[Haskell-cafe] Is it usual to read a Maybe (IORef a) ?

Johannes Waldmann waldmann at imn.htwk-leipzig.de
Thu Sep 4 02:36:46 EDT 2008


Timothy Goddard wrote:
> It looks like this code isn't really in fitting with normal Haskell idioms [...]

this is all very much true.

Still I understand the application area (for this example)
is interactive graph editing
and there the "in-place update" perhaps is the right model
for what the user of the program does (remove/insert node/edge).

So at least the model of the GUI needs some notion of "state"?
Of course from the GUI state one should compute the underlying
and *immutable* data object for further processing.

J.W.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 257 bytes
Desc: OpenPGP digital signature
Url : http://www.haskell.org/pipermail/haskell-cafe/attachments/20080904/5727085e/signature.bin


More information about the Haskell-Cafe mailing list