--- Tom Pledger <Tom.Pledger@peace.com> wrote:
Nick Name writes: : | Ok I can't resist longer. It's ages I have been wondering what's a | catamorphism, and an anamorphism, and what the hell does it mean | "data is expressed by destructors and not by constructors", but I | have had no time till now. Please some of you all catamorphism | experts tell me a good and clear article to read :)))
As a reader but not an expert, I recommend http://www.cse.ogi.edu/~mpj/pubs/springschool.html
There's also Lex Augusteijn "Sorting Morphisms" (1998) http://citeseer.nj.nec.com/augusteijn98sorting.html http://www.di.uminho.pt/afp98/PAPERS/Lex.ps A useful paper on the various -morphisms in the famous Bananas series of titles: Erik Meijer, Graham Hutton Bananas in Space: Extending Fold and Unfold to Exponential Types (1995) http://citeseer.nj.nec.com/meijer95bananas.html http://www.cs.nott.ac.uk/~gmh/bananas.ps The more abstract, original Bananas paper: Erik Meijer, Maarten Fokkinga, Ross Paterson Functional Programming with Bananas, Lenses, Envelopes and Barbed Wire (1991) http://citeseer.nj.nec.com/meijer91functional.html http://research.microsoft.com/~emeijer/Papers/fpca91.pdf http://wwwhome.cs.utwente.nl/~fokkinga/mmf91m.ps There are other Bananas out there, but some have to do with imports and tariffs... ;-) Chris ===== Christopher Milton cmiltonperl@yahoo.com __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com