delete-node-if* ( ... dlist quot: ( ... value -- ... ? ) -- ... obj/f ? )
Factor handbook » The language » Collections » Double-linked lists

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Vocabulary
dlists

Inputs

dlist	dlist
quot	a quotation

Outputs

obj/f	an object or f
?	a boolean

Word description
Calls dlist-find on the dlist and deletes the node returned, if any. Returns the value of the deleted node and a boolean to allow the deleted value to distinguished from f, for nothing deleted.

Notes
This operation is O(n).

Definition

USING: accessors deques kernel ;

IN: dlists

: delete-node-if*
    ( ... dlist quot: ( ... value -- ... ? ) -- ... obj/f ? )
    dupd dlist-find-node [
        dup
        [ [ swap delete-node ] keep obj>> t ] [ 2drop f f ] if
    ] [ drop f f ] if* ; inline