source: src/ResolvExpr/CurrentObject.h @ 66ba544

//
// 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.
//
// CurrentObject.h --
//
// Author           : Rob Schluntz
// Created On       : Thu Jun  8 11:07:25 2017
// Last Modified By : Peter A. Buhr
// Last Modified On : Sat Jul 22 09:36:48 2017
// Update Count     : 3
//

#pragma once

#include <deque>
#include <list>   // for list
#include <memory> // for unique_ptr
#include <stack>  // for stack
#include <vector>

#include "AST/Node.hpp"  // for ptr
#include "Common/CodeLocation.h"

class Designation;
class Type;
struct InitAlternative;

namespace ResolvExpr {
        class MemberIterator;

        // TODO: memory management of MemberIterators
        class CurrentObject {
        public:
                CurrentObject();
                CurrentObject( Type * type );

                /// resolves unresolved designation
                Designation * findNext( Designation * designation );
                /// sets current position using resolved designation
                void setNext( Designation * designation );
                /// steps to next sub-object of current-object
                void increment();
                /// sets new current-object for the duration of this brace-enclosed initializer-list
                void enterListInit();
                /// restores previous current-object
                void exitListInit();
                /// produces a list of alternatives (Type *, Designation *) for the current sub-object's initializer
                std::list< InitAlternative > getOptions();
                /// produces the type of the current object but no subobjects
                Type * getCurrentType();

        private:
                std::stack< MemberIterator * > objStack;
        };
} // namespace ResolvExpr

namespace ast {
        // AST class types
        class Designation;
        struct InitAlternative;
        class Type;

        /// Iterates members of a type by initializer
        class MemberIterator {
        public:
                virtual ~MemberIterator() {}

                /// Internal set position based on iterator ranges
                virtual void setPosition( 
                        std::deque< ptr< Expr > >::const_iterator it, 
                        std::deque< ptr< Expr > >::const_iterator end ) = 0;

                /// walks the current object using the given designators as a guide
                void setPosition( const std::deque< ptr< Expr > > & designators ) {
                        setPosition( designators.begin(), designators.end() );
                }

                /// retrieve the list of possible (Type,Designation) pairs for the current position in the 
                /// current object
                virtual std::deque< InitAlternative > operator* () const = 0;

                /// true if the iterator is not currently at the end
                virtual operator bool() const = 0;

                /// moves the iterator by one member in the current object
                virtual MemberIterator & bigStep() = 0;

                /// moves the iterator by one member in the current subobject
                virtual MemberIterator & smallStep() = 0;

                /// the type of the current object
                virtual const Type * getType() = 0;

                /// the type of the current subobject
                virtual const Type * getNext() = 0;
        
                /// helper for operator*; aggregates must add designator to each init alternative, but 
                /// adding designators in operator* creates duplicates
                virtual std::deque< InitAlternative > first() const = 0;
        };

        /// Builds initializer lists in resolution
        class CurrentObject final {
                std::vector< std::shared_ptr<MemberIterator> > objStack;
        
        public:
                CurrentObject() = default;
                CurrentObject( const CodeLocation & loc, const Type * type );

                /// resolves unresolved designation
                const Designation * findNext( const Designation * designation );
                /// sets current position using the resolved designation
                void setNext( const ast::Designation * designation );
                /// steps to next sub-object of current object
                void increment();
                /// sets new current object for the duration of this brace-enclosed intializer-list
                void enterListInit( const CodeLocation & loc );
                /// restores previous current object
                void exitListInit();
                /// produces a list of alternatives (Type *, Designation *) for the current sub-object's 
                /// initializer.
                std::deque< InitAlternative > getOptions();
                /// produces the type of the current object but no subobjects
                const Type * getCurrentType();
        };
} // namespace ast

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