/* -*-C++-*- */
/*
 * Predicates.
 *
 * Copyright (C) 2003 Carnegie Mellon University and Rutgers University
 *
 * Permission is hereby granted to distribute this software for
 * non-commercial research purposes, provided that this copyright
 * notice is included with any such distribution.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
 * EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
 * SOFTWARE IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU
 * ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
 *
 * $Id: predicates.h,v 1.2 2004/03/06 03:23:55 hakan Exp $
 */
#ifndef PREDICATES_H
#define PREDICATES_H

#include <config.h>
#include "types.h"
#include "hashing.h"
#include <iostream>
#include <map>
#include <string>
#include <vector>


/* Predicate index. */
typedef int Predicate;


/* ====================================================================== */
/* PredicateSet */

/* Set of predicate declarations. */
struct PredicateSet : public hashing::hash_set<Predicate> {
};


/* ====================================================================== */
/* PredicateTable */

/*
 * Predicate table.
 */
struct PredicateTable {
  /* Constructs an empty predicate table. */
  PredicateTable() : first_(next) {}

  /* Adds a predicate with the given name to this table and returns
     the predicate. */
  Predicate add_predicate(const std::string& name);

  /* Returns the predicate with the given name.  If no predicate with
     the given name exists, false is returned in the second part of
     the result. */
  std::pair<Predicate, bool> find_predicate(const std::string& name) const;

  /* Returns the first predicate of this predicate table. */
  Predicate first_predicate() const { return first_; }

  /* Returns the last predicate of this predicate table. */
  Predicate last_predicate() const { return first_ + names_.size() - 1; }

  /* Adds a parameter with the given type to the given predicate. */
  void add_parameter(Predicate predicate, Type type) {
    parameters_[predicate - first_].push_back(type);
  }

  /* Returns the name of the given predicate. */
  const std::string& name(Predicate predicate) const {
    return names_[predicate - first_];
  }

  /* Returns the arity of the given predicate. */
  size_t arity(Predicate predicate) const {
    return parameters_[predicate - first_].size();
  }

  /* Returns the ith parameter type of the given predicate. */
  Type parameter(Predicate predicate, size_t i) const {
    return parameters_[predicate - first_][i];
  }

  /* Makes the given predicate dynamic. */
  void make_dynamic(Predicate predicate) {
    static_predicates_.erase(predicate);
  }

  /* Tests if a predicate is static. */
  bool static_predicate(Predicate predicate) const {
    return static_predicates_.find(predicate) != static_predicates_.end();
  }

  /* Return the static predicates. */
  PredicateSet static_predicates(Predicate predicate) const {
    return static_predicates_;
  }

  /* Print the static predicates. */
  void print_static_predicates(std::ostream& os) const {
    for (PredicateSet::const_iterator ai = static_predicates_.begin(); ai != static_predicates_.end(); ai++) {
      print_predicate(os,*ai);
    }    
  }




  /* Prints the given predicate on the given stream. */
  void print_predicate(std::ostream& os, Predicate predicate) const;

private:
  /* Next predicate. */
  static Predicate next;

  /* The first predicate. */
  Predicate first_;
  /* Predicate names. */
  std::vector<std::string> names_;
  /* Mapping of predicate names to predicates. */
  std::map<std::string, Predicate> predicates_;
  /* Predicate parameters. */
  std::vector<TypeList> parameters_;
  /* Static predicates. */
  PredicateSet static_predicates_;
};


#endif /* PREDICATES_H */