[Haskell-cafe] Runge-Kutta and architectural style

[Richard O'Keefe]

I was interested to see a Runge-Kutta package
posted to this list recently, particularly as
I have a fairly simple-minded non-adaptive RK
"generator": an AWK script that takes a table
and some optional stuff and spits out C.  The
Haskell package is, of course, a lot prettier
than my AWK program, as well as offering some
adaptive methods, which is important.

We can imagine a spectrum of RK packages:

(1) Higher order function taking some runtime
     parameters.  That's what we got.

(2) The same specialised for a known table at
     compile time.  Doable using the code that
     we were given plus SPECIALIZE pragmas.  I
     don't how well that works across modules.

(3) A generator that writes Haskell source.

(4) Template Haskell.

(5) A generator that generates native code to
     be called through FFI.

The question is, how do you decide what's the
appropriate approach?