Files
carbon-lang/explorer/ast/statement.cpp
T
SlaterLatiao 9106e9239e Initial implementation of returned var. (#1348)
This PR implements the `returned var` for the explorer.
- Enabled `returned var` and `return var` syntax in lexer and parser.
- Split `Return` statement into `ReturnVar` and `ReturnExpression` to distinguish the two types of returns.
- Added logic in name resolution, type checking and interpretation to process `returned var` definition and `ReturnVar` statement.
2022-07-06 13:35:41 -07:00

130 lines
3.5 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 "explorer/ast/statement.h"
#include "common/check.h"
#include "explorer/common/arena.h"
#include "llvm/Support/Casting.h"
namespace Carbon {
using llvm::cast;
Statement::~Statement() = default;
void Statement::PrintDepth(int depth, llvm::raw_ostream& out) const {
if (depth == 0) {
out << " ... ";
return;
}
switch (kind()) {
case StatementKind::Match: {
const auto& match = cast<Match>(*this);
out << "match (" << match.expression() << ") {";
if (depth < 0 || depth > 1) {
out << "\n";
for (auto& clause : match.clauses()) {
out << "case " << clause.pattern() << " =>\n";
clause.statement().PrintDepth(depth - 1, out);
out << "\n";
}
} else {
out << "...";
}
out << "}";
break;
}
case StatementKind::While: {
const auto& while_stmt = cast<While>(*this);
out << "while (" << while_stmt.condition() << ")\n";
while_stmt.body().PrintDepth(depth - 1, out);
break;
}
case StatementKind::Break:
out << "break;";
break;
case StatementKind::Continue:
out << "continue;";
break;
case StatementKind::VariableDefinition: {
const auto& var = cast<VariableDefinition>(*this);
if (var.is_returned()) {
out << "returned ";
}
out << "var " << var.pattern() << " = " << var.init() << ";";
break;
}
case StatementKind::ExpressionStatement:
out << cast<ExpressionStatement>(*this).expression() << ";";
break;
case StatementKind::Assign: {
const auto& assign = cast<Assign>(*this);
out << assign.lhs() << " = " << assign.rhs() << ";";
break;
}
case StatementKind::If: {
const auto& if_stmt = cast<If>(*this);
out << "if (" << if_stmt.condition() << ")\n";
if_stmt.then_block().PrintDepth(depth - 1, out);
if (if_stmt.else_block()) {
out << "\nelse\n";
(*if_stmt.else_block())->PrintDepth(depth - 1, out);
}
break;
}
case StatementKind::ReturnVar: {
out << "return var;";
break;
}
case StatementKind::ReturnExpression: {
const auto& ret = cast<ReturnExpression>(*this);
if (ret.is_omitted_expression()) {
out << "return;";
} else {
out << "return " << ret.expression() << ";";
}
break;
}
case StatementKind::Block: {
const auto& block = cast<Block>(*this);
out << "{";
if (depth < 0 || depth > 1) {
out << "\n";
}
for (const auto* statement : block.statements()) {
statement->PrintDepth(depth, out);
if (depth < 0 || depth > 1) {
out << "\n";
}
}
out << "}";
if (depth < 0 || depth > 1) {
out << "\n";
}
break;
}
case StatementKind::Continuation: {
const auto& cont = cast<Continuation>(*this);
out << "continuation " << cont.name() << " ";
if (depth < 0 || depth > 1) {
out << "\n";
}
cont.body().PrintDepth(depth - 1, out);
if (depth < 0 || depth > 1) {
out << "\n";
}
break;
}
case StatementKind::Run:
out << "run " << cast<Run>(*this).argument() << ";";
break;
case StatementKind::Await:
out << "await;";
break;
}
}
} // namespace Carbon