pluck-at ( key assoc -- assoc' )

Vocabulary

persistent.assocs

Inputs

key	an object
assoc	an object

Outputs

assoc'

an object

Definition

IN: persistent.assocs

GENERIC: pluck-at ( key assoc -- assoc' )

Methods

USING: assocs kernel persistent.assocs ;

M: assoc pluck-at clone [ delete-at ] keep ;


USING: accessors combinators kernel math persistent.assocs
persistent.hashtables persistent.hashtables.nodes ;

M: persistent-hash pluck-at
    [ [ dup hashcode >fixnum ] [ root>> ] bi* (pluck-at) ] keep 
    {
        { [ 2dup root>> eq? ] [ nip ] }
        { [ over not ] [ 2drop PH{ } ] }
        [ count>> 1 - persistent-hash boa ]
    } cond ;