/*
Aggregate input partial values into cumulative result number value
for sum and count. If the partial results are not numbers, then
return an error.
*/
func (this *Avg) cumulatePart(part, cumulative value.Value, context Context) (value.Value, error) {
if part == value.NULL_VALUE {
return cumulative, nil
} else if cumulative == value.NULL_VALUE {
return part, nil
}
psum, _ := part.Field("sum")
pcount, _ := part.Field("count")
csum, _ := cumulative.Field("sum")
ccount, _ := cumulative.Field("count")
if psum.Type() != value.NUMBER || pcount.Type() != value.NUMBER ||
csum.Type() != value.NUMBER || ccount.Type() != value.NUMBER {
return nil, fmt.Errorf("Missing or invalid partial sum or count in AVG: %v, %v, %v, v.",
psum.Actual(), pcount.Actual(), csum.Actual(), ccount.Actual())
}
cumulative.SetField("sum", psum.Actual().(float64)+csum.Actual().(float64))
cumulative.SetField("count", pcount.Actual().(float64)+ccount.Actual().(float64))
return cumulative, nil
}
/*
Call SetField using item value and set the identifier
string to the value. The SetField method returns a
boolean value. If it is nil return true since no error
was encountered while setting the field.
*/
func (this *Identifier) Set(item, val value.Value, context Context) bool {
er := item.SetField(this.identifier, val)
return er == nil
}