Files
carbon-lang/toolchain/parse/handle_requirement.cpp
T
d6b2fb1736 Add parse support for multiple requirements after where separated by and (#4298)
Follow on to #4275 that added `where` parse support.

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Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2024-09-11 21:36:55 +00:00

91 lines
2.8 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/lex/token_kind.h"
#include "toolchain/parse/context.h"
#include "toolchain/parse/handle.h"
namespace Carbon::Parse {
auto HandleRequirementBegin(Context& context) -> void {
context.PopAndDiscardState();
// TODO: Peek ahead for `.designator = ...`, and give it special handling.
context.PushState(State::RequirementOperator);
context.PushStateForExpr(PrecedenceGroup::ForRequirements());
}
auto HandleRequirementOperator(Context& context) -> void {
auto state = context.PopState();
switch (context.PositionKind()) {
case Lex::TokenKind::Impls: {
break;
}
case Lex::TokenKind::Equal: {
break;
}
case Lex::TokenKind::EqualEqual: {
break;
}
default: {
if (!state.has_error) {
CARBON_DIAGNOSTIC(
ExpectedRequirementOperator, Error,
"Requirement should use `impls`, `=`, or `==` operator.");
context.emitter().Emit(*context.position(),
ExpectedRequirementOperator);
}
context.ReturnErrorOnState();
return;
}
}
state.token = context.Consume();
context.PushState(state, State::RequirementOperatorFinish);
context.PushStateForExpr(PrecedenceGroup::ForRequirements());
}
auto HandleRequirementOperatorFinish(Context& context) -> void {
auto state = context.PopState();
switch (auto token_kind = context.tokens().GetKind(state.token)) {
case Lex::TokenKind::Impls: {
context.AddNode(NodeKind::RequirementImpls, state.token, state.has_error);
break;
}
case Lex::TokenKind::Equal: {
context.AddNode(NodeKind::RequirementEqual, state.token, state.has_error);
break;
}
case Lex::TokenKind::EqualEqual: {
context.AddNode(NodeKind::RequirementEqualEqual, state.token,
state.has_error);
break;
}
default:
// RequirementOperatorFinish state is only pushed in
// HandleRequirementOperator on one of the three requirement operator
// tokens.
CARBON_FATAL() << "Unexpected token kind for requirement operator: "
<< token_kind;
return;
}
if (state.has_error) {
context.ReturnErrorOnState();
}
if (auto token = context.ConsumeIf(Lex::TokenKind::And)) {
context.AddNode(NodeKind::RequirementAnd, *token, /*has_error=*/false);
context.PushState(State::RequirementBegin);
}
}
auto HandleWhereFinish(Context& context) -> void {
auto state = context.PopState();
if (state.has_error) {
context.ReturnErrorOnState();
}
context.AddNode(NodeKind::WhereExpr, state.token, state.has_error);
}
} // namespace Carbon::Parse