/**
* Parse the type attribute of <Expr>, <Ind>, <Data> and <Var> elements.
*
* @param element The element whose type attribute should be parsed.
* @return A unique numeric identifier generated by the type system.
* @throws ParseException Thrown if the type specified in the type attribute is invalid.
*/
private int parseTypeAttribute(Element element) throws ParseException {
Attribute type = element.getAttribute(tagNames.TYPE);
int typeid = Types.IOBJECT;
if (type != null) {
typeid = Types.typeID(type.getValue().trim());
if (typeid == -1) {
throw new ParseException("Type " + type.getValue().trim() + " is not defined.");
}
}
return typeid;
}
/**
* A method to find the normalized types for each variable in the clause.
*
* @return A hash table containing the normalized type for each variable in the current clause.
* @throws ParseException A ParseException is thrown a variable does not have a normalized form
* (type that is an intersection of all given types); since Nothing inherits from all types
* this should never occur.
*/
private Hashtable<Integer, Integer> buildTypeTable() throws ParseException {
Hashtable<Integer, Integer> ht = new Hashtable<Integer, Integer>();
Enumeration<Integer> e = varClasses.keys();
while (e.hasMoreElements()) {
int key = e.nextElement();
Vector<Integer> value = varClasses.get(key);
int[] types = new int[value.size()];
for (int i = 0; i < types.length; i++) {
types[i] = ((Integer) value.get(i)).intValue();
}
int type = Types.greatestLowerBound(types);
ht.put(key, type);
}
return ht;
}