NIL operation

NIL

The NIL operation deletes the current shape from the shape tree. It can be used e.g. to create holes in split operations or to terminate recursive rules.

Related

push / popoperation

Examples

Using NIL to create Holes

NIL a 
Lot-->
   extrude(10)
   split(x){ { ~1 : X | ~1 : NIL }* | ~1 : X } }

Using NIL to stop a Recursion

NIL a 
attr ErkerFact = 0.8
attr ErkerDepth = 0.8
attr ErkerStop = 2

Lot-->
   extrude(10)
   X
   comp(f) { all : Erker }

Erker-->
   case(scope.sx > ErkerStop) :
     s('ErkerFact, 'ErkerFact, 0)
     center(xy)
     alignScopeToGeometry(yUp, 0)
     extrude(ErkerDepth)
     X
     comp(f){top : Erker}
   else:
     NIL