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Today's Topics:
1. Re: Category Theory (prad)
2. Re: Re: Category Theory (Dominic Phillip Mulligan)
3. Re: Category Theory (prad)
4. Compiling (Chris Saunders)
5. Re: Compiling (aditya siram)
6. Re: Compiling (Daniel Fischer)
7. Re: Compiling (Chris Saunders)
8. Re: Compiling (Chris Saunders)
9. Re: Compiling (Daniel Fischer)
10. Re: Re: Category Theory (Matt Andrew)
----------------------------------------------------------------------
Message: 1
Date: Thu, 24 Jun 2010 11:18:54 -0700
From: prad <p...@towardsfreedom.com>
Subject: [Haskell-beginners] Re: Category Theory
To: beginners@haskell.org
Message-ID: <20100624111854.51814...@gom>
Content-Type: text/plain; charset=US-ASCII
On Thu, 24 Jun 2010 20:33:01 +1000
Matt Andrew <mjsa...@gmail.com> wrote:
> I have spend some time over the last couple of days trying to get my
> head around category theory
>
i've been trying to do the same matt for a couple of days, but i have
nothing by way of explanation to offer at this stage and will eagerly
look at what responses you get here.
i have found the following useful sources though:
http://www.macs.hw.ac.uk/~dpm8/files/categories/awodey-categories.pdf
(awodey's book - it's good, but i'm having trouble filling in some of
the gaps presently)
http://en.wikiversity.org/wiki/Introduction_to_Category_Theory
(wikiuniversity course)
http://en.wikiversity.org/wiki/Introduction_to_Category_Theory
(computational category theory course by rydeheard & burstall)
http://plato.stanford.edu/entries/category-theory/
(brief synopsis from stanford encyclopedia)
(now it's just a matter of trying to figure out what they are
saying :D )
--
In friendship,
prad
... with you on your journey
Towards Freedom
http://www.towardsfreedom.com (website)
Information, Inspiration, Imagination - truly a site for soaring I's
------------------------------
Message: 2
Date: Thu, 24 Jun 2010 19:52:57 +0100
From: Dominic Phillip Mulligan <dominic.p.mulli...@googlemail.com>
Subject: Re: [Haskell-beginners] Re: Category Theory
To: beginners@haskell.org
Cc: prad <p...@towardsfreedom.com>
Message-ID: <1277405577.7454.3.ca...@dpm-laptop>
Content-Type: text/plain; charset="UTF-8"
Hi,
> i have found the following useful sources though:
>
> http://www.macs.hw.ac.uk/~dpm8/files/categories/awodey-categories.pdf
> (awodey's book - it's good, but i'm having trouble filling in some of
> the gaps presently)
I've just taken this down from my site. I didn't realise that Google
was picking this up, and I don't believe I have permission to
disseminate the file publicly (it was hosted temporarily for an internal
seminar series).
However, Steve Awodey has a copy of the book up on his website.
Thankfully, it also seems to be an improved version (i.e. the actual
publisher's proofs from his textbook) over the one that I was hosting.
You can find it here:
http://www.andrew.cmu.edu/course/80-413-713/notes/
Thanks,
Dominic
------------------------------
Message: 3
Date: Thu, 24 Jun 2010 15:19:22 -0700
From: prad <p...@towardsfreedom.com>
Subject: [Haskell-beginners] Re: Category Theory
To: beginners@haskell.org
Message-ID: <20100624151922.20ce0...@gom>
Content-Type: text/plain; charset=US-ASCII
On Thu, 24 Jun 2010 11:18:54 -0700
prad <p...@towardsfreedom.com> wrote:
> (computational category theory course by rydeheard & burstall)
>
oops i goofed on the link here.
the correct link is
http://www.cs.man.ac.uk/~david/categories/
the book applies category theory to computer science specifically
(rather than be a mathematical text on the matter) so that was something
that interested me (even though i'm a total newb at all this). it uses
the language ML.
--
In friendship,
prad
... with you on your journey
Towards Freedom
http://www.towardsfreedom.com (website)
Information, Inspiration, Imagination - truly a site for soaring I's
------------------------------
Message: 4
Date: Fri, 25 Jun 2010 00:50:06 -0400
From: "Chris Saunders" <e...@mountaincable.net>
Subject: [Haskell-beginners] Compiling
To: <beginners@haskell.org>
Message-ID: <592ed760a59c43baa267218084b34...@chrispc>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I have just started trying to learn Haskell again (I seem to have a mental
block against this language). Right now I'm using Haskell in 5 steps. I
have created the file hello.hs exactly as in the section "Write your first
Haskell program". I then opened a cmd (I'm using Windows) window in the
directory where I created hello.hs and entered "ghc -o hello hello.hs".
What follows is the output of the cmd window:
hello.hs:1:7: Not in scope: data constructor `PutStrLn'
Can someone tell me why I am having this problem?
Regards
Chris Saunders
------------------------------
Message: 5
Date: Fri, 25 Jun 2010 00:52:59 -0400
From: aditya siram <aditya.si...@gmail.com>
Subject: Re: [Haskell-beginners] Compiling
To: Chris Saunders <e...@mountaincable.net>
Cc: beginners@haskell.org
Message-ID:
<aanlktilvwrgml_954bfijyhnjmqvy3trugzdmw72s...@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Try putStrLn.
-deech
On Fri, Jun 25, 2010 at 12:50 AM, Chris Saunders <e...@mountaincable.net> wrote:
> I have just started trying to learn Haskell again (I seem to have a mental
> block against this language). Right now I'm using Haskell in 5 steps. I
> have created the file hello.hs exactly as in the section "Write your first
> Haskell program". I then opened a cmd (I'm using Windows) window in the
> directory where I created hello.hs and entered "ghc -o hello hello.hs". What
> follows is the output of the cmd window:
>
> hello.hs:1:7: Not in scope: data constructor `PutStrLn'
>
> Can someone tell me why I am having this problem?
>
> Regards
> Chris Saunders
> _______________________________________________
> Beginners mailing list
> Beginners@haskell.org
> http://www.haskell.org/mailman/listinfo/beginners
>
------------------------------
Message: 6
Date: Fri, 25 Jun 2010 07:04:54 +0200
From: Daniel Fischer <daniel.is.fisc...@web.de>
Subject: Re: [Haskell-beginners] Compiling
To: beginners@haskell.org
Message-ID: <201006250704.55074.daniel.is.fisc...@web.de>
Content-Type: text/plain; charset="iso-8859-1"
On Friday 25 June 2010 06:50:06, Chris Saunders wrote:
> I have just started trying to learn Haskell again (I seem to have a
> mental block against this language). Right now I'm using Haskell in 5
> steps. I have created the file hello.hs exactly as in the section
> "Write your first Haskell program". I then opened a cmd (I'm using
> Windows) window in the directory where I created hello.hs and entered
> "ghc -o hello hello.hs".
The matter with upper/lower case has already been treated, so I'll focus on
the command line.
Unless you know exactly that you can't use the --make option and why,
always compile with
ghc --make [other options if wanted] file[s]
without --make, you'll get some puzzling 'undefined symbol' messages from
the linker sooner rather than later.
> What follows is the output of the cmd window:
>
> hello.hs:1:7: Not in scope: data constructor `PutStrLn'
>
> Can someone tell me why I am having this problem?
>
> Regards
> Chris Saunders
------------------------------
Message: 7
Date: Fri, 25 Jun 2010 01:24:28 -0400
From: "Chris Saunders" <e...@mountaincable.net>
Subject: Re: [Haskell-beginners] Compiling
To: "aditya siram" <aditya.si...@gmail.com>
Cc: beginners@haskell.org
Message-ID: <0c066c50cb4f4c0d969b8f987682a...@chrispc>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Thanks very much Aditya. The language I use most is Eiffel which is case
insensitive so I'm not accustomed to seeing such errors.
Regards
Chris Saunders
--------------------------------------------------
From: "aditya siram" <aditya.si...@gmail.com>
Sent: Friday, June 25, 2010 12:52 AM
To: "Chris Saunders" <e...@mountaincable.net>
Cc: <beginners@haskell.org>
Subject: Re: [Haskell-beginners] Compiling
> Try putStrLn.
> -deech
>
> On Fri, Jun 25, 2010 at 12:50 AM, Chris Saunders <e...@mountaincable.net>
> wrote:
>> I have just started trying to learn Haskell again (I seem to have a
>> mental
>> block against this language). Right now I'm using Haskell in 5 steps. I
>> have created the file hello.hs exactly as in the section "Write your
>> first
>> Haskell program". I then opened a cmd (I'm using Windows) window in the
>> directory where I created hello.hs and entered "ghc -o hello hello.hs".
>> What
>> follows is the output of the cmd window:
>>
>> hello.hs:1:7: Not in scope: data constructor `PutStrLn'
>>
>> Can someone tell me why I am having this problem?
>>
>> Regards
>> Chris Saunders
>> _______________________________________________
>> Beginners mailing list
>> Beginners@haskell.org
>> http://www.haskell.org/mailman/listinfo/beginners
>>
------------------------------
Message: 8
Date: Fri, 25 Jun 2010 01:34:29 -0400
From: "Chris Saunders" <e...@mountaincable.net>
Subject: Re: [Haskell-beginners] Compiling
To: "Daniel Fischer" <daniel.is.fisc...@web.de>,
<beginners@haskell.org>
Message-ID: <f2025ef1ebb84373bf54b9985b1ab...@chrispc>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
First, thanks for the reply Daniel. I just wanted to add that I needed to
use the command line "ghc --make hello.hs. I first tried "ghc --make hello
hello.hs" and this didn't work. The second is closer to the command line
that I used when I had the case error in the source code.
Regards
Chris Saunders
--------------------------------------------------
From: "Daniel Fischer" <daniel.is.fisc...@web.de>
Sent: Friday, June 25, 2010 1:04 AM
To: <beginners@haskell.org>
Subject: Re: [Haskell-beginners] Compiling
> On Friday 25 June 2010 06:50:06, Chris Saunders wrote:
>> I have just started trying to learn Haskell again (I seem to have a
>> mental block against this language). Right now I'm using Haskell in 5
>> steps. I have created the file hello.hs exactly as in the section
>> "Write your first Haskell program". I then opened a cmd (I'm using
>> Windows) window in the directory where I created hello.hs and entered
>> "ghc -o hello hello.hs".
>
> The matter with upper/lower case has already been treated, so I'll focus
> on
> the command line.
>
> Unless you know exactly that you can't use the --make option and why,
> always compile with
>
> ghc --make [other options if wanted] file[s]
>
> without --make, you'll get some puzzling 'undefined symbol' messages from
> the linker sooner rather than later.
>
>> What follows is the output of the cmd window:
>>
>> hello.hs:1:7: Not in scope: data constructor `PutStrLn'
>>
>> Can someone tell me why I am having this problem?
>>
>> Regards
>> Chris Saunders
>
> _______________________________________________
> Beginners mailing list
> Beginners@haskell.org
> http://www.haskell.org/mailman/listinfo/beginners
------------------------------
Message: 9
Date: Fri, 25 Jun 2010 11:09:16 +0200
From: Daniel Fischer <daniel.is.fisc...@web.de>
Subject: Re: [Haskell-beginners] Compiling
To: "Chris Saunders" <e...@mountaincable.net>
Cc: beginners@haskell.org
Message-ID: <201006251109.16213.daniel.is.fisc...@web.de>
Content-Type: text/plain; charset="iso-8859-1"
On Friday 25 June 2010 07:34:29, Chris Saunders wrote:
> First, thanks for the reply Daniel. I just wanted to add that I needed
> to use the command line "ghc --make hello.hs. I first tried "ghc --make
> hello hello.hs" and this didn't work.
If you want to redirect the output, the option is '-o',
ghc --make -o hithere hello.hs
(you needn't specify the extension, ghc --make -o hithere hello works too
[or ghc --make hello -o hithere, order of command line arguments doesn't
matter]), if no '-o' option is given, GHC defaults to the same name for the
binary as the main module [on Windows, name.exe].
> The second is closer to the
> command line that I used when I had the case error in the source code.
>
> Regards
> Chris Saunders
>
------------------------------
Message: 10
Date: Fri, 25 Jun 2010 20:48:30 +1000
From: Matt Andrew <mjsa...@gmail.com>
Subject: Re: [Haskell-beginners] Re: Category Theory
To: beginners@haskell.org
Message-ID: <m2iq57gzgh.wl%mjsa...@gmail.com>
Content-Type: text/plain; charset=US-ASCII
Thanks for the links Prad,
I actually hadn't come across any of the them, I had mainly been working
through the tutorials linked from the Haskell wiki monad page.
The two books you linked in particular look really interesting, hopefully
they'll shed some light for me. Cheers.
------------------------------
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