John Meacham wrote:
ghc's strictness analyzer is pretty darn good, If something is subtle enough for the compiler not to catch it, then the programmer probably won't right off the bat either.
Even the best strictness analyzer can't determine that a function is strict when it really isn't. The main point of strictness annotations, I think, is to actually change the denotational semantics of the program.
strictness does not belong in the type system in general. strictness annotations are attached to the data components and not type components in data declarations because they only affect the desugaring of the constructor, but not the run-time representation or the types in general. attaching strictness info to types is just the wrong thing to do in general I think.
Your argument seems circular. Haskell 98 strictness annotations are just sugar, but they didn't *have* to be. You can say that f is strict if f _|_ = _|_, or you can say it's strict if its domain doesn't include _|_ at all. One feels more at home in the value language (seq, ! on constructor fields), the other feels more at home in the type language (! on the left of the function arrow, more generally ! on types to mean lack of _|_).
-- Ben _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://haskell.org/mailman/listinfo/haskell-prime
