Files
carbon-lang/executable_semantics/ast/statement.h
T
Jeremy G. Siek 34f1a03f7b change all expression and statement pointers to be const (#449)
* change all expression and statement pointers to be const

* const in paren tests
2021-04-19 21:47:19 -04:00

128 lines
3.4 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
#ifndef EXECUTABLE_SEMANTICS_AST_STATEMENT_H_
#define EXECUTABLE_SEMANTICS_AST_STATEMENT_H_
#include <list>
#include "executable_semantics/ast/expression.h"
namespace Carbon {
enum class StatementKind {
ExpressionStatement,
Assign,
VariableDefinition,
If,
Return,
Sequence,
Block,
While,
Break,
Continue,
Match,
Continuation, // Create a first-class continuation.
Run, // Run a continuation to the next await or until it finishes..
Await, // Pause execution of the continuation.
};
struct Statement {
int line_num;
StatementKind tag;
union {
const Expression* exp;
struct {
const Expression* lhs;
const Expression* rhs;
} assign;
struct {
const Expression* pat;
const Expression* init;
} variable_definition;
struct {
const Expression* cond;
const Statement* then_stmt;
const Statement* else_stmt;
} if_stmt;
const Expression* return_stmt;
struct {
const Statement* stmt;
const Statement* next;
} sequence;
struct {
const Statement* stmt;
} block;
struct {
const Expression* cond;
const Statement* body;
} while_stmt;
struct {
const Expression* exp;
std::list<std::pair<const Expression*, const Statement*>>* clauses;
} match_stmt;
struct {
std::string* continuation_variable;
const Statement* body;
} continuation;
struct {
const Expression* argument;
} run;
} u;
};
auto MakeExpStmt(int line_num, const Expression* exp) -> const Statement*;
auto MakeAssign(int line_num, const Expression* lhs, const Expression* rhs)
-> const Statement*;
auto MakeVarDef(int line_num, const Expression* pat, const Expression* init)
-> const Statement*;
auto MakeIf(int line_num, const Expression* cond, const Statement* then_stmt,
const Statement* else_stmt) -> const Statement*;
auto MakeReturn(int line_num, const Expression* e) -> const Statement*;
auto MakeSeq(int line_num, const Statement* s1, const Statement* s2)
-> const Statement*;
auto MakeBlock(int line_num, const Statement* s) -> const Statement*;
auto MakeWhile(int line_num, const Expression* cond, const Statement* body)
-> const Statement*;
auto MakeBreak(int line_num) -> const Statement*;
auto MakeContinue(int line_num) -> const Statement*;
auto MakeMatch(
int line_num, const Expression* exp,
std::list<std::pair<const Expression*, const Statement*>>* clauses)
-> const Statement*;
// Returns an AST node for a continuation statement give its line number and
// contituent parts.
//
// __continuation <continuation_variable> {
// <body>
// }
auto MakeContinuationStatement(int line_num, std::string continuation_variable,
const Statement* body) -> const Statement*;
// Returns an AST node for a run statement give its line number and argument.
//
// __run <argument>;
auto MakeRun(int line_num, const Expression* argument) -> const Statement*;
// Returns an AST node for an await statement give its line number.
//
// __await;
auto MakeAwait(int line_num) -> const Statement*;
void PrintStatement(const Statement*, int);
} // namespace Carbon
#endif // EXECUTABLE_SEMANTICS_AST_STATEMENT_H_