heading-segment ( segments current-segment heading -- segment )


Vocabulary
jamshred.tunnel

Inputs
segmentsan object
current-segmentan object
headingan object


Outputs
segmentan object


Definition
USING: accessors combinators kernel math.order math.vectors ;

IN: jamshred.tunnel

: heading-segment
( segments current-segment heading -- segment )
over forward>> vdot 0 <=> {
{ +gt+ [ next-segment ] }
{ +lt+ [ previous-segment ] }
{ +eq+ [ nip ] }
} case ;