Pgate advances its subpattern whenever key is true. Pgate must be used within an Event pattern. You can either set the key manually, or use Pn.
The source pattern to be filtered.
Repeat the enclosed pattern repeats times.
Pgate will only return the next value in the source pattern if the event that it belongs to has key set to true. Otherwise it will keep returning the same value. This allows for a gated effect on streams.