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: list problem (Emanuel Koczwara)
2. Re: list problem (Tyler Huffman)
3. Re: "Developing Web Applications with Haskell and Yesod"
(Tim Perry)
4. Re: Good way of combining functions of type IO (Maybe a)
(Yitzchak Gale)
5. Build setup with dynamic linkining (harry)
----------------------------------------------------------------------
Message: 1
Date: Mon, 03 Mar 2014 18:40:03 +0100
From: Emanuel Koczwara <[email protected]>
To: [email protected]
Subject: Re: [Haskell-beginners] list problem
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
Hi,
W dniu 03.03.2014 18:04, Roelof Wobben pisze:
> I am studing this by following the wiki tutorial and then the Haskell
> basic tutorial.
> But if you have a better tutorial I'm happy to study this one too.
>
> Roelof
>
>
>
> Benjamin Edwards schreef op 3-3-2014 17:59:
>> The problem is that you don't seem to understand how singly linked
>> lists work. I would recommend studying this first, then understanding
>> how to append a value to the end of the list in haskell will probably
>> make a lot more sense.
>>
>>
>>
This is of course mailing list for beginners and we are happy to help
you, but your questions are _very_ basic. Please take a look at
http://learnyouahaskell.com.
Regards,
Emanuel
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://www.haskell.org/pipermail/beginners/attachments/20140303/fd64fc76/attachment-0001.html>
------------------------------
Message: 2
Date: Mon, 3 Mar 2014 10:49:16 -0700
From: Tyler Huffman <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] list problem
Message-ID:
<CAMYb46BW+crdnC1H5tSM-Q3j=oTDy1hNsKBB5CZCdJ=seob...@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
I would definitely recommend the #haskell IRC channel for simple questions
as well. Usually they're better at less complicated questions than the
Haskell Beginner mailing list.
Here's a link for some more information: (
http://www.haskell.org/haskellwiki/IRC_channel)
Best of luck!
On Mon, Mar 3, 2014 at 10:40 AM, Emanuel Koczwara <[email protected]
> wrote:
> Hi,
>
> W dniu 03.03.2014 18:04, Roelof Wobben pisze:
>
> I am studing this by following the wiki tutorial and then the Haskell
> basic tutorial.
> But if you have a better tutorial I'm happy to study this one too.
>
> Roelof
>
>
>
> Benjamin Edwards schreef op 3-3-2014 17:59:
>
> The problem is that you don't seem to understand how singly linked lists
> work. I would recommend studying this first, then understanding how to
> append a value to the end of the list in haskell will probably make a lot
> more sense.
>
>
>>
>
> This is of course mailing list for beginners and we are happy to help
> you, but your questions are _very_ basic. Please take a look at
> http://learnyouahaskell.com.
>
> Regards,
> Emanuel
>
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
>
Regards,
Tyler Huffman
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://www.haskell.org/pipermail/beginners/attachments/20140303/b56a48f9/attachment-0001.html>
------------------------------
Message: 3
Date: Mon, 3 Mar 2014 10:45:51 -0800
From: Tim Perry <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] "Developing Web Applications with
Haskell and Yesod"
Message-ID:
<CAFVgASWM5iADPsAudvaSinkQ1_zdKofrSLkGw=wio14wh6q...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
The code you posted won't run for me as listed. Several errors keep it from
running. Namely, the are several extra "[" characters and "Get" should be
"GET". Once I fixed those, the code works fine in both Chrome and Safari on
my Mac. Depending on the versions of the OS, Haskell Platform, Yesod, et
cetera your result may vary.
Good luck,
Tim
On Sun, Mar 2, 2014 at 6:33 PM, Brent Yorgey <[email protected]> wrote:
> On Sun, Mar 02, 2014 at 07:53:52PM -0500, KMandPJLynch wrote:
> > 7. I opened a Safari browser and entered: http://localhost:3000
> > 8. the following error message is displayed:
> > "Safari can't connect to Server.
> > Safari can't open the page http://localhost:3000/ because Safari
> can't connect to localhost"
>
> Try a different browser. I think I've heard similar problems
> mentioned before where the problem was some bug/lack of feature in
> Safari.
>
> -Brent
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://www.haskell.org/pipermail/beginners/attachments/20140303/a14ac1e6/attachment-0001.html>
------------------------------
Message: 4
Date: Tue, 4 Mar 2014 09:13:54 +0200
From: Yitzchak Gale <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] Good way of combining functions of
type IO (Maybe a)
Message-ID:
<caorualyqg3jx_fkw4jq_dnosf2ued75b1bms31ugn3q5och...@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Nathan H?sken wrote:
>> I want to write a function, which is basically a concatenation of
>> functions of type "IO (Maybe a)".
David McBride wrote:
> cabal install maybet
I would recommend using the standard MaybeT
type, from the transformers library that is
part of the Haskell Platform, unless you have
a special reason to use a different library
from Hackage.
David's code works fine with the transformers library,
after a slight modification of the import:
import Control.Monad.Trans.Maybe
Also - using the MaybeT monad is not the only
way to do this. Maybe comes with a whole
collection of very convenient combinators like
"maybe", "fromMaybe", etc. So you can also do
the calculation entirely in just IO without
very much extra noice. Choose the approach
that works out nicest for your particular
application.
Here is David's code, modified to do the
calculations directly in the IO monad:
f1 :: IO (Maybe Int)
f1 = return . Just $ 1
d2 :: Int -> IO (Maybe String)
d2 = return . Just . show
blah :: IO (Maybe (Int, String))
blah = do
a <- f1
b <- maybe (return Nothing) d2 a
return (a,b)
If you end up using things like
"maybe (return Nothing)" and
"fromMaybe (return Nothing)" a lot,
you can define aliases for them.
Perhaps there ought to be aliases like
that in the standard libraries somewhere...
Regards,
Yitz
------------------------------
Message: 5
Date: Tue, 4 Mar 2014 10:11:36 +0000 (UTC)
From: harry <[email protected]>
To: [email protected]
Subject: [Haskell-beginners] Build setup with dynamic linkining
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
I've removed the static libraries from a machine to save space, and
configured cabal to build both libraries and executables dynamically. This
works for everything except packages with Custom build-type (e.g. Happy),
when cabal-install will try to build setup against the non-existent static
libraries.
Is there any way to force cabal to build dist/setup dynamically?
------------------------------
Subject: Digest Footer
_______________________________________________
Beginners mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/beginners
------------------------------
End of Beginners Digest, Vol 69, Issue 9
****************************************
