Store two ints as an x, y pair, and access them by x value. When a pair is retrieved, it is deleted from the collection.
offer was designed for use with algorithms that transform the pitch of an incoming note stream. By storing the original and transformed note together (the transformed may be sent in the right inlet, immediately followed by the original, or they can be sent as a list) when the pitch of the note-on is changed, the transformed pitch can be retrieved when the note-off is received.
Common Box Attributes
If the number received in the left inlet matches the x value of an x,y pair stored in offer, the corresponding y value is sent out and the stored pair is deleted.