xo-alloc/include/xo/reader/progress_xs.hpp

111 lines
4 KiB
C++

/** @file progress_xs.hpp
*
* Author: Roland Conybeare
**/
#pragma once
#include "exprstate.hpp"
#include <iostream>
//#include <cstdint>
namespace xo {
namespace scm {
/* represent an infix operator */
enum class optype {
invalid = -1,
op_add,
op_subtract,
op_multiply,
op_divide,
n_optype
};
extern const char *
optype_descr(optype x);
inline std::ostream &
operator<< (std::ostream & os, optype x) {
os << optype_descr(x);
return os;
}
/** @class progress_xs
* @brief state machine for parsing a schematica runtime-value-expression
**/
class progress_xs : public exprstate {
public:
progress_xs(rp<Expression> valex);
virtual ~progress_xs() = default;
static const progress_xs * from(const exprstate * x) { return dynamic_cast<const progress_xs *>(x); }
static std::unique_ptr<progress_xs> make(rp<Expression> valex);
bool admits_f64() const;
virtual void on_expr(ref::brw<Expression> expr,
exprstatestack * p_stack,
rp<Expression> * p_emit_expr) override;
virtual void on_symbol_token(const token_type & tk,
exprstatestack * p_stack,
rp<Expression> * p_emit_expr) override;
virtual void on_typedescr(TypeDescr td,
exprstatestack * /*p_stack*/,
rp<Expression> * /*p_emit_expr*/) override;
virtual void on_def_token(const token_type & tk,
exprstatestack * p_stack) override;
virtual void on_colon_token(const token_type & tk,
exprstatestack * p_stack) override;
virtual void on_semicolon_token(const token_type & tk,
exprstatestack * p_stack,
rp<Expression> * /*p_emit_expr*/) override;
virtual void on_singleassign_token(const token_type & tk,
exprstatestack * p_stack) override;
virtual void on_leftparen_token(const token_type & tk,
exprstatestack * p_stack,
rp<Expression> * /*p_emit_expr*/) override;
virtual void on_rightparen_token(const token_type & tk,
exprstatestack * p_stack,
rp<Expression> * /*p_emit_expr*/) override;
/* entry point for an infix operator token */
virtual void on_operator_token(const token_type & tk,
exprstatestack * p_stack,
rp<Expression> * p_emit_expr) override;
virtual void on_f64_token(const token_type & tk,
exprstatestack * p_stack,
rp<Expression> * /*p_emit_expr*/) override;
virtual void print(std::ostream & os) const override;
private:
/** assemble expression representing
* value of
* @code
* f(lhs_, rhs_)
* @endcode
*
* where f determined by @ref op_type_
**/
rp<Expression> assemble_expr();
private:
/** populate an expression here, may be followed by an operator **/
rp<Expression> lhs_;
/** infix operator, if supplied **/
optype op_type_ = optype::invalid;
/** populate an expression here, following infix operator */
rp<Expression> rhs_;
};
} /*namespace scm*/
} /*namespace xo*/
/** end progress_xs.hpp **/