--- /dev/null
+package org.simantics.scl.compiler.elaboration.query;
+
+import gnu.trove.map.hash.THashMap;
+import gnu.trove.set.hash.THashSet;
+
+import java.util.Collection;
+import java.util.Set;
+
+import org.simantics.scl.compiler.elaboration.contexts.ReplaceContext;
+import org.simantics.scl.compiler.elaboration.contexts.TypingContext;
+import org.simantics.scl.compiler.elaboration.expressions.EVariable;
+import org.simantics.scl.compiler.elaboration.expressions.QueryTransformer;
+import org.simantics.scl.compiler.elaboration.expressions.Variable;
+import org.simantics.scl.compiler.elaboration.expressions.VariableProcedure;
+import org.simantics.scl.compiler.elaboration.query.compilation.ConstraintCollectionContext;
+import org.simantics.scl.compiler.elaboration.query.compilation.DerivateException;
+import org.simantics.scl.compiler.elaboration.query.compilation.UnsolvableQueryException;
+import org.simantics.scl.compiler.elaboration.relations.LocalRelation;
+import org.simantics.scl.compiler.elaboration.relations.SCLRelation;
+import org.simantics.scl.compiler.types.Types;
+import org.simantics.scl.compiler.types.kinds.Kinds;
+
+public class QExists extends QAbstractModifier {
+ Variable[] variables;
+
+ public QExists(Variable[] variables, Query query) {
+ super(query);
+ this.variables = variables;
+ }
+
+ public QExists(Collection<Variable> variables, Query query) {
+ this(variables.toArray(new Variable[variables.size()]), query);
+ }
+
+ @Override
+ public void collectFreeVariables(THashSet<Variable> vars) {
+ super.collectFreeVariables(vars);
+ for(Variable variable : variables)
+ vars.remove(variable);
+ }
+
+ @Override
+ public void checkType(TypingContext context) {
+ for(Variable var : variables)
+ var.setType(Types.metaVar(Kinds.STAR));
+ super.checkType(context);
+ }
+
+ @Override
+ public void collectConstraints(ConstraintCollectionContext context) throws UnsolvableQueryException {
+ for(Variable variable : variables)
+ context.addVariable(variable);
+ query.collectConstraints(context);
+ }
+
+ @Override
+ public Diff[] derivate(THashMap<LocalRelation, Diffable> diffables) throws DerivateException {
+ Diff[] result = query.derivate(diffables);
+ for(int i=0;i<result.length;++i)
+ result[i].query = new QExists(variables, result[i].query);
+ return result;
+ }
+
+ @Override
+ public Query replace(ReplaceContext context) {
+ Variable[] newVariables = new Variable[variables.length];
+ for(int i=0;i<variables.length;++i) {
+ Variable variable = variables[i];
+ Variable newVariable = new Variable(variable.getName(), variable.getType().replace(context.tvarMap));
+ newVariables[i] = newVariable;
+ context.varMap.put(variable, new EVariable(newVariable));
+ }
+ Query result = new QExists(newVariables, query.replace(context));
+ for(Variable v : variables)
+ context.varMap.remove(v);
+ return result;
+ }
+
+ @Override
+ public Query removeRelations(Set<SCLRelation> relations) {
+ Query newQuery = query.removeRelations(relations);
+ if(newQuery == query)
+ return this;
+ else if(newQuery == EMPTY_QUERY)
+ return EMPTY_QUERY;
+ else
+ return new QExists(variables, newQuery);
+ }
+
+ @Override
+ public void accept(QueryVisitor visitor) {
+ visitor.visit(this);
+ }
+
+ @Override
+ public void forVariables(VariableProcedure procedure) {
+ for(Variable variable : variables)
+ procedure.execute(location, variable);
+ super.forVariables(procedure);
+ }
+
+ @Override
+ public Query accept(QueryTransformer transformer) {
+ return transformer.transform(this);
+ }
+
+}