Typeclass.hxx

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#ifndef TYPECLASS_HXX
#define TYPECLASS_HXX

/**************************************************************************
 *
 * Copyright (C) 2008, Johns Hopkins University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 *   - Redistributions of source code must contain the above 
 *     copyright notice, this list of conditions, and the following
 *     disclaimer. 
 *
 *   - Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions, and the following
 *     disclaimer in the documentation and/or other materials 
 *     provided with the distribution.
 *
 *   - Neither the names of the copyright holders nor the names of any
 *     of any contributors may be used to endorse or promote products
 *     derived from this software without specific prior written
 *     permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 **************************************************************************/

#include <stdlib.h>
#include <dirent.h>
#include <fstream>
#include <iostream>
#include <string>
#include <set>

#include "AST.hxx"
#include "Type.hxx"

struct TypeScheme;
struct TCConstraints;

typedef Type Typeclass;
typedef Typeclass Constraint; 
typedef TCConstraints Constraints; 

typedef TypeSet TypeclassSet;
typedef TypeSet ConstraintSet;

struct Instance {
  boost::shared_ptr<TypeScheme> ts;
  boost::shared_ptr<AST> ast;
  
  Instance(boost::shared_ptr<TypeScheme> _ts, boost::shared_ptr<AST>_ins)
  {
    ts = _ts;
    ast = _ins;
  }
  
  static inline boost::shared_ptr<Instance>
  make(boost::shared_ptr<TypeScheme> _ts, boost::shared_ptr<AST>_ins) {
    Instance *tmp = new Instance(_ts, _ins);
    return boost::shared_ptr<Instance>(tmp);
  }

  bool equals(boost::shared_ptr<Instance> ins, 
              boost::shared_ptr<const InstEnvironment > instEnv) const;
  bool overlaps(boost::shared_ptr<Instance> ins) const;
  bool satisfies(boost::shared_ptr<Typeclass> pred, 
                 boost::shared_ptr<const InstEnvironment > instEnv) const;
  std::string asString() const;

  std::string asXML();
  void asXML(sherpa::INOstream &out);

  int operator<(const struct Instance& rhs) const {
    return (asString() < rhs.asString());
  }
};

// Impose a canonical sort order on pointers to Instance, so that
// operations involving sets of Instance pointers will procede in a
// deterministic order
static int operator<(const boost::shared_ptr<Instance>& lhs, 
                     const boost::shared_ptr<Instance>& rhs)
{
  return (*lhs) < (*rhs);
}



/* Type class constraints */
 
struct TCConstraints {
  // Type class predicates (which are, in turn, instances of Type
  TypeSet pred;
  typedef TypeSet::iterator iterator;
  
  TCConstraints()
  {
  }

  bool empty() const {
    return pred.empty();
  }

  size_t size() const {
    return pred.size();
  }

  void addPred(boost::shared_ptr<Typeclass> tc);
  void clearPred(boost::shared_ptr<Constraint> ct);

  void normalize();
  
  bool contains(boost::shared_ptr<Typeclass> tc);

  void collectAllFnDeps(TypeSet& fnDeps);
  
  // Compute the closure of all functional dependencies 
  // supplied in the vector
  static void close(TypeSet& closure,
                    const TypeSet& fnDeps);
  void clearHintsOnPreds(boost::shared_ptr<Trail> trail);  

  iterator begin() {
    return pred.begin();
  }
  iterator end() {
    return pred.end();
  }

  static inline boost::shared_ptr<TCConstraints>
  make() {
    TCConstraints *tmp = new TCConstraints();
    return boost::shared_ptr<TCConstraints>(tmp);
  }
};


#endif /* TYPECLASS_HXX */

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