pop-front ( deque -- item newdeque )
Persistent deques

Prev:push-back ( deque item -- newdeque )
Next:pop-back ( deque -- item newdeque )


Vocabulary
persistent.deques

Inputs
dequean object


Outputs
iteman object
newdequea deque


Word description
Creates a new deque with the frontmost item removed. This takes amortized constant time with single-threaded access.

Definition