xo-expression2/xo-expression/include/xo/expression/GeneralizedExpression.hpp

72 lines
2.7 KiB
C++

/** @file GeneralizedExpression.hpp
*
* Author: Roland Conybeare
**/
#pragma once
#include "xo/refcnt/Refcounted.hpp"
#include "xo/expression/typeinf/type_ref.hpp"
//#include "xo/reflect/TypeDescr.hpp"
#include "exprtype.hpp"
namespace xo {
namespace ast {
/** @class GeneralizedExpression
* @brief abstract syntax tree (non-executable) for schematica
*
* 'Generalized' because it includes both kernel and macro expressions.
* Every macro expression automatically translates to an equivalent kernel expression.
* Kernel expressions are directly executable.
**/
class GeneralizedExpression : public ref::Refcount {
public:
using type_ref = xo::scm::type_ref;
using prefix_type = xo::scm::prefix_type;
using TypeDescr = xo::reflect::TypeDescr;
using ppstate = xo::print::ppstate;
using ppindentinfo = xo::print::ppindentinfo;
public:
/** if @p valuetype is null, generate unique type variable
* using prefix derived from @p extype.
**/
GeneralizedExpression(exprtype extype, TypeDescr valuetype);
/** if @p valuetype is null, generate unique type variable
* name, beginning with @p prefix
**/
GeneralizedExpression(exprtype extype, prefix_type prefix, TypeDescr valuetype);
exprtype extype() const { return extype_; }
const type_ref & valuetype_ref() const { return valuetype_ref_; }
TypeDescr valuetype() const { return valuetype_ref_.td(); }
/** write human-readable representation to stream @p os **/
virtual void display(std::ostream & os) const = 0;
/** human-readable string representation **/
virtual std::string display_string() const;
/** pretty printing support. See [xo-indentlog/xo/indentlog/pretty.hpp] **/
virtual std::uint32_t pretty_print(const ppindentinfo & ppii) const = 0;
/** useful when scaffolding expressions in a parser **/
void assign_valuetype(TypeDescr x) { valuetype_ref_.resolve_to(x); }
private:
/** expression type (constant | apply | ..) for this expression **/
exprtype extype_ = exprtype::invalid;
/** type information (when available) for values produced by this
* expression.
**/
type_ref valuetype_ref_;
};
inline std::ostream &
operator<<(std::ostream & os, const GeneralizedExpression & x) {
x.display(os);
return os;
}
} /*namespace ast*/
} /*namespace xo*/
/* end GeneralizedExpression.hpp */