Re: [Haskell-beginners] Beginners Digest, Vol 56, Issue 20

Good morning,
I've actually have 6 books in my library. They are:
1. "Algebra Third Edition" by MacLane and Birkhoff
[I couldn't get anything out of this book]
2. "Categories for the Working Mathemetician - Second Edition" by Mac Lane
[I could get through the first chapter and then gave up]
3. "Conceptual Mathematics - A first introduction to categories" by Lawvere
and Schanuel
[The first chapter was understandable but the following chapters were
completely undecipherable]
4. " Basic Category Theory for Computer Scientists" by Pierce
[I could get through all three chapters but couldn't do the exercies -
and could not see how CT applies to Haskell {especially, Monoids, Monads and
Functors}]
5. "Categories and Computer Science" by Walters
[This one made me cry]
6. "Category Theory" by Awodey
[Again, I could only get through the first chapter]
I tried viewing the videos by Eugenia Cheng - but I just couldn't follow her
presentation.
I also viewed another video entitled Hasket and CT - but it was given by a
mathematican and I couldn't follow this fellow - I'll have to get the link
for this.
I finally viewed a video by Brian Beckman in regard to FP [eg: F# and
Haskell - and mentions C# as a comparison non-FP language], specifically, in
regard to Monoids and it was great - however, he didn't go into CT - but he
did recommend that the viewer pursue it.
I'm really not interested in all of the categories in the world...I
specifically am interested in how CT applies to Hask, Monoids, Monads and
Functors.
All of the Haskell authors that I've read have 'ducked' the CT issue -
mentioning that it is not necessary to understand Haskell. I often was left
with the thought: are they correct or do they simply not understand CT.
If you know of a Computer Scientist [and, please, not a Mathematician] who
has written in regard to Haskell and CT, please let me know.
Hopefully, there is a reference that is available that will help me - if
not, I plan on revisting my Haskell books ["Learn You a Haskell for Great
Good!..." by Lipovaca and "Real World Haskell" by O'Sullivan, etal] and
focus in on Functors, Monoids, Monads and Hask. I'll also view Brian
Beckman's video again and see if I can really follow his example.
Thank you
----- Original Message -----
From:
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Today's Topics:
1. Re: Haskell and Category Theory (Rustom Mody) 2. Re: Haskell and Category Theory (Joe Fredette) 3. Re: Effective use of nested Monads (David Hinkes)
----------------------------------------------------------------------
Message: 1 Date: Mon, 11 Feb 2013 19:01:51 +0530 From: Rustom Mody
Subject: Re: [Haskell-beginners] Haskell and Category Theory To: The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell Message-ID: Content-Type: text/plain; charset="iso-8859-1" On Mon, Feb 11, 2013 at 10:37 AM, Brent Yorgey
wrote: On Sun, Feb 10, 2013 at 12:44:11PM -0500, Patrick Lynch wrote:
Good morning, I've tried to read 5 books on Category Theory and finally have admitted defeat. What I'm looking for is simply a book that is geared to Haskell and Category that can be understood by mere mortals. I was trained as an Electrical Engineer, so my math is quite good, but I just don't get Category Theory from these books. If anyone can recomment a book on Category Theory and Haskell, written by a Computer Scientest [no more Mathematicians for me], I welcome it. Thanks, Patrick
Can you tell us which books you've tried to read?
-Brent
Well Brent is not going to say it I guess so someone needs to: Typeclassopedia http://www.haskell.org/haskellwiki/Typeclassopedia is required reading

On Tue, Feb 12, 2013 at 8:32 PM, Patrick Lynch
Good morning,
I've actually have 6 books in my library. They are: 1. "Algebra Third Edition" by MacLane and Birkhoff [I couldn't get anything out of this book] 2. "Categories for the Working Mathemetician - Second Edition" by Mac Lane [I could get through the first chapter and then gave up] 3. "Conceptual Mathematics - A first introduction to categories" by Lawvere and Schanuel [The first chapter was understandable but the following chapters were completely undecipherable] 4. " Basic Category Theory for Computer Scientists" by Pierce [I could get through all three chapters but couldn't do the exercies - and could not see how CT applies to Haskell {especially, Monoids, Monads and Functors}] 5. "Categories and Computer Science" by Walters [This one made me cry] 6. "Category Theory" by Awodey [Again, I could only get through the first chapter]
I tried viewing the videos by Eugenia Cheng - but I just couldn't follow her presentation. I also viewed another video entitled Hasket and CT - but it was given by a mathematican and I couldn't follow this fellow - I'll have to get the link for this. I finally viewed a video by Brian Beckman in regard to FP [eg: F# and Haskell - and mentions C# as a comparison non-FP language], specifically, in regard to Monoids and it was great - however, he didn't go into CT - but he did recommend that the viewer pursue it.
I'm really not interested in all of the categories in the world...I specifically am interested in how CT applies to Hask, Monoids, Monads and Functors. All of the Haskell authors that I've read have 'ducked' the CT issue - mentioning that it is not necessary to understand Haskell. I often was left with the thought: are they correct or do they simply not understand CT. If you know of a Computer Scientist [and, please, not a Mathematician] who has written in regard to Haskell and CT, please let me know.
Not an exact answer... still here are a couple http://www.cs.man.ac.uk/~david/categories/index.html http://arxiv.org/abs/1102.1313 Also Sannella and Tarlecki's http://books.google.co.in/books/about/Foundations_of_Algebraic_Specification_a.html?id=85CLRvu5QxUC&redir_esc=y I cannot say I recommend any very strongly. Sannella and Tarlecki seems to be good but Ive yet to study it The first 50 or so pages of this http://link.springer.com/book/10.1007/3-540-17162-2//page/1 was useful to me. I have no access to it now Rusi -- http://www.the-magus.in http://blog.languager.org

Hi Patrick, I would highly recommend Jeremy Gibbons, "Calculating Functional Programs". In Roland Backhouse‚ Roy Crole and Jeremy Gibbons, editors, Algebraic and Coalgebraic Methods in the Mathematics of Program Construction. Vol. 2297 of Lecture Notes in Computer Science. Pages 148–203. Springer−Verlag. 2002. http://www.cs.ox.ac.uk/publications/publication2360-abstract.html
From what you've said it sounds like this is exactly what you're looking for.
-Brent On Tue, Feb 12, 2013 at 10:02:14AM -0500, Patrick Lynch wrote:
Good morning,
I've actually have 6 books in my library. They are: 1. "Algebra Third Edition" by MacLane and Birkhoff [I couldn't get anything out of this book] 2. "Categories for the Working Mathemetician - Second Edition" by Mac Lane [I could get through the first chapter and then gave up] 3. "Conceptual Mathematics - A first introduction to categories" by Lawvere and Schanuel [The first chapter was understandable but the following chapters were completely undecipherable] 4. " Basic Category Theory for Computer Scientists" by Pierce [I could get through all three chapters but couldn't do the exercies - and could not see how CT applies to Haskell {especially, Monoids, Monads and Functors}] 5. "Categories and Computer Science" by Walters [This one made me cry] 6. "Category Theory" by Awodey [Again, I could only get through the first chapter]
I tried viewing the videos by Eugenia Cheng - but I just couldn't follow her presentation. I also viewed another video entitled Hasket and CT - but it was given by a mathematican and I couldn't follow this fellow - I'll have to get the link for this. I finally viewed a video by Brian Beckman in regard to FP [eg: F# and Haskell - and mentions C# as a comparison non-FP language], specifically, in regard to Monoids and it was great - however, he didn't go into CT - but he did recommend that the viewer pursue it.
I'm really not interested in all of the categories in the world...I specifically am interested in how CT applies to Hask, Monoids, Monads and Functors. All of the Haskell authors that I've read have 'ducked' the CT issue - mentioning that it is not necessary to understand Haskell. I often was left with the thought: are they correct or do they simply not understand CT. If you know of a Computer Scientist [and, please, not a Mathematician] who has written in regard to Haskell and CT, please let me know.
Hopefully, there is a reference that is available that will help me - if not, I plan on revisting my Haskell books ["Learn You a Haskell for Great Good!..." by Lipovaca and "Real World Haskell" by O'Sullivan, etal] and focus in on Functors, Monoids, Monads and Hask. I'll also view Brian Beckman's video again and see if I can really follow his example.
Thank you
----- Original Message ----- From:
To: Sent: Tuesday, February 12, 2013 6:00 AM Subject: Beginners Digest, Vol 56, Issue 20 Send Beginners mailing list submissions to beginners@haskell.org
To subscribe or unsubscribe via the World Wide Web, visit http://www.haskell.org/mailman/listinfo/beginners or, via email, send a message with subject or body 'help' to beginners-request@haskell.org
You can reach the person managing the list at beginners-owner@haskell.org
When replying, please edit your Subject line so it is more specific than "Re: Contents of Beginners digest..."
Today's Topics:
1. Re: Haskell and Category Theory (Rustom Mody) 2. Re: Haskell and Category Theory (Joe Fredette) 3. Re: Effective use of nested Monads (David Hinkes)
----------------------------------------------------------------------
Message: 1 Date: Mon, 11 Feb 2013 19:01:51 +0530 From: Rustom Mody
Subject: Re: [Haskell-beginners] Haskell and Category Theory To: The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell Message-ID: Content-Type: text/plain; charset="iso-8859-1" On Mon, Feb 11, 2013 at 10:37 AM, Brent Yorgey
wrote: On Sun, Feb 10, 2013 at 12:44:11PM -0500, Patrick Lynch wrote:
Good morning, I've tried to read 5 books on Category Theory and finally have admitted defeat. What I'm looking for is simply a book that is geared to Haskell and Category that can be understood by mere mortals. I was trained as an Electrical Engineer, so my math is quite good, but > I just don't get Category Theory from these books. If anyone can recomment a book on Category Theory and Haskell, written by a Computer Scientest [no more Mathematicians for me], I welcome it. Thanks, Patrick
Can you tell us which books you've tried to read?
-Brent
Well Brent is not going to say it I guess so someone needs to: Typeclassopedia http://www.haskell.org/haskellwiki/Typeclassopedia is required reading

On 02/12/2013 02:14 PM, Brent Yorgey wrote:
Hi Patrick,
I would highly recommend
Jeremy Gibbons, "Calculating Functional Programs".
It looks to be available from the author's site: http://www.cs.ox.ac.uk/jeremy.gibbons/publications/acmmpc-calcfp.pdf
participants (4)
-
Brent Yorgey
-
Michael Orlitzky
-
Patrick Lynch
-
Rustom Mody