Send Beginners mailing list submissions to
[email protected]
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
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Beginners digest..."
Today's Topics:
1. Re: Functors and Applicatives; I'm just not getting it ...
(Adam Mesha)
----------------------------------------------------------------------
Message: 1
Date: Sun, 19 Oct 2014 12:16:59 +0300
From: Adam Mesha <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] Functors and Applicatives; I'm just
not getting it ...
Message-ID:
<CAPFOCZdA8HyrMZBsYj673EOTitixmJKZH-+RJU9iwOfTFUQu=g...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
The way I have come to understand them (based on playing around with them
and various tutorials) is that a functor is a mappable, something that can
be mapped. Or, since fmap is equivalent to liftM, you could call them
liftables. So if I have a function of type a -> b and a functor (let's say
Maybe), then it makes sense that I can automatically create a function
Maybe a -> Maybe b (thus lifting the function into the Maybe functor, or
mapping a to b through (over/using) the Maybe functor).
2014-10-19 1:37 GMT+03:00 Frank <[email protected]>:
> I've had a go at LYAH and CIS 194 and the Typeclassopedia and I just don't
> get get functors and applicatives. I'm simply not understanding them, what
> the various symbols/keywords mean, what they represent, how to think of
> them, etc. Nothing. Is there any kind of documented model I should be
> considering? Is there a "functors and applicatives for Dummies" I should
> read? Should I just give it up, not bother with Haskell and just stick to
> scheme/ruby/C++?
>
> --
> P.S.: I prefer to be reached on BitMessage at
> BM-2D8txNiU7b84d2tgqvJQdgBog6A69oDAx6
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
>
--
Adam Mesha <[email protected]>
Life is either a daring adventure, or nothing. - Helen Keller
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://www.haskell.org/pipermail/beginners/attachments/20141019/066bc743/attachment-0001.html>
------------------------------
Subject: Digest Footer
_______________________________________________
Beginners mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/beginners
------------------------------
End of Beginners Digest, Vol 76, Issue 14
*****************************************
