chain<-map

chain <-map: function -> chain

Executes obtainer or block for each element of the chain. Returns a new chain holding the resulting values of executing the code. All elements for which the execution fails are omitted. Argument forwarding:

@arg1 Element tested

@arg2 1-based index of the element

The example below returns a chain with names holding the names of all graphical objects on the graphical device.

graphical_names(Device, Names)  :-
        get(Device, graphicals, Chain),
        get(Chain, map, @arg1?name, Names).

@arg1	Element tested
@arg2	1-based index of the element