Re: A couple of questions about goops method parameters

[Panicz Maciej Godek]

2014-09-05 21:12 GMT+02:00 David Thompson <address@hidden>:
> Panicz Maciej Godek <address@hidden> writes:
>>
>> So perhaps you could tell me how to design a GUI framework in FP and
>> without OOP. To me it seems that GUI is the main domain the OOP was
>> crafted for, but if you have some nice functional ideas, perhaps you
>> could help me to redesign my framework.
>>
>
> Are you familiar with functional reactive programming?
>
> http://elm-lang.org/learn/What-is-FRP.elm
>
> Using FRP, we can model with mutable state in a pure, functional way.
> That is, the necessary mutation is hidden behind the runtime of the FRP
> implementation.
>
> Just some food for thought.

Sure, I've been reading a lot, but I didn't manage to get much of it.
I mean, the toy examples are really nice, but it's hard for me to see
the advantage of FRP over OOP in practical systems (e.g. windowed
applications with buttons and so on). Although I see value in
encapsulating state mutations, the notion of state seems inevitable in
describing such applications (like the mere fact that a checkbox can
be checked or not -- so it's a state which is a part of the
description).

BTW I recently ran into a problem with your signal propagation
framework from (guile 2d). Namely, if a signal is itself a mutable
object (like a vector or an array), then changing the value of that
object doesn't propagate (because it happens only when you use
slot-set!, and not (vector-set! (slot-ref ...)...)).
I can't find any workaround for that.