//---------------------------------------------------------------------------
void SemanticAnalysis::transform(const SPARQLParser& input,QueryGraph& output)
// Perform the transformation
{
output.clear();
if (!transformSubquery(dict,diffIndex,input.getPatterns(),output.getQuery())) {
// A constant could not be resolved. This will produce an empty result
output.markAsKnownEmpty();
return;
}
// Compute the edges
output.constructEdges();
// Add the projection entry
for (SPARQLParser::projection_iterator iter=input.projectionBegin(),limit=input.projectionEnd();iter!=limit;++iter){
output.addProjection(*iter);
}
// Add the path projection entry
for (SPARQLParser::projection_iterator iter=input.pathprojectionBegin(), limit=input.pathprojectionEnd(); iter!=limit;++iter){
output.addProjection(*iter);
}
// Set the duplicate handling
switch (input.getProjectionModifier()) {
case SPARQLParser::Modifier_None: output.setDuplicateHandling(QueryGraph::AllDuplicates); break;
case SPARQLParser::Modifier_Distinct: output.setDuplicateHandling(QueryGraph::NoDuplicates); break;
case SPARQLParser::Modifier_Reduced: output.setDuplicateHandling(QueryGraph::ReducedDuplicates); break;
case SPARQLParser::Modifier_Count: output.setDuplicateHandling(QueryGraph::CountDuplicates); break;
case SPARQLParser::Modifier_Duplicates: output.setDuplicateHandling(QueryGraph::ShowDuplicates); break;
}
// Set the query form
switch (input.getQueryForm()){
case SPARQLParser::Select: output.setQueryForm(QueryGraph::Select); break;
case SPARQLParser::Describe: output.setQueryForm(QueryGraph::Describe); break;
case SPARQLParser::Ask: case SPARQLParser::Construct: break;
}
// Order by clause
for (SPARQLParser::order_iterator iter=input.orderBegin(),limit=input.orderEnd();iter!=limit;++iter) {
QueryGraph::Order o;
if (~(*iter).id) {
if (!binds(input.getPatterns(),(*iter).id))
continue;
o.id=(*iter).id;
} else {
o.id=~0u;
}
o.descending=(*iter).descending;
output.addOrder(o);
}
// Set the limit
output.setLimit(input.getLimit());
}
