// static
RewriteResponse TheorySetsRewriter::preRewrite(TNode node) {
NodeManager* nm = NodeManager::currentNM();
// do nothing
if(node.getKind() == kind::EQUAL && node[0] == node[1])
return RewriteResponse(REWRITE_DONE, nm->mkConst(true));
// Further optimization, if constants but differing ones
return RewriteResponse(REWRITE_DONE, node);
}
RewriteResponse TheorySepRewriter::postRewrite(TNode node) {
Trace("sep-postrewrite") << "Sep::postRewrite start " << node << std::endl;
Node retNode = node;
switch (node.getKind()) {
case kind::SEP_LABEL: {
if( node[0].getKind()==kind::SEP_PTO ){
Node s = NodeManager::currentNM()->mkNode( kind::SINGLETON, node[0][0] );
if( node[1]!=s ){
Node c1 = node[1].eqNode( s );
Node c2 = NodeManager::currentNM()->mkNode( kind::SEP_LABEL, NodeManager::currentNM()->mkNode( kind::SEP_PTO, node[0][0], node[0][1] ), s );
retNode = NodeManager::currentNM()->mkNode( kind::AND, c1, c2 );
}
}
if( node[0].getKind()==kind::SEP_EMP ){
retNode = node[1].eqNode( NodeManager::currentNM()->mkConst(EmptySet(node[1].getType().toType())) );
}
break;
}
case kind::SEP_PTO: {
break;
}
case kind::SEP_STAR: {
//flatten
std::vector< Node > s_children;
std::vector< Node > ns_children;
getStarChildren( node, s_children, ns_children );
if( !s_children.empty() ){
Node schild;
if( s_children.size()==1 ) {
schild = s_children[0];
}else{
schild = NodeManager::currentNM()->mkNode( kind::SEP_STAR, s_children );
}
ns_children.push_back( schild );
}
Assert( !ns_children.empty() );
if( ns_children.size()==1 ){
retNode = ns_children[0];
}else{
retNode = NodeManager::currentNM()->mkNode( kind::AND, ns_children );
}
break;
}
case kind::EQUAL:
case kind::IFF: {
if(node[0] == node[1]) {
return RewriteResponse(REWRITE_DONE, NodeManager::currentNM()->mkConst(true));
}
else if (node[0].isConst() && node[1].isConst()) {
return RewriteResponse(REWRITE_DONE, NodeManager::currentNM()->mkConst(false));
}
if (node[0] > node[1]) {
Node newNode = NodeManager::currentNM()->mkNode(node.getKind(), node[1], node[0]);
return RewriteResponse(REWRITE_DONE, newNode);
}
break;
}
default:
break;
}
if( node!=retNode ){
Trace("sep-rewrite") << "Sep::rewrite : " << node << " -> " << retNode << std::endl;
}
return RewriteResponse(node==retNode ? REWRITE_DONE : REWRITE_AGAIN_FULL, retNode);
}
// static
RewriteResponse TheorySetsRewriter::postRewrite(TNode node) {
NodeManager* nm = NodeManager::currentNM();
switch(node.getKind()) {
case kind::IN: {
if(!node[0].isConst() || !node[1].isConst())
break;
// both are constants
bool isMember = checkConstantMembership(node[0], node[1]);
return RewriteResponse(REWRITE_DONE, nm->mkConst(isMember));
}
case kind::SUBSET: {
// rewrite (A subset-or-equal B) as (A union B = B)
TNode A = node[0];
TNode B = node[1];
return RewriteResponse(REWRITE_AGAIN,
nm->mkNode(kind::EQUAL,
nm->mkNode(kind::UNION, A, B),
B) );
}//kind::SUBSET
case kind::EQUAL:
case kind::IFF: {
//rewrite: t = t with true (t term)
//rewrite: c = c' with c different from c' false (c, c' constants)
//otherwise: sort them
if(node[0] == node[1]) {
Trace("sets-postrewrite") << "Sets::postRewrite returning true" << std::endl;
return RewriteResponse(REWRITE_DONE, nm->mkConst(true));
}
else if (node[0].isConst() && node[1].isConst()) {
Trace("sets-postrewrite") << "Sets::postRewrite returning false" << std::endl;
return RewriteResponse(REWRITE_DONE, nm->mkConst(false));
}
else if (node[0] > node[1]) {
Node newNode = nm->mkNode(node.getKind(), node[1], node[0]);
Trace("sets-postrewrite") << "Sets::postRewrite returning " << newNode << std::endl;
return RewriteResponse(REWRITE_DONE, newNode);
}
break;
}
case kind::UNION:
case kind::INTERSECTION: {
if(node[0] == node[1]) {
Trace("sets-postrewrite") << "Sets::postRewrite returning " << node[0] << std::endl;
return RewriteResponse(REWRITE_DONE, node[0]);
} else if (node[0] > node[1]) {
Node newNode = nm->mkNode(node.getKind(), node[1], node[0]);
Trace("sets-postrewrite") << "Sets::postRewrite returning " << newNode << std::endl;
return RewriteResponse(REWRITE_DONE, newNode);
}
break;
}
default:
break;
}//switch(node.getKind())
// This default implementation
return RewriteResponse(REWRITE_DONE, node);
}