progressive-index-by-as ( seq1 seq2 quot exemplar -- hash seq )

Vocabulary

sequences.extras

Inputs

seq1	an object
seq2	an object
quot	an object
exemplar	an object

Outputs

hash	an object
seq	an object

Definition

USING: kernel sequences ;

IN: sequences.extras

: progressive-index-by-as
    ( seq1 seq2 quot exemplar -- hash seq )
    [
        pick length '[
            tuck [ @ over inc-at* drop ] 2dip swap nth-index
            _ or
        ] [ H{ } clone ] 3dip with
    ] dip map-as ; inline