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/********************* */
/*! \file theory_builtin.cpp
** \verbatim
** Original author: mdeters
** Major contributors: none
** Minor contributors (to current version): none
** This file is part of the CVC4 prototype.
** Copyright (c) 2009, 2010 The Analysis of Computer Systems Group (ACSys)
** Courant Institute of Mathematical Sciences
** New York University
** See the file COPYING in the top-level source directory for licensing
** information.\endverbatim
**
** \brief Implementation of the builtin theory.
**
** Implementation of the builtin theory.
**/
#include "theory/builtin/theory_builtin.h"
#include "theory/theory_engine.h"
#include "expr/kind.h"
using namespace std;
namespace CVC4 {
namespace theory {
namespace builtin {
Node TheoryBuiltin::blastDistinct(TNode in) {
Debug("theory-rewrite") << "TheoryBuiltin::blastDistinct: "
<< in << std::endl;
Assert(in.getKind() == kind::DISTINCT);
if(in.getNumChildren() == 2) {
// if this is the case exactly 1 != pair will be generated so the
// AND is not required
Node eq = NodeManager::currentNM()->mkNode(in[0].getType().isBoolean() ?
kind::IFF : kind::EQUAL,
in[0], in[1]);
Node neq = NodeManager::currentNM()->mkNode(kind::NOT, eq);
return neq;
}
// assume that in.getNumChildren() > 2 => diseqs.size() > 1
vector<Node> diseqs;
for(TNode::iterator i = in.begin(); i != in.end(); ++i) {
TNode::iterator j = i;
while(++j != in.end()) {
Node eq = NodeManager::currentNM()->mkNode((*i).getType().isBoolean() ?
kind::IFF : kind::EQUAL,
*i, *j);
Node neq = NodeManager::currentNM()->mkNode(kind::NOT, eq);
diseqs.push_back(neq);
}
}
Node out = NodeManager::currentNM()->mkNode(kind::AND, diseqs);
return out;
}
RewriteResponse TheoryBuiltin::preRewrite(TNode in, bool topLevel) {
switch(in.getKind()) {
case kind::DISTINCT:
return RewriteComplete(blastDistinct(in));
case kind::EQUAL:
// EQUAL is a special case that should never end up here
Unreachable("TheoryBuiltin can't rewrite EQUAL !");
default:
return RewriteComplete(in);
}
}
Node TheoryBuiltin::getValue(TNode n, TheoryEngine* engine) {
switch(n.getKind()) {
case kind::VARIABLE:
// no variables that the builtin theory is responsible for
Unreachable();
case kind::EQUAL: { // 2 args
// has to be an EQUAL over tuples, since all others should be
// handled elsewhere
Assert(n[0].getKind() == kind::TUPLE &&
n[1].getKind() == kind::TUPLE);
return NodeManager::currentNM()->
mkConst( getValue(n[0], engine) == getValue(n[1], engine) );
}
case kind::TUPLE: { // 2+ args
NodeBuilder<> nb(kind::TUPLE);
for(TNode::iterator i = n.begin(),
iend = n.end();
i != iend;
++i) {
nb << engine->getValue(*i);
}
return Node(nb);
}
default:
// all other "builtins" should have been rewritten away or handled
// by theory engine, or handled elsewhere.
Unhandled(n.getKind());
}
}
}/* CVC4::theory::builtin namespace */
}/* CVC4::theory */
}/* CVC4 namespace */
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