source: src/SynTree/TypeSubstitution.h@ 837a17c

//
// 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.
//
// TypeSubstitution.h --
//
// Author           : Richard C. Bilson
// Created On       : Mon May 18 07:44:20 2015
// Last Modified By : Rob Schluntz
// Last Modified On : Fri Apr 29 15:00:20 2016
// Update Count     : 2
//

#ifndef TYPESUBSTITUTION_H
#define TYPESUBSTITUTION_H

#include <map>
#include <set>
#include <cassert>

#include "SynTree/Mutator.h"
#include "SynTree/Declaration.h"
#include "SynTree/Expression.h"

class TypeSubstitution : public Mutator {
        typedef Mutator Parent;
  public:
        TypeSubstitution();
        template< typename FormalIterator, typename ActualIterator >
        TypeSubstitution( FormalIterator formalBegin, FormalIterator formalEnd, ActualIterator actualBegin );
        TypeSubstitution( const TypeSubstitution &other );
        virtual ~TypeSubstitution();

        TypeSubstitution &operator=( const TypeSubstitution &other );

        template< typename SynTreeClass > int apply( SynTreeClass *&input );
        template< typename SynTreeClass > int applyFree( SynTreeClass *&input );

        void add( std::string formalType, Type *actualType );
        void add( const TypeSubstitution &other );
        void remove( std::string formalType );
        Type *lookup( std::string formalType ) const;
        bool empty() const;

        template< typename FormalIterator, typename ActualIterator >
        void add( FormalIterator formalBegin, FormalIterator formalEnd, ActualIterator actualBegin );

        /// this function is unused...
        template< typename TypeInstListIterator >
        void extract( TypeInstListIterator begin, TypeInstListIterator end, TypeSubstitution &result );

        void normalize();

        void print( std::ostream &os, int indent = 0 ) const;
        TypeSubstitution *clone() const { return new TypeSubstitution( *this ); }
  private:
        virtual Type* mutate(TypeInstType *aggregateUseType);
        virtual Expression* mutate(NameExpr *nameExpr);

        /// Records type variable bindings from forall-statements
        template< typename TypeClass > Type *handleType( TypeClass *type );
        /// Records type variable bindings from forall-statements and instantiations of generic types
        template< typename TypeClass > Type *handleAggregateType( TypeClass *type );

        virtual Type* mutate(VoidType *basicType);
        virtual Type* mutate(BasicType *basicType);
        virtual Type* mutate(PointerType *pointerType);
        virtual Type* mutate(ArrayType *arrayType);
        virtual Type* mutate(FunctionType *functionType);
        virtual Type* mutate(StructInstType *aggregateUseType);
        virtual Type* mutate(UnionInstType *aggregateUseType);
        virtual Type* mutate(EnumInstType *aggregateUseType);
        virtual Type* mutate(TraitInstType *aggregateUseType);
        virtual Type* mutate(TupleType *tupleType);
        virtual Type* mutate(VarArgsType *varArgsType);

        // TODO: worry about traversing into a forall-qualified function type or type decl with assertions

        void initialize( const TypeSubstitution &src, TypeSubstitution &dest );

        typedef std::map< std::string, Type* > TypeEnvType;
        typedef std::map< std::string, Expression* > VarEnvType;
        typedef std::set< std::string > BoundVarsType;
        TypeEnvType typeEnv;
        VarEnvType varEnv;
        BoundVarsType boundVars;
        int subCount;
        bool freeOnly;
};

template< typename FormalIterator, typename ActualIterator >
void TypeSubstitution::add( FormalIterator formalBegin, FormalIterator formalEnd, ActualIterator actualBegin ) {
        // FormalIterator points to a TypeDecl
        // ActualIterator points to a Type
        FormalIterator formalIt = formalBegin;
        ActualIterator actualIt = actualBegin;
        for ( ; formalIt != formalEnd; ++formalIt, ++actualIt ) {
                if ( TypeDecl *formal = dynamic_cast< TypeDecl* >( *formalIt ) ) {
                        if ( TypeExpr *actual = dynamic_cast< TypeExpr* >( *actualIt ) ) {
                                if ( formal->get_name() != "" ) {
                                        TypeEnvType::iterator i = typeEnv.find( formal->get_name() );
                                        if ( i != typeEnv.end() ) {
                                                delete i->second;
                                        } // if
                                        typeEnv[ formal->get_name() ] = actual->get_type()->clone();
                                } // if
                        } else {
                                throw SemanticError( "Attempt to provide non-type parameter for type parameter", formal );
                        } // if
                } else {
                        // TODO: type check the formal and actual parameters
                        if ( (*formalIt)->get_name() != "" ) {
                                varEnv[ (*formalIt)->get_name() ] = (*actualIt)->clone();
                        } // if
                } // if
        } // for
}

template< typename FormalIterator, typename ActualIterator >
TypeSubstitution::TypeSubstitution( FormalIterator formalBegin, FormalIterator formalEnd, ActualIterator actualBegin )
{
        add( formalBegin, formalEnd, actualBegin );
}

template< typename SynTreeClass >
int TypeSubstitution::apply( SynTreeClass *&input ) {
        assert( input );
        subCount = 0;
        freeOnly = false;
        input = dynamic_cast< SynTreeClass *>( input->acceptMutator( *this ) );
        assert( input );
///     std::cout << "substitution result is: ";
///     newType->print( std::cout );
///     std::cout << std::endl;
        return subCount;
}

template< typename SynTreeClass >
int TypeSubstitution::applyFree( SynTreeClass *&input ) {
        assert( input );
        subCount = 0;
        freeOnly = true;
        input = dynamic_cast< SynTreeClass *>( input->acceptMutator( *this ) );
        assert( input );
///     std::cout << "substitution result is: ";
///     newType->print( std::cout );
///     std::cout << std::endl;
        return subCount;
}

template< typename TypeInstListIterator >
void TypeSubstitution::extract( TypeInstListIterator begin, TypeInstListIterator end, TypeSubstitution &result ) {
        // xxx - this function doesn't extract varEnv - is this intentional?
        while ( begin != end ) {
                TypeEnvType::iterator cur = typeEnv.find( (*begin++)->get_name() );
                if ( cur != typeEnv.end() ) {
                        result.typeEnv[ cur->first ] = cur->second;
                        typeEnv.erase( cur );
                } // if
        } // while
}

/// Instantiate each member of the context given the actual parameters specified, and store the
/// instantiations for use by the indexer
template< typename FormalIterator, typename ActualIterator, typename MemberIterator, typename OutputIterator >
void applySubstitution( FormalIterator formalBegin, FormalIterator formalEnd, ActualIterator actual, MemberIterator memberBegin, MemberIterator memberEnd, OutputIterator out ) {
        TypeSubstitution sub = TypeSubstitution( formalBegin, formalEnd, actual );
        for ( std::list< Declaration* >::iterator i = memberBegin; i != memberEnd; ++i ) {
                Declaration *newdecl = (*i)->clone();
                sub.apply( newdecl );
                *out++ = newdecl;
        } // for
}

std::ostream & operator<<( std::ostream & out, const TypeSubstitution & sub );

#endif // TYPESUBSTITUTION_H

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