[Haskell-cafe] Call for GUI examples - Functional Reactive Programming

[David Virebayre]

2011/7/8 Heinrich Apfelmus <apfelmus at quantentunnel.de>:

> I want to hear!
> Just a description. :) You can also mention why you find it interesting etc.

Well I have an old program sitting around. Anyway, it's very simple :

The GUI has
- a window with a menu bar, 2 directory selects (source and dest
directories), 1 file select ( the 'patch file'), 1 textview to write
logging information, and a 'Convert' button to start.
- an about window that opens from a 'About...' menuitem
- A status bar.

The convert button stats an action that scans all applicable files in
a source directory, converts them and writes them in a destination
directory.

The conversion itself is irrelevant to the topic, in my case it
consists in searching for patterns in the file and replacing them,
according to a list of changes read from a file, the 'patch file'.

The progression is logged in the textview: file processed, strings
replaced. In the status bar, a percentage bar grows.



Why do I find it interesting ?

Most of the time I would do a program like the above with a command
line interface only. GUI programming can be tedious. Would FRP offer a
way to code such a simple, boring example in a fun way ?

Also, FRP is often concerned with animations, but I'd really like to
see if it works well for small utilities.

I have an old source code I can share, using gtk2hs, imperative style
(and also beginner-ugly style :) ). It's about 200 lines of codes and
a glade file. It just compiled and ran fine here.