source: src/ResolvExpr/Alternative.h @ 6d6e829

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Alternative.h --
//
// Author           : Richard C. Bilson
// Created On       : Sat May 16 23:45:43 2015
// Last Modified By : Aaron B. Moss
// Last Modified On : Thu Oct 11 10:55:00 2018
// Update Count     : 4
//

#pragma once

#include <iosfwd>             // for ostream
#include <vector>             // for vector

#include "Cost.h"             // for Cost
#include "TypeEnvironment.h"  // for TypeEnvironment, AssertionSetValue

class Expression;

namespace ResolvExpr {
        /// One assertion to resolve
        struct AssertionItem {
                DeclarationWithType* decl;
                AssertionSetValue info;
                
                AssertionItem() = default;
                AssertionItem( DeclarationWithType* decl, const AssertionSetValue& info ) 
                : decl(decl), info(info) {}
                AssertionItem( const AssertionSet::value_type& e ) : decl(e.first), info(e.second) {}
                operator AssertionSet::value_type () const { return { decl, info }; }
        };
        /// A list of unresolved assertions
        using AssertionList = std::vector<AssertionItem>;

        /// One option for resolution of an expression
        struct Alternative {
                Alternative();
                Alternative( Expression *expr, const TypeEnvironment &env );
                Alternative( const Alternative &o, Expression *expr, const Cost &cost );
                Alternative( Expression *expr, const TypeEnvironment &env, const OpenVarSet& openVars, 
                        const AssertionList& need, const Cost &cost );
                Alternative( Expression *expr, const TypeEnvironment &env, const OpenVarSet& openVars, 
                        const AssertionList& need, const Cost &cost, const Cost &cvtCost );
                Alternative( const Alternative &other );
                Alternative &operator=( const Alternative &other );
                Alternative( Alternative && other );
                Alternative &operator=( Alternative && other );
                ~Alternative();

                void print( std::ostream &os, Indenter indent = {} ) const;

                /// Returns the stored expression, but released from management of this Alternative
                Expression* release_expr() {
                        Expression* tmp = expr;
                        expr = nullptr;
                        return tmp;
                }

                /// Sorts by cost
                bool operator< ( const Alternative& o ) const { return cost < o.cost; }

                Cost cost;            ///< Cost of the whole expression
                Cost cvtCost;         ///< Cost of conversions to the satisfying expression
                Expression *expr;     ///< Satisfying expression
                TypeEnvironment env;  ///< Containing type environment
                OpenVarSet openVars;  ///< Open variables for environment
                AssertionList need;   ///< Assertions which need to be resolved
        };

        typedef std::vector< Alternative > AltList;

        /// Moves all elements from src to the end of dst
        void splice( AltList& dst, AltList& src );

        /// Moves all elements from src to the beginning of dst
        void spliceBegin( AltList& dst, AltList& src );

        static inline std::ostream & operator<<(std::ostream & os, const ResolvExpr::Alternative & alt) {
                alt.print( os );
                return os;
        }
} // namespace ResolvExpr

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //