mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 20:30:14 +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.
30 lines
972 B
C++
30 lines
972 B
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#include "toolchain/check/generic_region_stack.h"
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#include "common/vlog.h"
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namespace Carbon::Check {
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auto GenericRegionStack::Push(PendingGeneric generic) -> void {
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CARBON_VLOG("GenericRegion Push: {0} {1}\n", generic.generic_id,
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generic.region);
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pending_generic_ids_.push_back(generic);
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pending_eval_block_stack_.PushArray();
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dependent_inst_stack_.PushArray();
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constants_in_generic_stack_.emplace_back();
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}
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auto GenericRegionStack::Pop() -> void {
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auto pending = pending_generic_ids_.pop_back_val();
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CARBON_VLOG("GenericRegion Pop: {0} {1}\n", pending.generic_id,
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pending.region);
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pending_eval_block_stack_.PopArray();
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dependent_inst_stack_.PopArray();
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constants_in_generic_stack_.pop_back();
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}
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} // namespace Carbon::Check
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