carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-06 06:34:41 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Make built-in conversions visible to ImplicitAs. (#2525)

Browse Source 
Add a blanket `ImplicitAs` implementation to perform the conversions that explorer can perform as built-in conversions. This allows those conversions to be detected by constraints and to be used as part of other user-defined conversions. For now, a single monolithic conversion is exposed. I intend to split this up into multiple smaller conversion kinds for each kind of conversion in a follow-up change.

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This commit is contained in:
Richard Smith
2023-01-18 17:36:55 -08:00
committed by GitHub
co-authored by Jon Ross-Perkins
parent 94872ef6da
commit 0d279b388a
13 changed files with 319 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files
explorer/interpreter/interpreter.cpp
+36
View File
@@ -1467,6 +1467,42 @@ auto Interpreter::StepExp() -> ErrorOr<Success> {
int r = (generator() % (high - low)) + low;
return todo_.FinishAction(arena_->New<IntValue>(r));
}
case IntrinsicExpression::Intrinsic::ImplicitAs: {
CARBON_CHECK(args.size() == 1);
// Build a constraint type that constrains its .Self type to satisfy
// the "ImplicitAs" intrinsic constraint. This involves creating a
// number of objects that all point to each other.
// TODO: Factor out a simple version of ConstraintTypeBuilder and use
// it from here.
auto* self_binding = arena_->New<GenericBinding>(
exp.source_loc(), ".Self",
arena_->New<TypeTypeLiteral>(exp.source_loc()));
auto* self = arena_->New<VariableType>(self_binding);
auto* impl_binding = arena_->New<ImplBinding>(
exp.source_loc(), self_binding, std::nullopt);
impl_binding->set_symbolic_identity(
arena_->New<BindingWitness>(impl_binding));
self_binding->set_symbolic_identity(self);
self_binding->set_value(self);
self_binding->set_impl_binding(impl_binding);
IntrinsicConstraint constraint = {
.type = self,
.kind = IntrinsicConstraint::ImplicitAs,
.arguments = args};
auto* result = arena_->New<ConstraintType>(
self_binding, std::vector<ImplConstraint>{},
std::vector<IntrinsicConstraint>{std::move(constraint)},
std::vector<EqualityConstraint>{},
std::vector<RewriteConstraint>{}, std::vector<LookupContext>{});
impl_binding->set_interface(result);
return todo_.FinishAction(result);
}
case IntrinsicExpression::Intrinsic::ImplicitAsConvert: {
CARBON_CHECK(args.size() == 2);
CARBON_ASSIGN_OR_RETURN(Nonnull<const Value*> result,
Convert(args[0], args[1], exp.source_loc()));
return todo_.FinishAction(result);
}
case IntrinsicExpression::Intrinsic::IntEq: {
CARBON_CHECK(args.size() == 2);
auto lhs = cast<IntValue>(*args[0]).value();