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oli-ej
a683fb574b
Implements parsing of struct patterns as per https://github.com/carbon-language/carbon-lang/issues/6680. This handles the full and short syntax given in the [design doc](https://github.com/carbon-language/carbon-lang/blob/trunk/docs/design/pattern_matching.md#struct-patterns), but the handling of the shorthand syntax may need to change as I move on to implementing Check support (currently the shorthand is represented as one of `LetBindingPattern`, `VarBindingPattern`, or `VariablePattern`). This implementation assumes that the answer to https://github.com/carbon-language/carbon-lang/issues/7404 is that trailing commas are allowed in the struct pattern, except for the case where an `_` is present, in which case the next token must be the closing brace `}`.
39 lines
1.3 KiB
C++
39 lines
1.3 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/parse/context.h"
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#include "toolchain/parse/handle.h"
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namespace Carbon::Parse {
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auto HandleUnusedPattern(Context& context) -> void {
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auto state = context.PopState();
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if (state.in_unused_pattern) {
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CARBON_DIAGNOSTIC(NestedUnused, Error,
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"`unused` nested within another `unused`");
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context.emitter().Emit(*context.position(), NestedUnused);
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state.has_error = true;
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}
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context.PushState(StateKind::FinishUnusedPattern);
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context.ConsumeChecked(Lex::TokenKind::Unused);
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context.PushStateForPattern(StateKind::Pattern, state.in_var_pattern,
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/*in_unused_pattern=*/true,
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state.in_field_shorthand_pattern,
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state.binding_context, state.ambient_precedence);
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}
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auto HandleFinishUnusedPattern(Context& context) -> void {
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auto state = context.PopState();
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context.AddNode(NodeKind::UnusedPattern, state.token, state.has_error);
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// Propagate errors to the parent state so that they can take different
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// actions on invalid patterns.
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if (state.has_error) {
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context.ReturnErrorOnState();
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}
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}
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} // namespace Carbon::Parse
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