[Also on
http://www.joachim-breitner.de/blog/archives/229-A-different-Maybe-maybe.html]
Hi,
For a while I have been thinking: Isn’t there a way to get rid of the
intermediate Maybe construct in a common expression like “fromMaybe
default . lookup”. It seems that a way to do that would be to pass more
information to the Maybe-generating function: What to do with a
Just-Value, and what to return in case of Nothing. This leads to a new
definion of the Maybe data type as a function. Later I discovered that
this seems to work for any algebraic data type.
This is probably nothing new, but was offline at the time of writing, so
I didn’t check. This means that this might also be total rubbish. Enjoy.
* “Algebraic Data Type Done Differently” (PDF-File) at
http://www.joachim-breitner.de/various/FunctionalMaybe.pdf
* “Algebraic Data Type Done Differently” (Literate Haskell Source)
at http://www.joachim-breitner.de/various/FunctionalMaybe.lhs
Comments are appreciated.
Greetings from my holidays,
Joachim
--
Joachim "nomeata" Breitner
mail: [EMAIL PROTECTED] | ICQ# 74513189 | GPG-Key: 4743206C
JID: [EMAIL PROTECTED] | http://www.joachim-breitner.de/
Debian Developer: [EMAIL PROTECTED]
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
