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.
http://www.cs.nott.ac.uk/~nhn/TFP2006/Papers/03-JansenKoopmanPlasmeijer-EfficientInterpretation.pdf Is that the kind of concept you mean? I found this paper quite accessible, so it might be of interest to you. Thanks Neil _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
