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121 lines
3.9 KiB
C++
121 lines
3.9 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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// Handles VarAs(Decl|Returned).
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static auto HandleVar(Context& context, State finish_state,
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Lex::TokenIndex returned_token = Lex::TokenIndex::Invalid)
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-> void {
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auto state = context.PopState();
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// The finished variable declaration will start at the `var` or `returned`.
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context.PushState(state, finish_state);
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// TODO: is there a cleaner way to give VarAfterPattern access to the `var`
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// token?
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state.token = *(context.position() - 1);
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context.PushState(state, State::VarAfterPattern);
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if (returned_token.is_valid()) {
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context.AddLeafNode(NodeKind::ReturnedModifier, returned_token);
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}
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context.PushState(State::Pattern);
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}
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auto HandleVarAsDecl(Context& context) -> void {
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HandleVar(context, State::VarFinishAsDecl);
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}
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auto HandleVarAsReturned(Context& context) -> void {
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auto returned_token = context.Consume();
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if (!context.PositionIs(Lex::TokenKind::Var)) {
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CARBON_DIAGNOSTIC(ExpectedVarAfterReturned, Error,
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"expected `var` after `returned`");
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context.emitter().Emit(*context.position(), ExpectedVarAfterReturned);
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context.AddLeafNode(NodeKind::EmptyDecl,
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context.SkipPastLikelyEnd(returned_token),
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/*has_error=*/true);
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context.PopAndDiscardState();
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return;
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}
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context.AddLeafNode(NodeKind::VariableIntroducer, context.Consume());
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HandleVar(context, State::VarFinishAsDecl, returned_token);
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}
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auto HandleVarAsFor(Context& context) -> void {
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auto state = context.PopState();
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// The finished variable declaration will start at the `var`.
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context.PushState(state, State::VarFinishAsFor);
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context.PushState(State::Pattern);
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}
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auto HandleVarAfterPattern(Context& context) -> void {
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auto state = context.PopState();
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if (state.has_error) {
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if (auto after_pattern =
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context.FindNextOf({Lex::TokenKind::Equal, Lex::TokenKind::Semi})) {
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context.SkipTo(*after_pattern);
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}
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}
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context.AddNode(NodeKind::VariablePattern, state.token, state.has_error);
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if (context.PositionIs(Lex::TokenKind::Equal)) {
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context.AddLeafNode(NodeKind::VariableInitializer,
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context.ConsumeChecked(Lex::TokenKind::Equal));
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context.PushState(State::Expr);
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}
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}
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auto HandleVarFinishAsDecl(Context& context) -> void {
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auto state = context.PopState();
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auto end_token = state.token;
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if (context.PositionIs(Lex::TokenKind::Semi)) {
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end_token = context.Consume();
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} else {
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// TODO: Disambiguate between statement and member declaration.
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context.DiagnoseExpectedDeclSemi(Lex::TokenKind::Var);
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state.has_error = true;
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end_token = context.SkipPastLikelyEnd(state.token);
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}
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context.AddNode(NodeKind::VariableDecl, end_token, state.has_error);
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}
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auto HandleVarFinishAsFor(Context& context) -> void {
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auto state = context.PopState();
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context.AddNode(NodeKind::VariablePattern, state.token, state.has_error);
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auto end_token = state.token;
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if (context.PositionIs(Lex::TokenKind::In)) {
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end_token = context.Consume();
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} else if (context.PositionIs(Lex::TokenKind::Colon)) {
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CARBON_DIAGNOSTIC(ExpectedInNotColon, Error,
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"`:` should be replaced by `in`");
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context.emitter().Emit(*context.position(), ExpectedInNotColon);
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state.has_error = true;
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end_token = context.Consume();
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} else {
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CARBON_DIAGNOSTIC(ExpectedIn, Error,
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"expected `in` after loop `var` declaration");
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context.emitter().Emit(*context.position(), ExpectedIn);
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state.has_error = true;
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}
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context.AddNode(NodeKind::ForIn, end_token, state.has_error);
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}
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} // namespace Carbon::Parse
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