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: Is there an "unscan" function? (Stephen Tetley)
2. Can I upload file using http-enumerator, hxt? (??????? ???)
3. gui pkgs (Andy)
----------------------------------------------------------------------
Message: 1
Date: Fri, 13 Jan 2012 18:19:49 +0000
From: Stephen Tetley <[email protected]>
Subject: Re: [Haskell-beginners] Is there an "unscan" function?
Cc: [email protected]
Message-ID:
<cab2tprdwb+oys03_nfb8uve0pojirfwkkvayffu_sz0ck9w...@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Hi Jeffrey
My version actually contains an error, it should be:
unscan :: (a -> a -> b) -> [a] -> [b]
unscan f (a:b:bs) = f a b : unscan f (b:bs)
unscan _ _ = []
A slightly less concise, but optimized version avoids putting the
second element back in a list:
unscan f (a:b:bs) = f a b : go b bs
where
go _ [] = []
go x (z:zs) = f x z : go z zs
unscan _ _ = []
The first mention of "speed" for traversing lists at different rates
I've seen was in the paper "There and Back Again" by Olivier Danvy and
Mayer Goldberg.
http://www.brics.dk/RS/02/12/BRICS-RS-02-12.pdf
Best wishes
Stephen
------------------------------
Message: 2
Date: Sat, 14 Jan 2012 02:44:02 +0700
From: ??????? ??? <[email protected]>
Subject: [Haskell-beginners] Can I upload file using http-enumerator,
hxt?
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain
Hello.
Can I upload file using http-enumerator, hxt?
What best way to take a html page from one server, maybe make some
transformation of this html and upload it (transformed) to other server?
I can use hxt to download file and to do some transformation. But how can I
upload it to other server?
------------------------------
Message: 3
Date: Fri, 13 Jan 2012 15:34:24 -0500
From: Andy <[email protected]>
Subject: [Haskell-beginners] gui pkgs
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
Hi
I'm trying to create a calculator in Haskell, something like the one
in the enclosed image. To program the gui , I thought i might use a
toolkit such as wxHaskell to create the buttons and frame etc.. I
followed all the instructions on the wxHaskell homepage and everything
seemed to install properly. Next I tried to use it with ghci, but to no
avail. It seems you have to register wxHaskell with ghci by using a
command like <ghci -package wx> but that crashes . Every tutorial I read
didn't work. Does anyone have a clear set of instructions,that does
work? Also, is there a better toolkit for doing guis than wxHaskell? I
tried Glade, but it's so bug-ridden I couldn't get anything done. I need
help.
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://www.haskell.org/pipermail/beginners/attachments/20120113/1ace9cce/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screenshot at 2012-01-13 14:27:42.png
Type: image/png
Size: 25811 bytes
Desc: not available
URL:
<http://www.haskell.org/pipermail/beginners/attachments/20120113/1ace9cce/attachment.png>
------------------------------
_______________________________________________
Beginners mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/beginners
End of Beginners Digest, Vol 43, Issue 17
*****************************************
