Re: [Haskell-beginners] Re: monad nomad gonad gomad

On Tue, Aug 17, 2010 at 01:59:44PM -0700, prad wrote:

On Tue, 17 Aug 2010 13:34:01 -0700 Michael Mossey wrote:

...

It looks to me like you need to work through a book like "Real World Haskell" sequentially from the beginning.

well i'm doing that too, michael. (i remember you made this suggestion to me several weeks ago and i have worked my way through a few chapters in rw and most of the haskell wiki tutorial).

Well, I may not help you, Prad, but the enormous amount of questions you've send to this mailing-list have helped me to re-discover many basic concepts of Haskell ,-) I am also trying to learn it since last January. So I can add this piece of advice for you : do not rush things. It seems you are reading too many different contents on monads lately. That's strange for someone as lazy as me who cannot digest this much amount of data in such a short time. I usually evaluate my time spend on a specific subject as the number of nights spend between each of my readings and I can say this: monads have taken me a good month of sleep to figure them out :)

what i find interesting is that you say what i'm trying to do here is complicated, because it seemed to me it was one of the simpler things that i actually understood. now i think i'm in trouble, because evidently i haven't understood it too well. :D

No it's not simple. I am not able to read Haskell code which play with database and files, so your code is already behind my understanding.

it seemed to me that in one situation i was trying to get data from a function gt which just returns a string: gt :: String -> String

in the other situation, i wanted to get the same data from a file, but can't seem to because the file is returning an IO instead of a String (in fact it is expecting [String]).

From what I remember, RWH's authors always advocate to separate monadic code from basic code. You should pause for a moment and refactor your code so you do not get caught in this situation again (situation = trying to read a file as you read a String).

If I were you, I would break my problem in even smaller chunks and try to analyze patiently how Haskell could process each individually. regards, /John P.S.: ah ! and keep posting questions on precise problems you encounter. I may be interested in them :p