mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 21:40:12 +01:00
Dana Jansens
917a6ea971
Currently each interface has a `Self` facet internally that becomes a binding to every entity inside the interface: associated constants, functions, and require decls. Each of these has to be independently generic as a result. This makes is challenging in extended name lookup to move into an extended scope of an interface, as we have a specific for the interface, but the names within require a different specific that includes a `Self` facet value. We generalize this relationship by adding a second generic to Interface, called `generic_with_self`. When we want to work with entities inside the interface, we move from the interface-without-specific to the interface-with-self specific by adding a Self to the specific. This is done independently of any particular entity inside the Interface, as those entities are now all members of the interface-with-self generic. Associated constants no longer need a generic of their own, as they do not have separate generic bindings. Functions retain a generic, but if the function has no generic arguments, it will have no bindings of its own now. Require decls retain a generic so that their specific can be instantiated separately from the interface. Requiring the interface to be complete does not require the types in a require decl to be complete unless it is modified by `extend`. So we allow them to be completed later by keeping them in a separate generic. Named constraints look like interfaces and gain the additional inner generic-with-self, with the same relationship to require decls. This removes the need for name lookup to perform Substitution of a Self facet into the extended scope instruction. Instead, the `SpecificConstant` instruction inserted by a `require` decl is part of the interface-with-self generic. When looking through a FacetType for extended scopes, for each interface, we push the scope with the specific for the interface-with-self. Then the constant value of the `SpecificConstant` is correctly modified by the provided self automatically through applying that specific.
71 lines
2.6 KiB
C++
71 lines
2.6 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
|
|
#ifndef CARBON_TOOLCHAIN_SEM_IR_INTERFACE_H_
|
|
#define CARBON_TOOLCHAIN_SEM_IR_INTERFACE_H_
|
|
|
|
#include "toolchain/base/value_store.h"
|
|
#include "toolchain/sem_ir/entity_with_params_base.h"
|
|
#include "toolchain/sem_ir/ids.h"
|
|
|
|
namespace Carbon::SemIR {
|
|
|
|
// Interface-specific fields.
|
|
//
|
|
// TODO: Factor out the shared fields between InterfaceFields and
|
|
// NamedConstraintFields.
|
|
struct InterfaceFields {
|
|
// The following members are set at the `{` of the interface definition.
|
|
|
|
// The interface scopes.
|
|
NameScopeId scope_without_self_id = NameScopeId::None;
|
|
NameScopeId scope_with_self_id = NameScopeId::None;
|
|
// The block of instructions outside the interface-with-self. This is where
|
|
// the `Self` instruction can be constructed.
|
|
InstBlockId body_block_without_self_id = InstBlockId::None;
|
|
// The interface-with-self generic, where the `Self` is a parameter to the
|
|
// generic. This generic contains all the associated entities of the
|
|
// interface.
|
|
GenericId generic_with_self_id = GenericId::None;
|
|
// The first block of the interface-with-self body.
|
|
// TODO: Handle control flow in the interface body, such as if-expressions.
|
|
InstBlockId body_block_with_self_id = InstBlockId::None;
|
|
// The implicit `Self` parameter. This is a SymbolicBinding instruction.
|
|
InstId self_param_id = InstId::None;
|
|
|
|
// The following members are set at the `}` of the interface definition.
|
|
|
|
RequireImplsBlockId require_impls_block_id = RequireImplsBlockId::None;
|
|
InstBlockId associated_entities_id = InstBlockId::None;
|
|
};
|
|
|
|
// An interface. See EntityWithParamsBase regarding the inheritance here.
|
|
struct Interface : public EntityWithParamsBase,
|
|
public InterfaceFields,
|
|
public Printable<Interface> {
|
|
auto Print(llvm::raw_ostream& out) const -> void {
|
|
out << "{";
|
|
PrintBaseFields(out);
|
|
out << ", require_impls_block_id: " << require_impls_block_id;
|
|
out << "}";
|
|
}
|
|
|
|
// This is false until we reach the `}` of the interface definition.
|
|
auto is_complete() const -> bool {
|
|
return associated_entities_id.has_value();
|
|
}
|
|
|
|
// Determines whether we're currently defining the interface. This is true
|
|
// between the braces of the interface.
|
|
auto is_being_defined() const -> bool {
|
|
return has_definition_started() && !is_complete();
|
|
}
|
|
};
|
|
|
|
using InterfaceStore = ValueStore<InterfaceId, Interface, Tag<CheckIRId>>;
|
|
|
|
} // namespace Carbon::SemIR
|
|
|
|
#endif // CARBON_TOOLCHAIN_SEM_IR_INTERFACE_H_
|