carbon-lang/executable_semantics/interpreter/typecheck.h

// 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_INTERPRETER_TYPECHECK_H_
#define EXECUTABLE_SEMANTICS_INTERPRETER_TYPECHECK_H_

#include <set>

#include "common/ostream.h"
#include "executable_semantics/ast/expression.h"
#include "executable_semantics/ast/statement.h"
#include "executable_semantics/common/ptr.h"
#include "executable_semantics/interpreter/dictionary.h"
#include "executable_semantics/interpreter/interpreter.h"

namespace Carbon {

using TypeEnv = Dictionary<std::string, const Value*>;

struct TCExpression {
  TCExpression(Ptr<const Expression> e, const Value* t, TypeEnv types)
      : exp(e), type(t), types(types) {}

  Ptr<const Expression> exp;
  const Value* type;
  TypeEnv types;
};

struct TCPattern {
  Ptr<const Pattern> pattern;
  const Value* type;
  TypeEnv types;
};

struct TCStatement {
  TCStatement(Ptr<const Statement> s, TypeEnv types) : stmt(s), types(types) {}

  Ptr<const Statement> stmt;
  TypeEnv types;
};

struct TypeCheckContext {
  // Symbol table mapping names of runtime entities to their type.
  TypeEnv types;
  // Symbol table mapping names of compile time entities to their value.
  Env values;
};

auto TypeCheckExp(Ptr<const Expression> e, TypeEnv types, Env values)
    -> TCExpression;
auto TypeCheckPattern(Ptr<const Pattern> p, TypeEnv types, Env values,
                      const Value* expected) -> TCPattern;

auto TypeCheckStmt(Ptr<const Statement> s, TypeEnv types, Env values,
                   const Value*& ret_type, bool is_omitted_ret_type)
    -> TCStatement;

auto MakeTypeChecked(const Ptr<const Declaration> d, const TypeEnv& types,
                     const Env& values) -> Ptr<const Declaration>;
auto TopLevel(const std::list<Ptr<const Declaration>>& fs) -> TypeCheckContext;

}  // namespace Carbon

#endif  // EXECUTABLE_SEMANTICS_INTERPRETER_TYPECHECK_H_