compiler_action.h

#ifndef __TAN_COMMON_COMPILER_ACTION_H__
#define __TAN_COMMON_COMPILER_ACTION_H__
 
#include "common/ast_visitor.h"
 
namespace tanlang {
 
template <class T, class U>
concept SameHelper = std::is_same_v<T, U>;
 
/**
 * \brief Some compilers don't have std::same_as
 */
template <class T, class U>
concept same_as = SameHelper<T, U> && SameHelper<U, T>;
 
template <typename C, typename Input, typename Output>
concept HasImpl = requires(C c, Input input) {
  { c.run_impl(input) } -> same_as<Output>;
};
 
template <typename Derived, typename Input, typename Output> class CompilerAction : public ASTVisitor<Derived> {
public:
  using CompilerActionType = CompilerAction<Derived, Input, Output>;
 
  virtual ~CompilerAction() = default;
 
  Output run(Input input) {
    static_assert(HasImpl<Derived, Input, Output>);
 
    init(input);
    return ((Derived *)this)->run_impl(input);
  }
 
protected:
  virtual void init(Input){};
};
 
} // namespace tanlang
 
#endif // __TAN_COMMON_COMPILER_ACTION_H__