group-flow ( seq -- newseq )

Vocabulary

prettyprint.sections

Inputs

seq

an object

Outputs

newseq

an object

Definition

USING: kernel make math namespaces sequences splitting ;

IN: prettyprint.sections

: group-flow ( seq -- newseq )
    [
        dup length <iota> [
            2dup 1 - swap ?nth prev set 2dup 1 + swap ?nth
            next set swap nth dup split-before dup , split-after
        ] with each
    ] { } make { t } split harvest ;