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Today's Topics:
1. DB + CSV + Mail (Ari King)
2. Re: development workflow ? (Jo?o Crist?v?o)
3. Re: Functors in Haskell (Dimitri DeFigueiredo)
4. Re: Functors in Haskell (Brent Yorgey)
5. Re: development workflow ? (John M. Dlugosz)
6. Re: development workflow ? (John M. Dlugosz)
7. Re: development workflow ? (Chadda? Fouch?)
----------------------------------------------------------------------
Message: 1
Date: Tue, 29 Apr 2014 14:50:48 -0400
From: Ari King <[email protected]>
To: [email protected]
Subject: [Haskell-beginners] DB + CSV + Mail
Message-ID:
<CAPcS2ajVJfftvLn5JSx04-t36nBN_2P=xfrkc4aaff2aowo...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Hi,
I'd like to port a python script that queries a DB, writes the results to a
CSV file, and emails that file. I'd appreciate suggestions on libraries
and/or approaches that can help me achieve this.
For DB querying I was thinking of using HDBC.
Best,
Ari
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Message: 2
Date: Tue, 29 Apr 2014 20:03:12 +0100
From: Jo?o Crist?v?o <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] development workflow ?
Message-ID:
<CAAbu24omNeuCPOY8t8o50GV5zL75R8+-DOJECr=qgiwsfgj...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
> "git clone https://github.com/benl23x5/gloss"; will get you
> the latest and greatest
Or, for a recent enough cabal, and properly written cabal files, like the
one from gloss:
cabal get -s gloss
2014-04-29 18:12 GMT+01:00 Chadda? Fouch? <[email protected]>:
> On Fri, Apr 25, 2014 at 4:41 PM, John M. Dlugosz <[email protected]
> > wrote:
>
>> If you're working on a Haskell project that includes packages, and the
>> packages are in subdirectories of the source tree, how do you "build"?
>>
>> In my case, I want to alter the "gloss" package so I unpacked it, changed
>> the name to "customgloss" in the .cabal file, and installed. Meanwhile, I
>> used the package-quallified import GHC feature.
>>
>>
> While that's not the question you asked, I note that you unpacked gloss
> which probably means "cabal unpack gloss" (?). This is in general a
> terrible idea because the latest released version may not be up to the
> development version and if you want to work sanely, you'll have to put this
> code in revision control, and you won't use the same as the author and so
> on... So when you send a patch he may not be able to simply apply it to his
> latest version and then it'll sit forgotten in his mail box and your work
> will be lost for the community (ok, I may be overdoing it here...).
>
> So the sane alternative is to check on the hackage page if a repository is
> specified, like here : "git clone https://github.com/benl23x5/gloss"; will
> get you the latest and greatest, already in revision control and facilitate
> the creation of a pull request in the future (in fact if you have a github
> account, it's even better to go to this page and fork his repo to have your
> own version on github).
>
> --
> Jeda?
>
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
>
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Message: 3
Date: Tue, 29 Apr 2014 13:05:13 -0600
From: Dimitri DeFigueiredo <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] Functors in Haskell
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
Wow, this makes it very clear!
So, the object mapping is provided by the type constructor and the arrow
mapping by fmap.
Thanks :-)
Em 29/04/14 12:35, Rein Henrichs escreveu:
> Yes, this is reasonable, but it might be useful to be a bit more
> explicit about the categories involved.
>
> An instance of Functor is a functor which maps objects and arrows in
> the category of Hask (of Haskell types and functions) to... objects
> and arrows in the category of Hask. It is an endofunctor. The object
> mapping must map a type to a type and therefore must have the kind *
> -> *. This means that it is a type constructor, e.g., Maybe. The arrow
> mapping must map arrows to arrows, which means it must map functions
> to functions. fmap provides this mapping and the Functor laws in
> Haskell are of course equivalent to the laws from category theory.
>
> And while the inclusion of bottom is problematic for Hask, it is still
> possible to reason about it in a "morally correct" way
> (http://www.cse.chalmers.se/~nad/publications/danielsson-et-al-popl2006.pdf
> <http://www.cse.chalmers.se/%7Enad/publications/danielsson-et-al-popl2006.pdf>).
>
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
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Message: 4
Date: Tue, 29 Apr 2014 15:22:36 -0400
From: Brent Yorgey <[email protected]>
To: [email protected]
Subject: Re: [Haskell-beginners] Functors in Haskell
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
Right. Note, your original formulation---saying that a Functor
instance maps from Hask to some subcategory of Hask (e.g. all types of
the form Maybe X) was not wrong. It's just not a very useful way to
think about it; as Rein described it's more useful to think of Functor
instances as functors Hask -> Hask.
-Brent
On Tue, Apr 29, 2014 at 01:05:13PM -0600, Dimitri DeFigueiredo wrote:
> Wow, this makes it very clear!
>
> So, the object mapping is provided by the type constructor and the
> arrow mapping by fmap.
>
> Thanks :-)
>
>
> Em 29/04/14 12:35, Rein Henrichs escreveu:
> >Yes, this is reasonable, but it might be useful to be a bit more
> >explicit about the categories involved.
> >
> >An instance of Functor is a functor which maps objects and arrows
> >in the category of Hask (of Haskell types and functions) to...
> >objects and arrows in the category of Hask. It is an endofunctor.
> >The object mapping must map a type to a type and therefore must
> >have the kind * -> *. This means that it is a type constructor,
> >e.g., Maybe. The arrow mapping must map arrows to arrows, which
> >means it must map functions to functions. fmap provides this
> >mapping and the Functor laws in Haskell are of course equivalent to
> >the laws from category theory.
> >
> >And while the inclusion of bottom is problematic for Hask, it is
> >still possible to reason about it in a "morally correct" way
> >(http://www.cse.chalmers.se/~nad/publications/danielsson-et-al-popl2006.pdf
> ><http://www.cse.chalmers.se/%7Enad/publications/danielsson-et-al-popl2006.pdf>).
> >
> >
> >_______________________________________________
> >Beginners mailing list
> >[email protected]
> >http://www.haskell.org/mailman/listinfo/beginners
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
------------------------------
Message: 5
Date: Tue, 29 Apr 2014 14:37:10 -0500
From: "John M. Dlugosz" <[email protected]>
To: [email protected]
Subject: Re: [Haskell-beginners] development workflow ?
Message-ID: <[email protected]>
Content-Type: text/plain; charset=windows-1252; format=flowed
On 4/29/2014 12:12 PM, Chadda? Fouch? wrote:
> So the sane alternative is to check on the hackage page if a repository is
> specified, like
> here : "git clone https://github.com/benl23x5/gloss"; will get you the latest
> and greatest,
> already in revision control and facilitate the creation of a pull request in
> the future
> (in fact if you have a github account, it's even better to go to this page
> and fork his
> repo to have your own version on github).
>
Thanks. I was thinking as much if I make more than a trivial change and want
to
contribute. I was wondering if the local repository subdirectory needs to be
anyplace in
particular, or cabal "add source" just takes care of it wherever it's located?
?John
------------------------------
Message: 6
Date: Tue, 29 Apr 2014 14:37:52 -0500
From: "John M. Dlugosz" <[email protected]>
To: [email protected]
Subject: Re: [Haskell-beginners] development workflow ?
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 4/29/2014 2:03 PM, Jo?o Crist?v?o wrote:
> > "git clone https://github.com/benl23x5/gloss"; will get you
> > the latest and greatest
>
> Or, for a recent enough cabal, and properly written cabal files, like the one
> from gloss:
>
> cabal get -s gloss
>
cool!
------------------------------
Message: 7
Date: Tue, 29 Apr 2014 22:08:35 +0200
From: Chadda? Fouch? <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] development workflow ?
Message-ID:
<canfjzrztotah2ztm3a7tj5bd3df+vfewyo72fjx8qtkzzyj...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
On Tue, Apr 29, 2014 at 9:03 PM, Jo?o Crist?v?o <[email protected]>wrote:
> > "git clone https://github.com/benl23x5/gloss"; will get you
> > the latest and greatest
>
> Or, for a recent enough cabal, and properly written cabal files, like the
> one from gloss:
>
> cabal get -s gloss
>
Very nice, I didn't know this command but cabal has really become a nice
tool to put in place and keep up-to-date a development environment covering
several packages !
--
Jeda?
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