'Functional vs OO' :coding a GUI

[slenkarParticipant]

OO is nicely suited to making a gui,

for example a button,

A button would inherit the function of knowing when it is clicked from its parent, a generic gui element

then the button has its own ‘clicked’ method which handles what happens when the button is clicked.

You can also extend button , so you can have an ‘up’ button which moves the player up, extended from the ‘button’ class.

How would all of this be done in a functional language?

[papgarParticipant]

Do you mean functional with dynamic code via lambdas or do you mean functional as in calling a function?

[impixiParticipant]

I was going to ask the same question…

Functional: https://en.wikipedia.org/wiki/Functional_programming
Procedural: https://en.wikipedia.org/wiki/Procedural_programming

Functional programming, as in lisp, clojure, etc
Procedural programming, as in old style basic, pascal, c, etc.

There are different GUI implementation strategies for both styles, though IIRC it’s rather difficult to do in a purely functional manner.

[slenkarParticipant]

Functional as in Lisp etc.

It’s getting popular so I’ve always wondered how things are done that way.

[coconParticipant]

There could be lots of projects out there that will give you an idea, for example I will mention this one:
https://github.com/ailisp/simple-gui

[slenkarParticipant]

Thanks.

, it’s not very readable I wonder if it is written like when someone writes in a way that is difficult to read in C.But it’s unnecessary.

[coconParticipant]

Functional programming is a different school of thought. For example in imperative programming languages you would consider an approach like “Firstly_DoThis”, “Secondly_DoThat” and so on, you put each statement after another where they would be executed sequentially. In functional programming languages you would consider doing something like this “GiveMeTheResult(ButFirstCalculateThis(GetSomeDataFromHere(), GetSomeDataFromSomewhereElse())).

The basic idea with this concept is that programs are considered to be consisted out of expressions (as “math expressions”) rather than sequential steps. This is why in lisp you see so many parentheses. In other functional programming languages as in F# or Scala the concept of “piping” have emerged to reduce the amount of parentheses.

[abakoboParticipant]

Search for “functional reactive programming”.

But my opinion on this is that functional is not really relevant for direct I/O stuffs. For the FP lovers only. Nearly all GUI toolkits are imperative.

[coconParticipant]

This is somehow related to the nature of the problem, for example GUIs are based completely on event driven architecture. Another case where FP doesn’t fit is resource management (memory, network, hardware) where simply the paradigm collapses. I remember once doing some OpenGL with F# for fun and the code was totally imperative.

[slenkarParticipant]

Thanks,  I have used Javascript promises, which seem to be the same as the

dothis().thenthis()

example you gave

[Author]

Posts