/**
* Check the types of this cast. Check if the expression can be casted to the given type.
*
* @see de.unika.ipd.grgen.ast.BaseNode#typeCheckLocal()
*/
private boolean typeCheckLocal() {
TypeNode fromType = expr.getType();
if (fromType instanceof NodeTypeNode && type instanceof NodeTypeNode) {
// we support up- and down-casts, but no cross-casts of nodes
HashSet<TypeNode> supertypesOfFrom = new HashSet<TypeNode>();
((NodeTypeNode) fromType).doGetCompatibleToTypes(supertypesOfFrom);
HashSet<TypeNode> supertypesOfTo = new HashSet<TypeNode>();
((NodeTypeNode) type).doGetCompatibleToTypes(supertypesOfTo);
return fromType.equals(type)
|| supertypesOfFrom.contains(type)
|| supertypesOfTo.contains(fromType);
}
if (fromType instanceof EdgeTypeNode && type instanceof EdgeTypeNode) {
// we support up- and down-casts, but no cross-casts of edges
HashSet<TypeNode> supertypesOfFrom = new HashSet<TypeNode>();
((EdgeTypeNode) fromType).doGetCompatibleToTypes(supertypesOfFrom);
HashSet<TypeNode> supertypesOfTo = new HashSet<TypeNode>();
((EdgeTypeNode) type).doGetCompatibleToTypes(supertypesOfTo);
return fromType.equals(type)
|| supertypesOfFrom.contains(type)
|| supertypesOfTo.contains(fromType);
}
if (fromType instanceof ObjectTypeNode
&& !(type instanceof NodeTypeNode)
&& !(type instanceof EdgeTypeNode))
return true; // object is castable to anything besides nodes and edges
if (type instanceof ObjectTypeNode
&& !(fromType instanceof NodeTypeNode)
&& !(fromType instanceof EdgeTypeNode))
return true; // anything besides nodes and edges can be casted into an object
if (fromType instanceof ExternalTypeNode && type instanceof ExternalTypeNode) {
// we support up- and down-casts, but no cross-casts of external types
HashSet<TypeNode> supertypesOfFrom = new HashSet<TypeNode>();
((ExternalTypeNode) fromType).doGetCompatibleToTypes(supertypesOfFrom);
HashSet<TypeNode> supertypesOfTo = new HashSet<TypeNode>();
((ExternalTypeNode) type).doGetCompatibleToTypes(supertypesOfTo);
return fromType.equals(type)
|| supertypesOfFrom.contains(type)
|| supertypesOfTo.contains(fromType);
}
boolean result = fromType.isCastableTo(type);
if (!result) {
reportError("Illegal cast from \"" + expr.getType() + "\" to \"" + type + "\"");
}
return result;
}
