# completing Wrap a 2-arg function as a `%Reducer`. Optional 2nd arg supplies a custom completing fn. ## Syntax

[completing $f]
[completing $f $cf]

## Parameters - `$f` — Binary reducing function. - `$cf` — (optional) Completing function called once on the final result. ## Examples

[transduce [map { ($it * 2) }] [completing +] 0 @{ 1 2 3}]

## Returns A `%Reducer{:init nil :step $f :done $cf}` (or identity when `$cf` omitted). ## See Also `transduce`, `into`, `reduced`, `comp`