On Fri, Jan 16, 2009 at 10:28 PM, Apfelmus, Heinrich
david48 wrote:
I don't care about the name, it's ok for me that the name mathematicians defined is used, but there are about two categories of people using haskell and I would love that each concept would be adequately documented for everyone: - real-world oriented programming documentation with usefulness and examples for the non mathematician - the mathematics concepts and research papers for the mathematicians for those who want/need to go further
As someone mentionned, the documentation can't really be done by someone that doesn't fully grok the concepts involved.
Good account of the current documentation situation.
Hm, what about the option of opening Bird's "Introduction on Functional Programming using Haskell" in the section about fold? Monoid is on page 62 in the translated copy I've got here.
I don't have this book. I have real world haskell and purely functional data structures though.
Does Hutton's book mention them? Real World Haskell?
the first time it is mentionned in RWH according to the index is page 266 where we read "We forgot to test the Monoid instance" ... "...of Monoid, which is the class of types that support appending and empty elements:" Appending.... :) On the other hand, on page 320 there is a nice explanation of Monoid, and on page 380, which isn't mentionned in the index, there might be the first time one can understand why the writer monad works with monoids instead of lists: to be able to use better suited data types for appending. All of this is still lacking the great why : why/how an abstraction so generic can be useful. I'm starting to believe that the only reason to make a datatype an instance of Monoid is... why not ! since it's not hard to find an associative operation and a neutral element.
I don't think that I would try to learn a programming language, for example Python, without obtaining a paper book on it.
I would, if the online documentation makes it possible, and then I would buy a paper book later, to go further or for reference. That's how I learned Haskell, and much later I've bought my first book.