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Özgür
d11ee4b2b1
This implements parsing of the [`observe`](https://docs.carbon-lang.dev/docs/design/generics/details.html#observing-a-type-implements-an-interface) declarations. - Added states and node kinds. - Added node categories. - Added a diagnostic for invalid keywords/operators. - Implemented parser state handlers. - Added structs to `typed_nodes.h`. - Added parser tests.
73 lines
2.5 KiB
C++
73 lines
2.5 KiB
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/lex/token_kind.h"
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#include "toolchain/parse/context.h"
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#include "toolchain/parse/handle.h"
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#include "toolchain/parse/node_kind.h"
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#include "toolchain/parse/precedence.h"
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#include "toolchain/parse/state.h"
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#include "toolchain/parse/typed_nodes.h"
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namespace Carbon::Parse {
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auto HandleObserveAfterIntroducer(Context& context) -> void {
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auto state = context.PopState();
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context.PushState(state, StateKind::ObserveOperator);
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context.PushStateForExpr(PrecedenceGroup::ForRequirements());
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}
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auto HandleObserveOperator(Context& context) -> void {
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auto state = context.PopState();
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switch (context.PositionKind()) {
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case Lex::TokenKind::EqualEqual: {
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state.token = context.Consume();
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context.PushState(state, StateKind::ObserveFinishOperator);
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context.PushStateForExpr(PrecedenceGroup::ForRequirements());
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return;
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}
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case Lex::TokenKind::Impls: {
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state.token = context.Consume();
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context.PushState(state, StateKind::ObserveFinishOperator);
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context.PushState(StateKind::Expr);
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return;
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}
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default: {
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if (!state.has_error) {
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CARBON_DIAGNOSTIC(ExpectedObserveOperator, Error,
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"observe should use `==` or `impls` operator");
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context.emitter().Emit(*context.position(), ExpectedObserveOperator);
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}
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context.RecoverFromDeclError(state, NodeKind::ObserveDecl,
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/*skip_past_likely_end=*/true);
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return;
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}
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}
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}
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auto HandleObserveFinishOperator(Context& context) -> void {
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auto state = context.PopState();
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auto token_kind = context.tokens().GetKind(state.token);
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if (token_kind == Lex::TokenKind::EqualEqual) {
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context.AddNode(NodeKind::ObserveEqualEqual, state.token, state.has_error);
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} else {
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context.AddNode(NodeKind::ObserveImpls, state.token, state.has_error);
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}
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if (context.PositionIs(Lex::TokenKind::Semi)) {
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context.PushState(state, StateKind::ObserveDecl);
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} else {
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context.PushState(state, StateKind::ObserveOperator);
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}
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}
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auto HandleObserveDecl(Context& context) -> void {
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auto state = context.PopState();
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context.AddNodeExpectingDeclSemi(state, NodeKind::ObserveDecl,
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Lex::TokenKind::Observe,
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/*is_def_allowed=*/false);
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}
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} // namespace Carbon::Parse
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