skaller wrote:

>What about high level optimisations?
>
>Felix supports this:
>
>	reduce revrev[t] (x:list[t]): rev (rev x) => x;
>
>which, combined with inlining, removes adjacent list reversals.
>This is a fairly trivial example of integrating logic with
>programming as a way of achieving both correctness and
>performance: the reduction above provides both semantic
>knowledge to the reader as well as allowing the compiler
>to generate better code.
>  
>

Haskell (GHC to be precise) allows that too. But is syntactic 
term-rewriting, in other words it is *untyped*.

Ocaml is great because it is statically typed.  MetaOCaml is wonderful 
because it is statically typed.  Adding an untyped layer to a typed 
language seems like a definite step backwards (i.e. a hack).. 

Jacques