[Haskell-beginners] a problem with maps

[aditya siram]

Ertugul,
I admire your passion for rigor and discipline. It is not natural for
me but I am slowly coming to the same place.

I also feel that Haskell development is like learning to play music.
I've seen many a student (myself included) turn away from an
instrument because of an over-emphasis on scales, arpeggios etc. and
less on playing what sounds good. It is true that eventually to play
seriously some understanding of that theory is required but the
musician will come to that conclusion on their own.

They will hear a pattern over and over and wonder if it has a name -
then you show them the major scale and it will all make sense because
it will be a solution to a problem, not a solution waiting for a
problem.

In some ways I feel that the Haskell community because of their
expertise and enthusiasm gives users answers to questions they haven't
asked yet. When they do (inevitably) ask your awesome monad tutorial
(which helped me a great deal) will be there.

-deech

On Sat, Jul 23, 2011 at 6:39 PM, Ertugrul Soeylemez <es at ertes.de> wrote:
> David Place <d at vidplace.com> wrote:
>
>> > Point taken, but to get serious with Haskell you will want to learn
>> > applicative functors and at least the function arrow anyway.
>>
>> Interesting thoughts, Ertugrul.  I would argue that you can get very
>> serious with Haskell without understanding applicative functors and
>> the function arrow.  The very basic aspects of the language (the type
>> system, higher-order functions, lazy evaluation, etc…) are already so
>> powerful, that you really don't need to add complexity to simple
>> programs by including some of the more obscure extensions.  I could
>> see if it made the code substantially more compact.  In this case, it
>> makes the code more verbose as you need to import the two modules to
>> do something which can be so trivially expressed as an abstraction.
>
> Haskell application development is more than just the language.  The
> language itself is very powerful, yes, but serious applications I write
> usually have quite a few dependencies.  If you want to reinvent the
> wheel for everything, then yes, I'm exaggerating.  Personally I don't
> want to, because there are great libraries and design patterns out
> there, for which you simply need to understand more than just the
> language.
>
> It's as simple as this:  To get serious with Haskell, you need to
> understand Haskell monads.  Understanding them implies understanding
> applicative functors (not necessarily the applicative style).  For many
> of the useful libraries you will want to go further and understand monad
> transformers and more.
>
> I'm not talking about any ideals here.  I'm talking about real world
> application development, which is what I am doing.
>
>
>> When you write a program, do you think of it as a document only for
>> the compiler to understand, or might some other people need to
>> understand it someday?
>
> "It"?  For me type signatures are specification for the compiler and
> documentation for humans, along with Haddock-style comments.  My code is
> usually very well documented.  In most cases Haddock shows me a coverage
> of 100% for all of my source files, and every top-level and
> 'where'-definition has a type signature.  I'm very rigorous here.
>
> All of the power I get from Haskell itself, the base library and the
> many libraries I use I view as tools to get stuff done quickly, safely
> and elegantly.  As said, there is always a simpler way to write stuff,
> but I have a certain style, which I follow consistently, and in that
> style I write 'second pure'.  That's it.
>
> Why not '(:[])'?  Simply because I hate it and find it confusing.  Why
> not 'return'?  Because I write my code reasonably general.  Not that
> using 'return' would change the type signature in question, but it is
> just my style.  In a do-block I use 'return'.  Everywhere else I use
> 'pure'.  Consistently.  Why 'second'?  Because it's convenient.
>
>
> Greets,
> Ertugrul
>
>
> --
> nightmare = unsafePerformIO (getWrongWife >>= sex)
> http://ertes.de/
>
>
>
> _______________________________________________
> Beginners mailing list
> Beginners at haskell.org
> http://www.haskell.org/mailman/listinfo/beginners
>