interleaved-as ( seq glue exemplar -- newseq )

Vocabulary

sequences.extras

Inputs

seq	a sequence
glue	an object
exemplar	an object

Outputs

newseq

a sequence

Word description

Insert glue between every pair of elements in seq. Resulting sequence will be the same class as exemplar.

Definition

USING: kernel math math.order sequences sequences.private ;

IN: sequences.extras

:: interleaved-as ( seq glue exemplar -- newseq )
    seq length dup 1 - + 0 max exemplar new-sequence
    :> newseq seq [ 2 * newseq set-nth-unsafe ] each-index
    seq length 1 -
    [ 2 * 1 + glue swap newseq set-nth-unsafe ] each-integer
    newseq ;