On Wed, 3 Feb 1999 14:10:20 +0100, Rudy Velthuis <rve### [at] gmxnet> wrote:
>I have read somewhere, for #while loops, at the #end, the parser must
>re-read the source to find the #while, like old BASIC dialects did. 

Not true, fortunately.  It stores the offset within the file where the 
#while appears and jumps directly to it upon hitting the #end.  

>Perhaps there would be demand for a small program, which unravels #while
>loops and macros and creates (huge) include files out of them, taking a bit
>out of the parsing POV-Ray does. 

Interesting idea, but I'm not sure you'll save much time, as that's 
practically the same as what POV already does.  By seeking backward
in the file, it essentially duplicates the code as many times as 
needed.  The only thing you'd save is a few seeks (nearly instantaneous 
anyway except when it's a macro defined in another file), a few 
expression evaluations (these could potentially be slow, but usually 
aren't), and a few symbol lookups on your index variable (very fast.)  

I do wonder, though, if POV could be coaxed to output a .pov file
in canonical form as it parses a set of .pov and .inc files - with 
commas inserted where necessary and looping and conditionals and 
symbols and includes (all the #-stuff) and comments removed.  I 
think this goes a bit further than you were proposing.  It'd be 
less readable to humans, but it would be oh-so-easy for third-party 
parsers to read, and perhaps slightly faster for POV as well.  Some 
files, like the mandelbrot set made of spheres, would run much more 
quickly.

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