On Tue, Nov 3, 2009 at 2:16 PM, Tracy Wadleigh
I had to implement a ring buffer, and I wanted the code using it to be
written in Haskell. I ended up implementing the buffer in C, and wrapping it in FFI from Haskell because implementing a destructive array in Haskell is kind of unwieldy to someone of my experience level. In Clean, it looks like the uniqueness typing allows for destructive updates in a very controlled manner.
The ST monad provides this functionality. The never-instantiated-in-a-visible-way state parameter of the ST monad provides the "uniqueness" required for doing destructive updates in a pure way.
Someone suggested that to me on IRC once I'd already cranked out a C implementation with FFI bindings. It's just too easy to use the FFI in Haskell :-) If we raise the barrier of FFI, more people will use ST! Dave
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe