> If we join them then for every call it should be reevaluated. Imagine such
> example:
>
> pigment{
>   function{
>     if(y>0)
>      pattern{object{
>        if(z>0)
>          sphere{0 1
>        else
>          box{-1 1
>        end
>          rotate x* if ( vlength(<x,y,z> > 1 )  30 else (2+x+y+z) end
>        }}}
>     else
>       x+y+z
>    end
>   }
> }

Thanks a lot -- you have given me a perfect illustration why (in a good
language) there must be no such thing as pre-processor. Let's rip short
piece out of it and have a closer look:

object{
   if(z>0)
     sphere{0 1
   else
     box{-1 1
    end
    rotate x* if ( vlength(<x,y,z> > 1 )  30 else (2+x+y+z) end
}

This code fragment is only possible since it is fed to pre-processor, not to
SDL interpreter... Otherwise, you would *have* to write something like this:

#local Rotate = transform { rotate ... }
object { ... Rotate }

(for obvious reasons), that is both more reliable, and... more elegant. A
language with that powerful pre-processor is at risk to quickly become a
"write-only" language, you know... (Perl had succeeded at that w/o
preprocessor at all, but nevertheless... :-)

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