Re: The state of functional programming

[Georg Bauhaus <rm-host.bauhaus@maps.futureapps.de>]

On 7/29/10 11:01 PM, Warren wrote:

> Again, in Ada you "declare" the "how". In FP, you "declare"
> the "problem" to be solved.

> Anyway, I'm done here.  I'm starting to feel like
> a parrot.

I guess, then, you will ignore my chatter through the cage's wires. ;)

Is there anything non-FP in

let input = float_of_string Sys.argv.(1) in
  let output = print_float in
   let square x = x *. x in
    output (square input) ;;


I really don't know how it is possible to "declare" the "problem" in FP
without thinking about "how" some functions establish the "what" of the
solution. Even in Prolog.
To me FP always boils down to assembling a solution from "more primitive"
functions. These are ultimately composed of initial functions.

The process of arranging functions properly will establish the "how" part
of FP.  I *have* to write the proper equations, choosing the correct
functions; I *have* to write expressions involving the correct
functions. These are not pre-solved.  I do *not*  in general instruct
an Ada compiler how to chose a sequence of processor instructions
for my Ada program.

The only difference I see is that in true FP there is no explicit
state manipulation.  Has there been a true FPL other than inference
engines before the point when Haskell introduced monads?


Georg