95 lines
2.8 KiB
C++
95 lines
2.8 KiB
C++
/** @file lambda_xs.hpp
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*
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* Author: Roland Conybeare
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**/
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#pragma once
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#include "exprstate.hpp"
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#include "xo/expression/LocalEnv.hpp"
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//#include <cstdint>
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namespace xo {
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namespace scm {
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/**
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* lambda ( name(1) : type(1), ..., ) body-expr ;
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* ^ ^ ^ ^
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* | | | |
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* lm_0 lm_1 lm_2 lm_3
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*
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* lm_0 --on_lambda_token()--> lm_1
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* lm_1 --on_formal_arglist()--> lm_2
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* lm_2 --on_expr()--> lm_3
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* lm_3 --on_semicolon_token()--> (done)
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**/
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enum class lambdastatetype {
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invalid = -1,
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lm_0,
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lm_1,
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lm_2,
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lm_3,
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n_lambdastatetype
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};
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extern const char *
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lambdastatetype_descr(lambdastatetype x);
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inline std::ostream &
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operator<< (std::ostream & os, lambdastatetype x) {
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os << lambdastatetype_descr(x);
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return os;
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}
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/** @class lambda_xs
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* @brief parsing state-machine for a lambda-expression
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*
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**/
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class lambda_xs : public exprstate {
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public:
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using Environment = xo::ast::Environment;
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using LocalEnv = xo::ast::LocalEnv;
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public:
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lambda_xs();
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static void start(parserstatemachine * p_psm);
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virtual const char * get_expect_str() const override;
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virtual void on_lambda_token(const token_type & tk,
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parserstatemachine * p_psm) override;
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virtual void on_formal_arglist(const std::vector<rp<Variable>> & argl,
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parserstatemachine * p_psm) override;
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virtual void on_expr(bp<Expression> expr,
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parserstatemachine * p_psm) override;
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virtual void on_expr_with_semicolon(bp<Expression> expr,
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parserstatemachine * p_psm) override;
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virtual void on_semicolon_token(const token_type & tk,
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parserstatemachine * p_psm) override;
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virtual void print(std::ostream & os) const override;
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private:
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static std::unique_ptr<lambda_xs> make();
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private:
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/** parsing state-machine state **/
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lambdastatetype lmxs_type_ = lambdastatetype::lm_0;
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/** lambda environment (for formal parameters) **/
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rp<LocalEnv> local_env_;
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/** body expression **/
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rp<Expression> body_;
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/** parent environment **/
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rp<Environment> parent_env_;
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};
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} /*namespace scm*/
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} /*namespace xo*/
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/** end lambda_xs.hpp **/
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