mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 21:10:12 +01:00
33110d096c
* Rewrite constraints are stored in a facet type, substituted, imported, and formatted. * We now distinguish `.Self` from other symbolic bindings in two ways: * `.Self` itself now has an invalid compile time binding index (since it doesn't bind to any of the generic parameters). As a result, we no longer need to create a generic region in `handle_where.cpp`. * There is a new phase tracking values that are only symbolic because they transitively depend on `.Self`. This allows us to give the result of a `where` expression template phase as long as it doesn't use any symbolic constants other than `.Self` or other designators. * `AddConstant` has been removed from `check/context` since it was only used from `eval`. This meant less plumbing of the phase change. * Evaluation of `BindSymbolicName` now also performs substitution into its type. * Include a bit more information in some diagnostics. * `StringifyTypeExpr` outputs rewrites, which required adding support for associated entities as well. * Associated entities now have an entity name set when importing. * Adds tests for some interesting cases with rewrites and uses of `.Self` mixed with other symbolic constants. Still to do: * There is no validation that any particular type satisfies rewrite constraints. * Access to members of a facet type do not see the rewritten values. * Impls don't recognize whether associated constants have rewrites setting their values. * No support for resolving facet types. --------- Co-authored-by: Josh L <josh11b@users.noreply.github.com> Co-authored-by: Richard Smith <richard@metafoo.co.uk>