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81 lines
2.7 KiB
C++
81 lines
2.7 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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namespace Carbon::Parse {
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auto HandleParenExpr(Context& context) -> void {
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auto state = context.PopState();
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// Advance past the open paren.
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context.AddLeafNode(NodeKind::ParenExprOrTupleLiteralStart,
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context.ConsumeChecked(Lex::TokenKind::OpenParen));
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if (context.PositionIs(Lex::TokenKind::CloseParen)) {
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state.state = State::ParenExprFinishAsTuple;
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context.PushState(state);
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} else {
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state.state = State::ParenExprFinishAsNormal;
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context.PushState(state);
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context.PushState(State::ParenExprParameterFinishAsUnknown);
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context.PushState(State::Expr);
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}
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}
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// Handles ParenExprParameterFinishAs(Unknown|Tuple).
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static auto HandleParenExprParameterFinish(Context& context, bool as_tuple)
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-> void {
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auto state = context.PopState();
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auto list_token_kind = context.ConsumeListToken(
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NodeKind::TupleLiteralComma, Lex::TokenKind::CloseParen, state.has_error);
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if (list_token_kind == Context::ListTokenKind::Close) {
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return;
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}
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// If this is the first item and a comma was found, switch to tuple handling.
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// Note this could be `(expr,)` so we may not reuse the current state, but
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// it's still necessary to switch the parent.
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if (!as_tuple) {
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state.state = State::ParenExprParameterFinishAsTuple;
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auto finish_state = context.PopState();
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CARBON_CHECK(finish_state.state == State::ParenExprFinishAsNormal)
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<< "Unexpected parent state, found: " << finish_state.state;
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finish_state.state = State::ParenExprFinishAsTuple;
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context.PushState(finish_state);
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}
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// On a comma, push another expression handler.
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if (list_token_kind == Context::ListTokenKind::Comma) {
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context.PushState(state);
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context.PushState(State::Expr);
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}
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}
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auto HandleParenExprParameterFinishAsUnknown(Context& context) -> void {
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HandleParenExprParameterFinish(context, /*as_tuple=*/false);
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}
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auto HandleParenExprParameterFinishAsTuple(Context& context) -> void {
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HandleParenExprParameterFinish(context, /*as_tuple=*/true);
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}
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auto HandleParenExprFinishAsNormal(Context& context) -> void {
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auto state = context.PopState();
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context.AddNode(NodeKind::ParenExpr, context.Consume(), state.subtree_start,
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state.has_error);
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}
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auto HandleParenExprFinishAsTuple(Context& context) -> void {
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auto state = context.PopState();
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context.AddNode(NodeKind::TupleLiteral, context.Consume(),
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state.subtree_start, state.has_error);
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}
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} // namespace Carbon::Parse
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