map-if ( ... seq if-quot: ( ... elt -- ... ? ) map-quot: ( ... elt -- ... newelt ) -- ... newseq )

Vocabulary

sequences.extras

Inputs

seq	a sequence
if-quot	an object
map-quot	an object

Outputs

newseq

a sequence

Word description

A version of map where map-quot is applied only if if-quot returns true for a given element.

Definition

USING: kernel sequences ;

IN: sequences.extras

: map-if
    ( ... seq if-quot: ( ... elt -- ... ? ) map-quot: ( ... elt -- ... newelt ) -- ... newseq )
    [ [ [ dup ] ] dip compose ] dip [ when ] curry compose map ;
    inline