Re: [Aldor-l] [Axiom-developer] spad: language and compiler

[Jacques Carette]

Ralf Hemmecke wrote:
> Compile time evaluation in full 
> generality introduces a way make it really hard to find bugs.
>
> But anyway, maybe Aldor should allow compile time evaluation.
>   
Quick remark --  it has been shown that:
1) C++'s template language is a Turing Complete PL
2) Haskell's class types (with common extensions) is also a Turing 
Complete PL
3) All meta-programming systems allow arbitrary compile time evaluation

Yes, it does make debugging harder.  But the advantages seem to _far_ 
outweigh the problems.  One just develops new debugging (and coding) 
techniques to deal with the added power/complexity.

I could re-use Stephen's brilliant closing line from yesterday's email:
   "These kinds of errors have to be seen as bugs in programs, just as 
division by zero is a programming error and not an invalidation of 
integer arithmetic." -- S.M. Watt
[where 'These kinds of errors' is now /Programs with infinite loops in 
types/]

Jacques