equals
equals compares the input context to the operand and returns either the input context unchanged, if it is the same as the operand, or an empty set if it is not.
| Context | Type |
|---|---|
| Input | any set or collection |
| Output | either the same as the input or an empty set |
If the operand is equal to the input context, then the output is the same context. If the operand is not equal to the input context, then the output is an empty set.
| Parameter | Type |
|---|---|
| operand | a set or collection of the same type as the input |
Examples
Finds all aircraft if the aircraft are exactly the objects piloted. If they are different, then the output will be an empty set:
objects(type="airplane").equals(objects(pilots > 0))