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. Simplifying a 'split' function (Ben Sanders)
2. Re: Simplifying a 'split' function (Thomas Davie)
3. Re: Simplifying a 'split' function (Ertugrul Soeylemez)
4. Re: Simplifying a 'split' function (Ben Sanders)
5. Selecting a GUI toolkit (Daniel Carrera)
6. Re: Selecting a GUI toolkit (Felipe Lessa)
7. Re: Selecting a GUI toolkit (Daniel Carrera)
8. Re: Selecting a GUI toolkit (Andy Stewart)
9. Re: Selecting a GUI toolkit (Felipe Lessa)
10. List Function (Nathan Holden)
----------------------------------------------------------------------
Message: 1
Date: Wed, 29 Apr 2009 12:00:59 -0700
From: Ben Sanders <[email protected]>
Subject: [Haskell-beginners] Simplifying a 'split' function
To: [email protected]
Message-ID:
<[email protected]>
Content-Type: text/plain; charset=ISO-8859-1
In looking through a merge sort implementation example, I came across this code:
split :: [a] -> [[a]]
split [] = []
split (x:xs) = [x] : split xs
I would have written the same code as
split :: [a] -> [[a]]
split = map (: [])
Is there any particular difference here (other than explicit
recursion)? And is there any other nicer way to write it?
Thanks,
Ben Sanders
------------------------------
Message: 2
Date: Wed, 29 Apr 2009 21:55:05 +0200
From: Thomas Davie <[email protected]>
Subject: Re: [Haskell-beginners] Simplifying a 'split' function
To: Ben Sanders <[email protected]>
Cc: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
On 29 Apr 2009, at 21:00, Ben Sanders wrote:
> In looking through a merge sort implementation example, I came
> across this code:
>
> split :: [a] -> [[a]]
> split [] = []
> split (x:xs) = [x] : split xs
>
> I would have written the same code as
>
> split :: [a] -> [[a]]
> split = map (: [])
>
> Is there any particular difference here (other than explicit
> recursion)? And is there any other nicer way to write it?
How about map pure. I do like the robot monkey though :)
Bob
------------------------------
Message: 3
Date: Wed, 29 Apr 2009 21:56:05 +0200
From: Ertugrul Soeylemez <[email protected]>
Subject: [Haskell-beginners] Re: Simplifying a 'split' function
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset=US-ASCII
Ben Sanders <[email protected]> wrote:
> In looking through a merge sort implementation example, I came across
> this code:
>
> split :: [a] -> [[a]]
> split [] = []
> split (x:xs) = [x] : split xs
>
> I would have written the same code as
>
> split :: [a] -> [[a]]
> split = map (: [])
>
> Is there any particular difference here (other than explicit
> recursion)?
No.
> And is there any other nicer way to write it?
Yes:
split = fmap return
Greets,
Ertugrul.
--
nightmare = unsafePerformIO (getWrongWife >>= sex)
http://blog.ertes.de/
------------------------------
Message: 4
Date: Wed, 29 Apr 2009 13:12:07 -0700
From: Ben Sanders <[email protected]>
Subject: Re: [Haskell-beginners] Simplifying a 'split' function
To: [email protected]
Message-ID:
<[email protected]>
Content-Type: text/plain; charset=ISO-8859-1
> How about map pure. I do like the robot monkey though :)
>
> Bob
What is 'map pure'?
And it took me a minute to figure out where you were getting 'robot
monkey' from :)
> split = fmap return
>Greets,
>Ertugrul.
Awesome! Thanks!!
------------------------------
Message: 5
Date: Thu, 30 Apr 2009 00:11:26 +0200
From: Daniel Carrera <[email protected]>
Subject: [Haskell-beginners] Selecting a GUI toolkit
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hello,
This question is just idle curiosity. I don't actually plan to write a
desktop GUI program. With that said, what library would you recommend to
someone who wants to write a cross-platform desktop app with Haskell?
Consider the following requirements:
1) Cross-platform. Windows, Linux and preferably OS X too.
2) Maintained, stable, mature, documented, etc.
3) Easy to use.
Notice that this has much to do with the Haskell bindings. For example,
Qt might be a fabulous toolkit, but qtHaskell might be immature (it
looks like it started in Dec 2007).
wxHaskell looks good. I like the idea behind wxWidgets, but I have never
used it (or any GUI toolkit for that matter).
Thank you for your input.
Cheers,
Daniel.
------------------------------
Message: 6
Date: Wed, 29 Apr 2009 19:33:25 -0300
From: Felipe Lessa <[email protected]>
Subject: Re: [Haskell-beginners] Selecting a GUI toolkit
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
If I were to write one right now (and I might actually need in a
few days), I'd use Gtk2Hs.
Cons:
- Does not fit Haskell's style.
- Very imperative, everything in IO.
Pros:
- Terrific binding: (almost) complete, working, tested.
- Multi-platform (as far as Gtk itself is).
- If you need, reading Gtk's C docs is straightforward.
- Seamless integration with Cairo (yay!).
- ... (probably more)
I already used Gtk on other languages before Haskell, though, so
I'm somewhat biased.
--
Felipe.
------------------------------
Message: 7
Date: Thu, 30 Apr 2009 00:40:54 +0200
From: Daniel Carrera <[email protected]>
Subject: Re: [Haskell-beginners] Selecting a GUI toolkit
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi Felipe,
I think I read somewhere that Gtk2Hs is the more active project, so it
might be more mature. On the other hand, Gtk kinda sucks on Mac OS X. I
hate how Gimp or GnuCash look when I run them on OS X. On Windows Gtk
runs fine except that the file browser looks out of place.
Daniel.
Felipe Lessa wrote:
> If I were to write one right now (and I might actually need in a
> few days), I'd use Gtk2Hs.
>
> Cons:
> - Does not fit Haskell's style.
> - Very imperative, everything in IO.
>
> Pros:
> - Terrific binding: (almost) complete, working, tested.
> - Multi-platform (as far as Gtk itself is).
> - If you need, reading Gtk's C docs is straightforward.
> - Seamless integration with Cairo (yay!).
> - ... (probably more)
>
> I already used Gtk on other languages before Haskell, though, so
> I'm somewhat biased.
>
> --
> Felipe.
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
------------------------------
Message: 8
Date: Thu, 30 Apr 2009 08:21:08 +0800
From: Andy Stewart <[email protected]>
Subject: [Haskell-beginners] Re: Selecting a GUI toolkit
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
Hi Daniel,
Daniel Carrera <[email protected]> writes:
> Hello,
>
> This question is just idle curiosity. I don't actually plan to write a
> desktop GUI program. With
> that said, what library would you recommend to someone who wants to write a
> cross-platform desktop
> app with Haskell?
>
> Consider the following requirements:
>
> 1) Cross-platform. Windows, Linux and preferably OS X too.
> 2) Maintained, stable, mature, documented, etc.
> 3) Easy to use.
I use gtk2hs, it yes to all your need above.
I use gtk2hs-0.10.0 with GHC 6.10 (6.10.1 or 6.10.2) in Ubuntu (or Debian).
Below is detail install method:
1) Install GHC 6.10, :)
2) Install depend libraries:
sudo aptitude install automake libglade2-dev libgtksourceview-dev
libgtksourceview2.0-dev libgconf2-dev librsvg2-dev
libgstreamer-plugins-base0.10-dev libgstreamer0.10-dev libgtkglext1-dev
libgnomevfs2-dev xulrunner-dev -y
3) Download gtk2hs-0.10.0:
http://downloads.sourceforge.net/gtk2hs/gtk2hs-0.10.0.tar.gz
4) Compile gtk2hs-0.10.0:
autoconf && ./configure --enable-docs && make && sudo make install
And this have tutorial that introduce how to use gtk2hs:
http://darcs.haskell.org/gtk2hs/docs/tutorial/Tutorial_Port/
-- Andy
>
> Notice that this has much to do with the Haskell bindings. For example, Qt
> might be a fabulous
> toolkit, but qtHaskell might be immature (it looks like it started in Dec
> 2007).
>
> wxHaskell looks good. I like the idea behind wxWidgets, but I have never used
> it (or any GUI toolkit
> for that matter).
>
> Thank you for your input.
>
> Cheers,
> Daniel.
------------------------------
Message: 9
Date: Wed, 29 Apr 2009 22:15:25 -0300
From: Felipe Lessa <[email protected]>
Subject: Re: [Haskell-beginners] Selecting a GUI toolkit
To: [email protected]
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
On Thu, Apr 30, 2009 at 12:40:54AM +0200, Daniel Carrera wrote:
> I think I read somewhere that Gtk2Hs is the more active project, so it
> might be more mature. On the other hand, Gtk kinda sucks on Mac OS X. I
> hate how Gimp or GnuCash look when I run them on OS X. On Windows Gtk
> runs fine except that the file browser looks out of place.
Although I don't have access to a Mac, people usually don't like
Gtk there. But there seems to be a native port somewhere that is
going to be merged into Gtk+ someday :).
Now, good support today for Mac OS X would be my only reason to
go through the wxWindows route. I use Gtk+ because back in the
days that I tried wxWindows, it had a terrible appearence when
using Gtk as a backend, but probably things improved since then.
--
Felipe.
------------------------------
Message: 10
Date: Wed, 29 Apr 2009 22:25:43 -0400
From: Nathan Holden <[email protected]>
Subject: [Haskell-beginners] List Function
To: [email protected]
Message-ID:
<[email protected]>
Content-Type: text/plain; charset="iso-8859-1"
I don't know what you'd call it. Is there a function in any of the basic
functions that does this something like this:
Sending two lists, [1,2,3] and [2,3,4] it would return
[(1,4),(1,5),(1,6),(2,4),(2,5),(2,6),(3,4),(3,5),(3,6)]. I managed to code
my way into returning a list of lists, which works. But it seemed like a
very basic list/matrix function, so I honestly believe that the Haskell
designers probably would've put it in.
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://www.haskell.org/pipermail/beginners/attachments/20090429/16efece4/attachment.htm
------------------------------
_______________________________________________
Beginners mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/beginners
End of Beginners Digest, Vol 10, Issue 32
*****************************************
