RE: [colorforth] Machineforth IFs

[Fréderic DUBOIS <frederic.dubois@xxxxxxxxxxxxx>]

Thanks I'll meditate that and the material (BTW what are vectored jumps? -
you mean DEFERs :) for the week-end.

> -----Message d'origine-----
> De : Chuck Moore [mailto:chipchuck@xxxxxxxxxxxxxx]
> Envoyé : ven. 31 janvier 2003 17:38
> À : colorforth@xxxxxxxxxxxxxxxxxx
> Objet : Re: [colorforth] Machineforth IFs
> 
> 
> Machine-Forth  if  is non-destructive for 2 reasons:
>      It seems that only half the  ifs  want to be 
> destructive. ?dup is an
> ugly word.
>      The decoding for the  drop  instruction is already difficult. A
> destructive  if  would make it more so.
> 
> The best strategy for dealing with  if  is to not use it. I 
> think that good
> code has a minimal number of conditionals. Many decisions can 
> be made at
> compile time. The vectored  jump  can replace a decision tree.
> 
> But given that you must sometimes use it, I see no 
> alternative to sprinkling
> drop  around.  On the c18, this often costs neither time nor space,
> depending on instruction packing.
> 
 

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