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/********************* */
/*! \file dynamic_rewrite.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Andres Noetzli
** This file is part of the CVC4 project.
** Copyright (c) 2009-2018 by the authors listed in the file AUTHORS
** in the top-level source directory) and their institutional affiliations.
** All rights reserved. See the file COPYING in the top-level source
** directory for licensing information.\endverbatim
**
** \brief Implementation of dynamic_rewriter
**/
#include "theory/quantifiers/dynamic_rewrite.h"
#include "theory/rewriter.h"
using namespace std;
using namespace CVC4::kind;
namespace CVC4 {
namespace theory {
namespace quantifiers {
DynamicRewriter::DynamicRewriter(const std::string& name,
context::UserContext* u)
: d_equalityEngine(u, "DynamicRewriter::" + name, true), d_rewrites(u)
{
d_equalityEngine.addFunctionKind(kind::APPLY_UF);
}
void DynamicRewriter::addRewrite(Node a, Node b)
{
Trace("dyn-rewrite") << "Dyn-Rewriter : " << a << " == " << b << std::endl;
if (a == b)
{
Trace("dyn-rewrite") << "...equal." << std::endl;
return;
}
// add to the equality engine
Node ai = toInternal(a);
Node bi = toInternal(b);
if (ai.isNull() || bi.isNull())
{
Trace("dyn-rewrite") << "...not internalizable." << std::endl;
return;
}
Trace("dyn-rewrite-debug") << "Internal : " << ai << " " << bi << std::endl;
Trace("dyn-rewrite-debug") << "assert eq..." << std::endl;
Node eq = ai.eqNode(bi);
d_rewrites.push_back(eq);
d_equalityEngine.assertEquality(eq, true, eq);
Assert(d_equalityEngine.consistent());
Trace("dyn-rewrite-debug") << "Finished" << std::endl;
}
bool DynamicRewriter::areEqual(Node a, Node b)
{
if (a == b)
{
return true;
}
Trace("dyn-rewrite-debug") << "areEqual? : " << a << " " << b << std::endl;
// add to the equality engine
Node ai = toInternal(a);
Node bi = toInternal(b);
if (ai.isNull() || bi.isNull())
{
Trace("dyn-rewrite") << "...not internalizable." << std::endl;
return false;
}
Trace("dyn-rewrite-debug") << "internal : " << ai << " " << bi << std::endl;
d_equalityEngine.addTerm(ai);
d_equalityEngine.addTerm(bi);
Trace("dyn-rewrite-debug") << "...added terms" << std::endl;
return d_equalityEngine.areEqual(ai, bi);
}
Node DynamicRewriter::toInternal(Node a)
{
std::map<Node, Node>::iterator it = d_term_to_internal.find(a);
if (it != d_term_to_internal.end())
{
return it->second;
}
Node ret = a;
if (!a.isVar())
{
std::vector<Node> children;
if (a.hasOperator())
{
Node op = a.getOperator();
if (a.getKind() != APPLY_UF)
{
op = d_ois_trie[op].getSymbol(a);
// if this term involves an argument that is not of first class type,
// we cannot reason about it. This includes operators like str.in-re.
if (op.isNull())
{
return Node::null();
}
}
children.push_back(op);
}
for (const Node& ca : a)
{
Node cai = toInternal(ca);
if (cai.isNull())
{
return Node::null();
}
children.push_back(cai);
}
if (!children.empty())
{
if (children.size() == 1)
{
ret = children[0];
}
else
{
ret = NodeManager::currentNM()->mkNode(APPLY_UF, children);
}
}
}
d_term_to_internal[a] = ret;
d_internal_to_term[ret] = a;
return ret;
}
Node DynamicRewriter::toExternal(Node ai)
{
std::map<Node, Node>::iterator it = d_internal_to_term.find(ai);
if (it != d_internal_to_term.end())
{
return it->second;
}
return Node::null();
}
Node DynamicRewriter::OpInternalSymTrie::getSymbol(Node n)
{
std::vector<TypeNode> ctypes;
for (const Node& cn : n)
{
ctypes.push_back(cn.getType());
}
ctypes.push_back(n.getType());
OpInternalSymTrie* curr = this;
for (unsigned i = 0, size = ctypes.size(); i < size; i++)
{
// cannot handle certain types (e.g. regular expressions or functions)
if (!ctypes[i].isFirstClass())
{
return Node::null();
}
curr = &(curr->d_children[ctypes[i]]);
}
if (!curr->d_sym.isNull())
{
return curr->d_sym;
}
// make UF operator
TypeNode utype;
if (ctypes.size() == 1)
{
utype = ctypes[0];
}
else
{
utype = NodeManager::currentNM()->mkFunctionType(ctypes);
}
Node f = NodeManager::currentNM()->mkSkolem(
"ufd", utype, "internal op for dynamic_rewriter");
curr->d_sym = f;
return f;
}
} /* CVC4::theory::quantifiers namespace */
} /* CVC4::theory namespace */
} /* CVC4 namespace */
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