slang.git - Making it easier to work with shaders

Age	Commit message (Collapse)	Author
2020-08-20	Initial support for a using construct (#1506)	Tim Foley
	The basic idea is that if you have a namespace: namespace MyCoolNamespace { void f() { ... } ... } then you can bring the declarations from that namespace into scope with: using MyCoolNamespace; f(); The `using` construct is allowed in any scope where declarations are allowed. As an additional feature, the construct allows and then ignores the keyword `namespace` if it occurs right after `using`: using namespace MyCoolNamespace; Note that unlike in C++, `using` a namespace inside another namespace doesn't implicitly make the symbols available to clients of that namespace: namespace hidden { void secret() {...} ... } namespace api { using hidden; ... } api.secret(); // ERROR: `secret()` isn't a member of `api` The implementation of this feature was relatively simple, although it does leave out more advanced features that might be desirable in the future: * No support for `using MCN = MyCoolNamespace` sorts of tricks to define a short name * No support for `using` anything that isn't a namespace (e.g., to make the members of a type available without qualification) * No support for cases where multiple visible modules have a namespace of the same name (or dealing with overloaded namespaces in general)
2020-04-02	Add basic support for namespaces (#1304)	Tim Foley
	This change adds logic for parsing `namespace` declarations, referencing them, and looking up their members. * The parser changes are a bit subtle, because that is where we deal with the issue of "re-opening" a namespace. We kludge things a bit by re-using an existing `NamespaceDecl` in the same parent if one is available, and thereby ensure that all the members in the same namespace can see on another. * In order to allow namespaces to be referenced by name they need to have a type so that a `DeclRefExpr` to them can be formed. For this purpose we introduce `NamespaceType` which is the (singleton) type of a reference to a given namespace. * The new `NamespaceType` case is detected in the `MemberExpr` checking logic and routed to the same logic that `StaticMemberExpr` uses, and the static lookup logic was extended with support for looking up in a namespace (a thin wrapper around one of the existing worker routines in `slang-lookup.cpp`. * I made `NamespaceDecl` have a shared base class with `ModuleDecl` in the hopes that this would allow us to allow references to modules by name in the future. That hasn't been tested as part of this change. * I cleaned up a bunch of logic around `ModuleDecl` holding a `Scope` pointer that was being used for some of the more ad hoc lookup routines in the public API. Those have been switched over to something that is a bit more sensible given the language rules and that doesn't rely on keeping state sititng around on the `ModuleDecl`. * I added a test case to make sure the new funcitonality works, which includes re-opening a namespace, and it also tests both `.` and `::` operations for lookup in a namespace. * The main missing feature here is the ability to do something like C++ `using`. It would probably be cleanest if we used `import` for this, since we already have that syntax (and having both `import` and `using` seems like a recipe for confusion). Most of the infrastructure is present to support `import`ing one namespace into another (in a way that wouldn't automatically pollute the namespace for clients), but some careful thought needs to be put into how import of namespaces vs. modules should work.