return _left.getType() instanceof NodeSetType ||
_right.getType() instanceof NodeSetType;
}
public Type typeCheck(SymbolTable stable) throws TypeCheckError {
Type tleft = _left.typeCheck(stable);
Type tright = _right.typeCheck(stable);
//bug fix # 2838, cast to reals if both are result tree fragments
if (tleft instanceof ResultTreeType &&
tright instanceof ResultTreeType )
{
_right = new CastExpr(_right, Type.Real);
_left = new CastExpr(_left, Type.Real);
return _type = Type.Boolean;
}
// If one is of reference type, then convert the other too
if (hasReferenceArgs()) {
Type type = null;
Type typeL = null;
Type typeR = null;
if (tleft instanceof ReferenceType) {
if (_left instanceof VariableRefBase) {
VariableRefBase ref = (VariableRefBase)_left;
VariableBase var = ref.getVariable();
typeL = var.getType();
}
}
if (tright instanceof ReferenceType) {
if (_right instanceof VariableRefBase) {
VariableRefBase ref = (VariableRefBase)_right;
VariableBase var = ref.getVariable();
typeR = var.getType();
}
}
// bug fix # 2838
if (typeL == null)
type = typeR;
else if (typeR == null)
type = typeL;
else {
type = Type.Real;
}
if (type == null) type = Type.Real;
_right = new CastExpr(_right, type);
_left = new CastExpr(_left, type);
return _type = Type.Boolean;
}
if (hasNodeSetArgs()) {
// Ensure that the node-set is the left argument
if (tright instanceof NodeSetType) {
final Expression temp = _right; _right = _left; _left = temp;
_op = (_op == Operators.GT) ? Operators.LT :
(_op == Operators.LT) ? Operators.GT :
(_op == Operators.GE) ? Operators.LE : Operators.GE;
tright = _right.getType();
}
// Promote nodes to node sets
if (tright instanceof NodeType) {
_right = new CastExpr(_right, Type.NodeSet);
}
// Promote integer to doubles to have fewer compares
if (tright instanceof IntType) {
_right = new CastExpr(_right, Type.Real);
}
// Promote result-trees to strings
if (tright instanceof ResultTreeType) {
_right = new CastExpr(_right, Type.String);
}
return _type = Type.Boolean;
}
// In the node-boolean case, convert node to boolean first
if (hasNodeArgs()) {
if (tleft instanceof BooleanType) {
_right = new CastExpr(_right, Type.Boolean);
tright = Type.Boolean;
}
if (tright instanceof BooleanType) {
_left = new CastExpr(_left, Type.Boolean);
tleft = Type.Boolean;
}
}
// Lookup the table of primops to find the best match
MethodType ptype = lookupPrimop(stable, Operators.getOpNames(_op),
new MethodType(Type.Void, tleft, tright));
if (ptype != null) {
Type arg1 = (Type) ptype.argsType().elementAt(0);
if (!arg1.identicalTo(tleft)) {
_left = new CastExpr(_left, arg1);
}
Type arg2 = (Type) ptype.argsType().elementAt(1);
if (!arg2.identicalTo(tright)) {
_right = new CastExpr(_right, arg1);
}
return _type = ptype.resultType();
}
throw new TypeCheckError(this);