xo-reader2/xo-reader/include/xo/reader/lambda_xs.hpp

121 lines
3.8 KiB
C++

/** @file lambda_xs.hpp
*
* Author: Roland Conybeare
**/
#pragma once
#include "exprstate.hpp"
#include "xo/expression/LocalEnv.hpp"
//#include <cstdint>
namespace xo {
namespace scm {
/**
* @text
*
* lambda ( name(1) : type(1), ..., ) : type body-expr ;
* ^ ^ ^ ^ ^ ^
* | | | | lm_4 lm_5
* | | | lm_3
* lm_0 lm_1 lm_2
*
* lm_0 --on_lambda_token()--> lm_1
* lm_1 --on_formal_arglist()--> lm_2
* lm_2 --on_expr()--> lm_3
* lm_5 --on_semicolon_token()--> (done)
*
* @endtext
**/
enum class lambdastatetype {
invalid = -1,
lm_0,
lm_1,
lm_2,
lm_3,
lm_4,
lm_5,
n_lambdastatetype
};
extern const char *
lambdastatetype_descr(lambdastatetype x);
inline std::ostream &
operator<< (std::ostream & os, lambdastatetype x) {
os << lambdastatetype_descr(x);
return os;
}
/** @class lambda_xs
* @brief parsing state-machine for a lambda-expression
*
**/
class lambda_xs : public exprstate {
public:
using Environment = xo::scm::Environment;
using LocalEnv = xo::scm::LocalEnv;
public:
lambda_xs();
static void start(parserstatemachine * p_psm);
virtual const char * get_expect_str() const override;
virtual void on_lambda_token(const token_type & tk,
parserstatemachine * p_psm) override;
virtual void on_typedescr(TypeDescr td,
parserstatemachine * p_psm) override;
virtual void on_formal_arglist(const std::vector<rp<Variable>> & argl,
parserstatemachine * p_psm) override;
virtual void on_expr(bp<Expression> expr,
parserstatemachine * p_psm) override;
virtual void on_expr_with_semicolon(bp<Expression> expr,
parserstatemachine * p_psm) override;
virtual void on_leftbrace_token(const token_type & tk,
parserstatemachine * p_psm) override;
virtual void on_colon_token(const token_type & tk,
parserstatemachine * p_psm) override;
virtual void on_semicolon_token(const token_type & tk,
parserstatemachine * p_psm) override;
virtual void print(std::ostream & os) const override;
virtual bool pretty_print(const print::ppindentinfo & ppii) const override;
private:
static std::unique_ptr<lambda_xs> make();
private:
/** parsing state-machine state **/
lambdastatetype lmxs_type_ = lambdastatetype::lm_0;
/** lambda environment (for formal parameters) **/
rp<LocalEnv> local_env_;
/** explicit return type (if supplied) **/
TypeDescr explicit_return_td_ = nullptr;
/** lambda signature (when known) **/
TypeDescr lambda_td_ = nullptr;
/** body expression **/
rp<Expression> body_;
/** parent environment **/
rp<Environment> parent_env_;
};
} /*namespace scm*/
namespace print {
#ifndef ppdetail_atomic
PPDETAIL_ATOMIC(xo::scm::lambdastatetype);
#endif
}
} /*namespace xo*/
/** end lambda_xs.hpp **/