odd-indices ( seq -- seq' )

Vocabulary

sequences.extras

Inputs

seq	a sequence

Outputs

seq'	a sequence

Word description

Push a sequence containing the odd-indexed elements in seq.

Definition

USING: kernel math sequences sequences.private ;

IN: sequences.extras

: odd-indices ( seq -- seq' )
    [ length 2/ ] keep
    [ [ [ 2 * 1 + ] dip nth-unsafe ] curry ] keep
    map-integers-as ;