find-pred ( ... seq quot: ( ... elt -- ... calc ) pred: ( ... calc -- ... ? ) -- ... calc/f i/f elt/f )

Vocabulary

sequences.extras

Inputs

seq	a sequence
quot	a quotation
pred	a quotation

Outputs

calc/f	an object
i/f	an object
elt/f	an object

Word description

A version of find that saves the calculation done by the first quotation and returns the calulation, element, and index if the calculation matches a predicate quotation.

Examples

USING: math kernel sequences.extras prettyprint ; { 4 5 6 } [ sq ] [ 20 > ] find-pred [ . ] tri@
25 5 1

Definition

USING: kernel sequences sequences.private ;

IN: sequences.extras

: find-pred
    ( ... seq quot: ( ... elt -- ... calc ) pred: ( ... calc -- ... ? ) -- ... calc/f i/f elt/f )
    [ 0 ] 3dip [ [ length check-length ] keep ] 2dip
    [ [ [ nth-unsafe ] ] dip [ 1check ] curry compose ] dip
    [ 1check ] curry compose find-pred-loop swapd ; inline