2009/6/29 minh thu <noteed@gmail.com>

> First step solved. (BTW: I am attaching the first version to this e-mail. I
> will upload to Hackage upon completion, when getIEEE754float64le and
> putIEEE754float64le functions are done!)

Indeed, I found the binary format a difficulty for haskell. But in
fact, hackage has a module that does the work:
http://hackage.haskell.org/package/data-binary-ieee754

Shame on me! :-(
If only I have posted this rant earlier! :-D

> 2) Running the VM:
>
> This is the step I am working on. A really good and obvious approach to run
> the VM is to use a RWS monad, since:
>
> a) I have a fixed environment (the program and the input ports)
> b) I have a state (the program counter, the status register and the
> data memory contents)
> c) I have a monoid output (the output ports)
>

Why a monad ? Why not just a function State -> State and the use a function like
iterate to do the work ?

I am considering that using the monad all the state and environment threading will be simplified. The output part is optional.

But you are absolutely right, I could use a state composed by (Inputs, program counter, status, data), which would do just as well, as it is just a matter of not touching the program and the input.

> 3) Controlling the sattelites
>
> This is going to be a piece of cake (aheeem! Just kidding!!). After
> computing the VM iteration, another computation will take the output data
> time series and estimate the next move.

The next move is easy to estimate : you have the vm and simulating code at hand.
Of course, making the best move is another problem.

I think the simulator itself is another State->State function, but this time the state is a [Output].

Good luck !

Thanks!