model.cpp

/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */

/*
 *  Main authors:
 *     Guido Tack <guido.tack@monash.edu>
 */

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <minizinc/model.hh>
#include <minizinc/flatten_internal.hh>
#include <minizinc/astexception.hh>
#include <minizinc/prettyprinter.hh>

#undef MZN_DEBUG_FUNCTION_REGISTRY

namespace MiniZinc {
  
  Model::Model(void) : _parent(NULL), _solveItem(NULL), _outputItem(NULL), _failed(false) {
    GC::add(this);
  }

  Model::~Model(void) {
    for (unsigned int j=0; j<_items.size(); j++) {
      Item* i = _items[j];
      if (IncludeI* ii = i->dyn_cast<IncludeI>()) {
        if (ii->own() && ii->m()) {
          delete ii->m();
          ii->m(NULL);
        }
      }
    }
    GC::remove(this);
  }

  VarDeclIterator
  Model::begin_vardecls(void) {
    return VarDeclIterator(this, begin());
  }
  VarDeclIterator
  Model::end_vardecls(void) {
    return VarDeclIterator(this, end());
  }
  ConstraintIterator
  Model::begin_constraints(void) {
    return ConstraintIterator(this, begin());
  }
  ConstraintIterator
  Model::end_constraints(void) {
    return ConstraintIterator(this, end());
  }
  
  SolveI*
  Model::solveItem() {
    return _solveItem;
  }
  
  OutputI*
  Model::outputItem() {
    return _outputItem;
  }
  
  void
  Model::registerFn(EnvI& env, FunctionI* fi) {
    Model* m = this;
    while (m->_parent)
      m = m->_parent;
    FnMap::iterator i_id = m->fnmap.find(fi->id());
    if (i_id == m->fnmap.end()) {
      // new element
      std::vector<FunctionI*> v; v.push_back(fi);
      m->fnmap.insert(std::pair<ASTString,std::vector<FunctionI*> >(fi->id(),v));
    } else {
      // add to list of existing elements
      std::vector<FunctionI*>& v = i_id->second;
      for (unsigned int i=0; i<v.size(); i++) {
        if (v[i]->params().size() == fi->params().size()) {
          bool alleq=true;
          for (unsigned int j=0; j<fi->params().size(); j++) {
            if (v[i]->params()[j]->type() != fi->params()[j]->type()) {
              alleq=false; break;
            }
          }
          if (alleq) {
            if (v[i]->e() && fi->e()) {
              throw InternalError(
                              "function with the same type already defined in "
                              +v[i]->loc().toString());
              
            } else {
              if (fi->e())
                v[i] = fi;
              return;
            }
          }
        }
      }
      v.push_back(fi);
    }
  }

  FunctionI*
  Model::matchFn(EnvI& env, const ASTString& id,
                 const std::vector<Type>& t) {
    if (id==constants().var_redef->id())
      return constants().var_redef;
    Model* m = this;
    while (m->_parent)
      m = m->_parent;
    FnMap::iterator i_id = m->fnmap.find(id);
    if (i_id == m->fnmap.end()) {
      return NULL;
    }
    std::vector<FunctionI*>& v = i_id->second;
    for (unsigned int i=0; i<v.size(); i++) {
      FunctionI* fi = v[i];
#ifdef MZN_DEBUG_FUNCTION_REGISTRY
      std::cerr << "try " << *fi;
#endif
      if (fi->params().size() == t.size()) {
        bool match=true;
        for (unsigned int j=0; j<t.size(); j++) {
          if (!t[j].isSubtypeOf(fi->params()[j]->type())) {
#ifdef MZN_DEBUG_FUNCTION_REGISTRY
            std::cerr << t[j].toString() << " does not match "
            << fi->params()[j]->type().toString() << "\n";
#endif
            match=false;
            break;
          }
        }
        if (match) {
          return fi;
        }
      }
    }
    return NULL;
  }

  namespace {
    class FunSort {
    public:
      bool operator()(FunctionI* x, FunctionI* y) const {
        if (x->params().size() < y->params().size())
          return true;
        if (x->params().size() == y->params().size()) {
          for (unsigned int i=0; i<x->params().size(); i++) {
            switch (x->params()[i]->type().cmp(y->params()[i]->type())) {
            case -1: return true;
            case 1: return false;
            }
          }
        }
        return false;
      }
    };
  }

  void
  Model::sortFn(void) {
    Model* m = this;
    while (m->_parent)
      m = m->_parent;
    FunSort funsort;
    for (FnMap::iterator it=m->fnmap.begin(); it!=m->fnmap.end(); ++it) {
      std::sort(it->second.begin(),it->second.end(),funsort);
    }
  }

  FunctionI*
  Model::matchFn(EnvI& env, const ASTString& id,
                 const std::vector<Expression*>& args) const {
    if (id==constants().var_redef->id())
      return constants().var_redef;
    const Model* m = this;
    while (m->_parent)
      m = m->_parent;
    FnMap::const_iterator it = m->fnmap.find(id);
    if (it == m->fnmap.end()) {
      return NULL;
    }
    const std::vector<FunctionI*>& v = it->second;
    std::vector<FunctionI*> matched;
    Expression* botarg = NULL;
    for (unsigned int i=0; i<v.size(); i++) {
      FunctionI* fi = v[i];
#ifdef MZN_DEBUG_FUNCTION_REGISTRY
      std::cerr << "try " << *fi;
#endif
      if (fi->params().size() == args.size()) {
        bool match=true;
        for (unsigned int j=0; j<args.size(); j++) {
          if (!args[j]->type().isSubtypeOf(fi->params()[j]->type())) {
#ifdef MZN_DEBUG_FUNCTION_REGISTRY
            std::cerr << args[j]->type().toString() << " does not match "
            << fi->params()[j]->type().toString() << "\n";
#endif
            match=false;
            break;
          }
          if (args[j]->type().isbot() && fi->params()[j]->type().bt()!=Type::BT_TOP) {
            botarg = args[j];
          }
        }
        if (match) {
          if (botarg)
            matched.push_back(fi);
          else
            return fi;
        }
      }
    }
    if (matched.empty())
      return NULL;
    if (matched.size()==1)
      return matched[0];
    Type t = matched[0]->ti()->type();
    t.ti(Type::TI_PAR);
    for (unsigned int i=1; i<matched.size(); i++) {
      if (!t.isSubtypeOf(matched[i]->ti()->type()))
        throw TypeError(env, botarg->loc(), "ambiguous overloading on return type of function");
    }
    return matched[0];
  }
  
  FunctionI*
  Model::matchFn(EnvI& env, Call* c) const {
    if (c->id()==constants().var_redef->id())
      return constants().var_redef;
    const Model* m = this;
    while (m->_parent)
      m = m->_parent;
    FnMap::const_iterator it = m->fnmap.find(c->id());
    if (it == m->fnmap.end()) {
      return NULL;
    }
    const std::vector<FunctionI*>& v = it->second;
    std::vector<FunctionI*> matched;
    Expression* botarg = NULL;
    for (unsigned int i=0; i<v.size(); i++) {
      FunctionI* fi = v[i];
#ifdef MZN_DEBUG_FUNCTION_REGISTRY
      std::cerr << "try " << *fi;
#endif
      if (fi->params().size() == c->args().size()) {
        bool match=true;
        for (unsigned int j=0; j<c->args().size(); j++) {
          if (!c->args()[j]->type().isSubtypeOf(fi->params()[j]->type())) {
#ifdef MZN_DEBUG_FUNCTION_REGISTRY
            std::cerr << c->args()[j]->type().toString() << " does not match "
            << fi->params()[j]->type().toString() << "\n";
            std::cerr << "Wrong argument is " << *c->args()[j];
#endif
            match=false;
            break;
          }
          if (c->args()[j]->type().isbot() && fi->params()[j]->type().bt()!=Type::BT_TOP) {
            botarg = c->args()[j];
          }
        }
        if (match) {
          if (botarg)
            matched.push_back(fi);
          else
            return fi;
        }
      }
    }
    if (matched.empty())
      return NULL;
    if (matched.size()==1)
      return matched[0];
    Type t = matched[0]->ti()->type();
    t.ti(Type::TI_PAR);
    for (unsigned int i=1; i<matched.size(); i++) {
      if (!t.isSubtypeOf(matched[i]->ti()->type()))
        throw TypeError(env, botarg->loc(), "ambiguous overloading on return type of function");
    }
    return matched[0];
  }

  Item*&
  Model::operator[] (int i) { assert(i < _items.size()); return _items[i]; }
  const Item*
  Model::operator[] (int i) const { assert(i < _items.size()); return _items[i]; }
  unsigned int
  Model::size(void) const { return _items.size(); }
  
  std::vector<Item*>::iterator
  Model::begin(void) { return _items.begin(); }

  std::vector<Item*>::const_iterator
  Model::begin(void) const { return _items.begin(); }

  std::vector<Item*>::iterator
  Model::end(void) { return _items.end(); }

  std::vector<Item*>::const_iterator
  Model::end(void) const { return _items.end(); }
  
  void
  Model::compact(void) {
    struct { bool operator() (const Item* i) {
      return i->removed();
    }} isremoved;
    _items.erase(remove_if(_items.begin(),_items.end(),isremoved),
                 _items.end());
  }
  
  void
  Model::fail(EnvI& env) {
    if (!_failed) {
      env.addWarning("model inconsistency detected");
      _failed = true;
      for (unsigned int i=0; i<_items.size(); i++)
        if (ConstraintI* ci = _items[i]->dyn_cast<ConstraintI>())
          ci->remove();
      ConstraintI* failedConstraint = new ConstraintI(Location().introduce(),constants().lit_false);
      _items.push_back(failedConstraint);
    }
  }

  bool Model::failed() const {
    return _failed;
  }
}