Files
carbon-lang/toolchain/parse/handle_paren_expr.cpp
T
Geoff Romer 8c113c1241 Rename Parse::State to Parse::StateKind (#5249)
Also renames variables of that type to match. A follow-up PR will rename
`Parse::StateStackEntry` to `Parse::State`. This is more consistent with
the naming of similar enums elsewhere in the toolchain, and with the
prevailing practice of using `state` rather than e.g. `entry` as the
name of a `StateStackEntry`.

See also discussion
[here](https://discord.com/channels/655572317891461132/963846118964350976/1326280585592700990)
2025-04-05 04:25:00 +00:00

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3.9 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
#include "toolchain/parse/context.h"
#include "toolchain/parse/handle.h"
namespace Carbon::Parse {
auto HandleOnlyParenExpr(Context& context) -> void {
auto state = context.PopState();
// Advance past the open paren.
auto open_paren = context.ConsumeChecked(Lex::TokenKind::OpenParen);
context.AddLeafNode(NodeKind::ParenExprStart, open_paren);
state.token = open_paren;
context.PushState(state, StateKind::OnlyParenExprFinish);
context.PushState(StateKind::Expr);
}
static auto FinishParenExpr(Context& context,
const Context::StateStackEntry& state) -> void {
context.AddNode(NodeKind::ParenExpr, context.Consume(), state.has_error);
}
auto HandleOnlyParenExprFinish(Context& context) -> void {
auto state = context.PopState();
if (!context.PositionIs(Lex::TokenKind::CloseParen)) {
if (!state.has_error) {
CARBON_DIAGNOSTIC(UnexpectedTokenInCompoundMemberAccess, Error,
"expected `)`");
context.emitter().Emit(*context.position(),
UnexpectedTokenInCompoundMemberAccess);
state.has_error = true;
}
// Recover from the invalid token.
context.SkipTo(context.tokens().GetMatchedClosingToken(state.token));
}
FinishParenExpr(context, state);
}
auto HandleParenExpr(Context& context) -> void {
auto state = context.PopState();
// Advance past the open paren. The placeholder will be replaced at the end
// based on whether we determine this is a tuple or parenthesized expression.
context.AddLeafNode(NodeKind::Placeholder,
context.ConsumeChecked(Lex::TokenKind::OpenParen));
if (context.PositionIs(Lex::TokenKind::CloseParen)) {
context.PushState(state, StateKind::TupleLiteralFinish);
} else {
context.PushState(state, StateKind::ParenExprFinish);
context.PushState(StateKind::ExprAfterOpenParenFinish);
context.PushState(StateKind::Expr);
}
}
auto HandleExprAfterOpenParenFinish(Context& context) -> void {
auto state = context.PopState();
auto list_token_kind = context.ConsumeListToken(
NodeKind::TupleLiteralComma, Lex::TokenKind::CloseParen, state.has_error);
if (list_token_kind == Context::ListTokenKind::Close) {
return;
}
// We found a comma, so switch parent state to tuple handling.
auto finish_state = context.PopState();
CARBON_CHECK(finish_state.kind == StateKind::ParenExprFinish,
"Unexpected parent state, found: {0}", finish_state.kind);
context.PushState(finish_state, StateKind::TupleLiteralFinish);
// If the comma is not immediately followed by a close paren, push handlers
// for the next tuple element.
if (list_token_kind != Context::ListTokenKind::CommaClose) {
context.PushState(state, StateKind::TupleLiteralElementFinish);
context.PushState(StateKind::Expr);
}
}
auto HandleTupleLiteralElementFinish(Context& context) -> void {
auto state = context.PopState();
if (context.ConsumeListToken(NodeKind::TupleLiteralComma,
Lex::TokenKind::CloseParen, state.has_error) ==
Context::ListTokenKind::Comma) {
context.PushState(state);
context.PushState(StateKind::Expr);
}
}
auto HandleParenExprFinish(Context& context) -> void {
auto state = context.PopState();
context.ReplacePlaceholderNode(state.subtree_start, NodeKind::ParenExprStart,
state.token);
FinishParenExpr(context, state);
}
auto HandleTupleLiteralFinish(Context& context) -> void {
auto state = context.PopState();
context.ReplacePlaceholderNode(state.subtree_start,
NodeKind::TupleLiteralStart, state.token);
context.AddNode(NodeKind::TupleLiteral, context.Consume(), state.has_error);
}
} // namespace Carbon::Parse