Esempio n. 1
0
/*
Retrieve the set for annotated values. If the attachment type
is not a set, then throw an invalid distinct set error and
return.
*/
func getSet(item value.Value) (*value.Set, error) {
	switch item := item.(type) {
	case value.AnnotatedValue:
		ps := item.GetAttachment("set")
		switch ps := ps.(type) {
		case *value.Set:
			return ps, nil
		default:
			return nil, fmt.Errorf("Invalid DISTINCT set %v of type %T.", ps, ps)
		}
	default:
		return nil, fmt.Errorf("Invalid DISTINCT %v of type %T.", item, item)
	}
}
Esempio n. 2
0
/*
Directly call the evaluate method for aggregate functions and
passe in the receiver, current item and current context, for
count with an input expression operand. For a count with no
operands (count (*)), get the count from the attachment and
then evaluate.
*/
func (this *Count) Evaluate(item value.Value, context expression.Context) (result value.Value, e error) {
	if this.Operand() != nil {
		return this.evaluate(this, item, context)
	}

	// Full keyspace count is short-circuited
	switch item := item.(type) {
	case value.AnnotatedValue:
		count := item.GetAttachment("count")
		if count != nil {
			return value.NewValue(count), nil
		}
	}

	return this.evaluate(this, item, context)
}