LYAHFGG, chapter 11 question

About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I *taught* My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents? Sincerely, Frank D. Martinez -- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6

You are nearing the end of the book, and it is pulling out some more
advanced concepts on you. I didn't understand applicatives until a bit
later, and you certainly don't need to understand them to code reasonable
haskell. Nonetheless, they exist and are used quite a bit and so it is
worthwhile to present them.
It may help you to pull out ghci and start messing with bits of code as you
read so that you can get a feel for it intuitively.
On Tue, Aug 26, 2014 at 10:33 PM, Frank
About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I *taught* My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents?
Sincerely, Frank D. Martinez
-- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

I had originally encountered problems at this point myself. I lost motivation because I had just had this feeling that programming with applicatives was just not going to be fun, and it was beginning to seem like Haskell programming might involve a lot of this. I put the book down for about 1 year. Somewhere I came across an article on Monads that changed my mind. I started over and am now almost done with Chapter 13. This time around things are looking a lot cooler. I think chapters 11,12, and 13 may lack the motivational information to keep one going. I can say that the author Miran Lipovaca really does a great job of explaining this material. I don't think you are going to find a better source. Absolutely every step of the way is laid out in painstaking detail. Plus there are constant reminders of material that was just covered that is relevant to the immediate situation. All I can say is go slow and make sure you understand every detail before proceeding. Keep at it regularly so as not to forget important terms. Go back and reread if necessary. Have the confidence that it will be worthwhile. The Monad chapters are little bit more interesting, but you will need to understand the applicatives first. I learned a new word today, "Sisyphean." From: Beginners [mailto:beginners-bounces@haskell.org] On Behalf Of Frank Sent: Tuesday, August 26, 2014 7:33 PM To: The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell Subject: [Haskell-beginners] LYAHFGG, chapter 11 question About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I taught My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents? Sincerely, Frank D. Martinez -- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6

My own experience with Learn You a Haskell was different from Jeff's. I
found the stuff on applicatives difficult, and couldn't see their point
much, so I just kept going with the book without bothering to understand
them fully. Monads I found a lot easier to understand and much easier to
see their point. I don't think you need to understand applicatives before
you understand monads; in fact, I think it's easier the other way round.
And monads seem to be used much more often than applicatives in Haskell. I
eventually got back to applicatives when I was mucking around with Parsec.
In the context of parsing, it was a lot easier to understand how they work
and why they're useful.
On Wed, Aug 27, 2014 at 10:21 AM, Jeff C. Britton
I had originally encountered problems at this point myself. I lost motivation because I had just had this feeling that programming with applicatives was just not going to be fun, and it was beginning to seem like Haskell programming might involve a lot of this. I put the book down for about 1 year. Somewhere I came across an article on Monads that changed my mind. I started over and am now almost done with Chapter 13. This time around things are looking a lot cooler. I think chapters 11,12, and 13 may lack the motivational information to keep one going. I can say that the author Miran Lipovaca really does a great job of explaining this material. I don't think you are going to find a better source. Absolutely every step of the way is laid out in painstaking detail. Plus there are constant reminders of material that was just covered that is relevant to the immediate situation. All I can say is go slow and make sure you understand every detail before proceeding. Keep at it regularly so as not to forget important terms. Go back and reread if necessary. Have the confidence that it will be worthwhile. The Monad chapters are little bit more interesting, but you will need to understand the applicatives first. I learned a new word today, "Sisyphean."
*From:* Beginners [mailto:beginners-bounces@haskell.org] *On Behalf Of * Frank *Sent:* Tuesday, August 26, 2014 7:33 PM *To:* The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell *Subject:* [Haskell-beginners] LYAHFGG, chapter 11 question
About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I *taught* My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents?
Sincerely,
Frank D. Martinez
-- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

On Tue, Aug 26, 2014 at 11:32 PM, Matthew Moppett
And monads seem to be used much more often than applicatives in Haskell.
Much of that is historical: Monads have been around for a long time, Applicatives are fairly recent, and a lot of things that are best done with Applicatives were done with Monads because they were there. -- brandon s allbery kf8nh sine nomine associates allbery.b@gmail.com ballbery@sinenomine.net unix, openafs, kerberos, infrastructure, xmonad http://sinenomine.net

I learned a new word today, “Sisyphean.”
Me too! :)
Peter
On 27 August 2014 04:21, Jeff C. Britton
I had originally encountered problems at this point myself. I lost motivation because I had just had this feeling that programming with applicatives was just not going to be fun, and it was beginning to seem like Haskell programming might involve a lot of this. I put the book down for about 1 year. Somewhere I came across an article on Monads that changed my mind. I started over and am now almost done with Chapter 13. This time around things are looking a lot cooler. I think chapters 11,12, and 13 may lack the motivational information to keep one going. I can say that the author Miran Lipovaca really does a great job of explaining this material. I don’t think you are going to find a better source. Absolutely every step of the way is laid out in painstaking detail. Plus there are constant reminders of material that was just covered that is relevant to the immediate situation. All I can say is go slow and make sure you understand every detail before proceeding. Keep at it regularly so as not to forget important terms. Go back and reread if necessary. Have the confidence that it will be worthwhile. The Monad chapters are little bit more interesting, but you will need to understand the applicatives first. I learned a new word today, “Sisyphean.”
*From:* Beginners [mailto:beginners-bounces@haskell.org] *On Behalf Of * Frank *Sent:* Tuesday, August 26, 2014 7:33 PM *To:* The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell *Subject:* [Haskell-beginners] LYAHFGG, chapter 11 question
About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I *taught* My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents?
Sincerely,
Frank D. Martinez
-- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Actually, I remember that that chapter being difficult too, so much so that
I don't think I finished it. It might be worth coming back to that chapter
later, after you have more practical experience.
In the mean time though, if I could tell you only one fact about how to use
Applicative, it would be this.
Say you have some pure function:
f :: Int -> Int -> Int -> Int
And some values that may or may not be in the context of some Applicative
functor (let's say Maybe)
x :: Maybe Int
y :: Int
z :: Maybe Int
Then you can call f like this:
(f <$> x <*> pure y <*> z ) :: Maybe Int
So if you were in the middle of some do notation you could
do
myF <- f <$> x <*> pure y <*> z
...
rather than the more painful
do
x' <- x
z' <- z
let myF = f x' y z'
...
On Wed, Aug 27, 2014 at 10:22 AM, Peter Hall
I learned a new word today, “Sisyphean.”
Me too! :)
Peter
On 27 August 2014 04:21, Jeff C. Britton
wrote: I had originally encountered problems at this point myself. I lost motivation because I had just had this feeling that programming with applicatives was just not going to be fun, and it was beginning to seem like Haskell programming might involve a lot of this. I put the book down for about 1 year. Somewhere I came across an article on Monads that changed my mind. I started over and am now almost done with Chapter 13. This time around things are looking a lot cooler. I think chapters 11,12, and 13 may lack the motivational information to keep one going. I can say that the author Miran Lipovaca really does a great job of explaining this material. I don’t think you are going to find a better source. Absolutely every step of the way is laid out in painstaking detail. Plus there are constant reminders of material that was just covered that is relevant to the immediate situation. All I can say is go slow and make sure you understand every detail before proceeding. Keep at it regularly so as not to forget important terms. Go back and reread if necessary. Have the confidence that it will be worthwhile. The Monad chapters are little bit more interesting, but you will need to understand the applicatives first. I learned a new word today, “Sisyphean.”
*From:* Beginners [mailto:beginners-bounces@haskell.org] *On Behalf Of * Frank *Sent:* Tuesday, August 26, 2014 7:33 PM *To:* The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell *Subject:* [Haskell-beginners] LYAHFGG, chapter 11 question
About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I *taught* My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents?
Sincerely,
Frank D. Martinez
-- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Actually, I remember that that chapter being difficult too, so much so that
I don't think I finished it. It might be worth coming back to that chapter
later, after you have more practical experience.
In the mean time though, if I could tell you only one fact about how to use
Applicative, it would be this.
Say you have some pure function:
f :: Int -> Int -> Int -> Int
And some values that may or may not be in the context of some Applicative
functor (let's say Maybe)
x :: Maybe Int
y :: Int
z :: Maybe Int
Then you can call f like this:
(f <$> x <*> pure y <*> z ) :: Maybe Int
So if you were in the middle of some do notation you could
do
myF <- f <$> x <*> pure y <*> z
...
rather than the more painful
do
x' <- x
z' <- z
let myF = f x' y z'
...
On Wed, Aug 27, 2014 at 10:22 AM, Peter Hall
I learned a new word today, “Sisyphean.”
Me too! :)
Peter
On 27 August 2014 04:21, Jeff C. Britton
wrote: I had originally encountered problems at this point myself. I lost motivation because I had just had this feeling that programming with applicatives was just not going to be fun, and it was beginning to seem like Haskell programming might involve a lot of this. I put the book down for about 1 year. Somewhere I came across an article on Monads that changed my mind. I started over and am now almost done with Chapter 13. This time around things are looking a lot cooler. I think chapters 11,12, and 13 may lack the motivational information to keep one going. I can say that the author Miran Lipovaca really does a great job of explaining this material. I don’t think you are going to find a better source. Absolutely every step of the way is laid out in painstaking detail. Plus there are constant reminders of material that was just covered that is relevant to the immediate situation. All I can say is go slow and make sure you understand every detail before proceeding. Keep at it regularly so as not to forget important terms. Go back and reread if necessary. Have the confidence that it will be worthwhile. The Monad chapters are little bit more interesting, but you will need to understand the applicatives first. I learned a new word today, “Sisyphean.”
*From:* Beginners [mailto:beginners-bounces@haskell.org] *On Behalf Of * Frank *Sent:* Tuesday, August 26, 2014 7:33 PM *To:* The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell *Subject:* [Haskell-beginners] LYAHFGG, chapter 11 question
About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I *taught* My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents?
Sincerely,
Frank D. Martinez
-- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

I actually found the Typeclassopedia's explanation of functors,
applicatives and monads fairly intuitive, in spite of its intimidating
appearance. You can find it here
http://www.haskell.org/haskellwiki/Typeclassopedia
Best wishes,
Karl (Karolis) Velicka
On 29 August 2014 16:00, Gareth
Actually, I remember that that chapter being difficult too, so much so that I don't think I finished it. It might be worth coming back to that chapter later, after you have more practical experience.
In the mean time though, if I could tell you only one fact about how to use Applicative, it would be this.
Say you have some pure function:
f :: Int -> Int -> Int -> Int
And some values that may or may not be in the context of some Applicative functor (let's say Maybe)
x :: Maybe Int y :: Int z :: Maybe Int
Then you can call f like this:
(f <$> x <*> pure y <*> z ) :: Maybe Int
So if you were in the middle of some do notation you could
do myF <- f <$> x <*> pure y <*> z ...
rather than the more painful
do x' <- x z' <- z let myF = f x' y z' ...
On Wed, Aug 27, 2014 at 10:22 AM, Peter Hall
wrote: I learned a new word today, “Sisyphean.”
Me too! :)
Peter
On 27 August 2014 04:21, Jeff C. Britton
wrote: I had originally encountered problems at this point myself. I lost motivation because I had just had this feeling that programming with applicatives was just not going to be fun, and it was beginning to seem like Haskell programming might involve a lot of this. I put the book down for about 1 year. Somewhere I came across an article on Monads that changed my mind. I started over and am now almost done with Chapter 13. This time around things are looking a lot cooler. I think chapters 11,12, and 13 may lack the motivational information to keep one going. I can say that the author Miran Lipovaca really does a great job of explaining this material. I don’t think you are going to find a better source. Absolutely every step of the way is laid out in painstaking detail. Plus there are constant reminders of material that was just covered that is relevant to the immediate situation. All I can say is go slow and make sure you understand every detail before proceeding. Keep at it regularly so as not to forget important terms. Go back and reread if necessary. Have the confidence that it will be worthwhile. The Monad chapters are little bit more interesting, but you will need to understand the applicatives first. I learned a new word today, “Sisyphean.”
From: Beginners [mailto:beginners-bounces@haskell.org] On Behalf Of Frank Sent: Tuesday, August 26, 2014 7:33 PM To: The Haskell-Beginners Mailing List - Discussion of primarily beginner-level topics related to Haskell Subject: [Haskell-beginners] LYAHFGG, chapter 11 question
About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I taught My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents?
Sincerely,
Frank D. Martinez
-- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

I've found LYAH beginning ca. the Functors material to become difficult for some people based on my experiences and the people I've worked with. Difficult in the sense of getting a forest-eye view or essence of what they are and what they mean. At this point, I generally recommend people flip over to cis194. NICTA course is an excellent follow-up as well and communicates what Functor, Applicative, and Monad are in a way that is unmistakable. My detailed guide is here: https://github.com/bitemyapp/learnhaskell There's also the #haskell, #haskell-beginners, and #nicta-course IRC channels on Freenode if you'd like interactive help. HTH, Chris On 08/26/2014 09:33 PM, Frank wrote:
About "Learn You a Haskell ...", is it My imagination or is chapter 11 absurdly long and/or thick? I can (and have) read a 100+ page U.S. Supreme Court ruling, readily understand it, and be able to explain it in plain English, with next to zero trouble. I spend every work day reading, parsing, interpreting, and using, the ISO C++ standard. I /taught/ My undergraduate Physics IV class while simultaneously taking it. Yet, chapter 11 feels as if it goes on and on to the point I easily forget what I read just a few lines before, rendering comprehension of the same an almost Sisyphean task. Is it just Me? Am I just tired? Is there an alternative resource for understanding the concepts that particular chapter presents?
Sincerely, Frank D. Martinez
-- P.S.: I prefer to be reached on BitMessage at BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6
_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners
participants (9)
-
Brandon Allbery
-
Chris Allen
-
David McBride
-
Frank
-
Gareth
-
Jeff C. Britton
-
Karolis Velicka
-
Matthew Moppett
-
Peter Hall