3.5 Collection actions

A collection as a whole can be manipulated by a collection action. Elements in the collection are ordered or unordered. The action applies a subaction on one element at each time. The collection is given to the collection action from an input pin, and the result is produced and put on an output pin.

Some of the collection actions described below require the collection to be ordered, while others do not.

A collection action may also take multiple collections as input. In this case, the parameter to the subaction is a tuple with multiple elements, each of which is taken from a different collection. The collections must be ordered and have the same cardinality to have their elements matched in a unique way.

It is also possible that, apart from the collections, the action has more input pins which take single values. Those values are passed to the subaction in each execution. They are considered as constants, and will not be put on the output pins.