> Dear Haskell implementors, > > Consider the compilation flag -allow-extension-for-bottom > > which changes the language meaning so that allows to ignore > the bottom value. For example, the programs > > (1) (\ x -> (if p x then foo (g x) else foo (h x)) ) > and > (2) (\ x -> foo ((if p x then g x else h x)) ) > > become equivalent, and many program transformations become > possible.
Is it not the case that with -allow-extension-for-bottom all programs are equivalent to error "Finished" and hence not just 1000 times faster but infinitely faster (asymptotically)? Seriously, I can see that something like this might be of interest, but the details are not trivial. For a start, you'd want to allow refinements only - from _|_ to non-_|_ - rather than in both directions, to disallow the above transformation. But then you'd have to deal with refinement relations rather than equivalences everywhere in the theory, losing symmetry and making things more complicated. --KW 8-) _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
