On Thu, Oct 2, 2008 at 4:11 AM, Bulat Ziganshin <[EMAIL PROTECTED]> wrote: > finally, ghc now includes some form of active patterns which may be > used to define your own way to decompose values. but their syntax > isn't compatible with constructors so you can't define complex type > which mimicks simple ones, and in particular you can replace simple > type with complex one w/o rewriting all the client code > > imho it's serious lack in haskell support for Abstract Data Types
Not that this hasn't probably been discussed at length elsewhere, I wholeheartedly agree. The ability to mimic a simple type with a complex one is precisely what moves views from "syntax sugar", which does little more than to make code easier on the eyes, into a proper abstraction mechanism that actually adds engineering value. Luke _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
