0 100644 --- a/source/slang/syntax.cpp +++ b/source/slang/syntax.cpp @@ -1311,19 +1311,19 @@ namespace Slang return visitor->VisitDefaultStmt(this); } - // TraitDecl + // InterfaceDecl - RefPtr TraitDecl::Accept(SyntaxVisitor * visitor) + RefPtr InterfaceDecl::Accept(SyntaxVisitor * visitor) { - visitor->VisitTraitDecl(this); + visitor->visitInterfaceDecl(this); return this; } - // TraitConformanceDecl + // InheritanceDecl - RefPtr TraitConformanceDecl::Accept(SyntaxVisitor * visitor) + RefPtr InheritanceDecl::Accept(SyntaxVisitor * visitor) { - visitor->VisitTraitConformanceDecl(this); + visitor->visitInheritanceDecl(this); return this; } -- cgit v1.2.3