On Mon, Jun 29, 2009 at 11:40:28AM -0700, Justin Bailey wrote:
Anyways, for those who care, the heart of my VM implementation was a monadic fold over the program, with a mutable array representing the machine's memory, all inside ''runSTUArray.'' I used a simple data type to represent the machine:
data Machine = Machine { instrs :: [OpCode] , dataMem :: UArray Int Val , outputs :: UArray Int Val , status :: !Int , inputs :: IntMap Val }
where ''dataMem'' holds the data memory area. To execute a program, I folded over the ''instrs'' list and updated memory as I went:
Nice. I did something pretty similar, although I just used association lists for the inputs and outputs---although I bet it would have been faster if I used arrays like you did! I plan to post some thoughts on my blog (syndicated on Planet Haskell) sometime later today or tomorrow. -Brent