https://www.stackbuilders.com/tutorials/haskell/gui-application/
Tested with:
This tutorial shows how to build a graphical user interface (GUI) application in Haskell using bindings to GTK+. While working on a calculator program we'll cover the following topics:
Once you finish with the tutorial you will have a solid understanding of how to move on, read the documentation of the gtk3 package, and accomplish your tasks.
The tutorial does not assume any knowledge of Haskell except for a very basic understanding of how to work with the IO monad. The GTK+ binding is very straightforward and imperative in its nature. This may be seen as a downside, but I think it also may make things easier for newcomers to Haskell programming with an imperative background.
Before we start with GTK+ bindings, it's reasonable to ask whether there is a better/alternative solution. Indeed, several libraries are available to create GUI in Haskell:
wx — bindings to wxWidgets. A couple of things about this package I find suspicious: 1) it had delays in development when for a couple of years no new version was released, 2) it's still not present on Stackage. A practical conclusion from the point 2 is that it's not very popular nowadays, or at least not many Haskellers start writing any application with it otherwise it would be added already.X11 — direct translation of the C binding to X11 graphics library (quote taken from the package description). “Direct translation” means that you pass around pointers. Yes, in Haskell code. For documentation authors suggest to look here (although Haddocks are not blank either). Last release was in May 2014.hsqml — the Haskell bindings to Qt Quick. Missing from Stackage. Releases seem to happen once a year.fltkhs — the Haskell bindings to the FLTK GUI library. The package seems to be pretty new and I personally don't see any benefit in using it over more mature solutions.As to GTK+, it seems to be:
It's worth mentioning that Haskell has developed much stronger ecosystem with respect to web-development than GUI and desktop development in general. For further reference about the state of standalone GUI applications in Haskell, refer to: