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Today's Topics:
1. Question regarding the ListT Monad Transformer (Tim Cowlishaw)
2. Re: run another program from within haskell program (prad)
3. Re: Question regarding the ListT Monad Transformer
(Edward Z. Yang)
4. Re: Yezod and Snap deployments to ISP (Robert Wills)
5. Re: Yezod and Snap deployments to ISP (Michael Snoyman)
----------------------------------------------------------------------
Message: 1
Date: Wed, 4 Aug 2010 18:29:24 +0100
From: Tim Cowlishaw <[email protected]>
Subject: [Haskell-beginners] Question regarding the ListT Monad
Transformer
To: [email protected]
Message-ID:
<[email protected]>
Content-Type: text/plain; charset=ISO-8859-1
Hey all,
I'm trying to get my head around the ListT Monad Transformer, and am
having trouble working out how to use it.
Essentially, I am trying to transform a type of [IO a] to IO [a] I'd
assumed that this might work something like this
Transform [IO a] to ListT IO a
call runListT to transform ListT IO a to IO [a]
..having I'd assumed that this was the correct situation to use a
Monad Transformer, as I'm layering monads around each other.
However, while the second half of the transformation above is catered
for via runListT - I can't seem to work out how to do the first -
namely, to write a function of type [IO a] -> ListT IO a . To be
honest, I'm not entirely sure I've entirely got my head around Monad
Transformers yet - does what I'm describing make any sense at all, and
if so, is there any chance you could point me in the right direction
towards implementing (and hopefully understanding) this?
Cheers,
Tim
------------------------------
Message: 2
Date: Wed, 4 Aug 2010 10:33:16 -0700
From: prad <[email protected]>
Subject: [Haskell-beginners] Re: run another program from within
haskell program
To: [email protected]
Message-ID: <20100804103316.3c347...@gom>
Content-Type: text/plain; charset=US-ASCII
On Wed, 4 Aug 2010 07:15:48 -0400
matthew coolbeth <[email protected]> wrote:
> I've never tried, but this blog post seems to do the right thing
>
thx matthew!
i found another way from real world haskell ch 20:
import System.Cmd (rawSystem)
...
rawSystem "vim" [fileName]
when i save and exit vim, i'm returned to where i left off!
--
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: 3
Date: Wed, 04 Aug 2010 13:42:02 -0400
From: "Edward Z. Yang" <[email protected]>
Subject: Re: [Haskell-beginners] Question regarding the ListT Monad
Transformer
To: Tim Cowlishaw <[email protected]>
Cc: beginners <[email protected]>
Message-ID: <1280943587-sup-2...@ezyang>
Content-Type: text/plain; charset=UTF-8
Excerpts from Tim Cowlishaw's message of Wed Aug 04 13:29:24 -0400 2010:
> However, while the second half of the transformation above is catered
> for via runListT - I can't seem to work out how to do the first -
> namely, to write a function of type [IO a] -> ListT IO a . To be
> honest, I'm not entirely sure I've entirely got my head around Monad
> Transformers yet - does what I'm describing make any sense at all, and
> if so, is there any chance you could point me in the right direction
> towards implementing (and hopefully understanding) this?
ListT IO a = IO [a], so you're looking for a function [IO a] -> IO [a].
This function is called sequence :: Monad m => [m a] -> m [a]
My best advice for you is to get rid of the newtype wrapping and unwrapping
when you're trying to an understand a monad transformer.
Cheers,
Edward
------------------------------
Message: 4
Date: Wed, 4 Aug 2010 19:30:48 +0100
From: Robert Wills <[email protected]>
Subject: Re: [Haskell-beginners] Yezod and Snap deployments to ISP
To: [email protected]
Message-ID:
<[email protected]>
Content-Type: text/plain; charset="iso-8859-1"
Webfactional doesn't provide VPS services but you can still run Haskell apps
on their servers.
http://wrwills.webfactional.com/2009/10/30/Haskell-on-a-Webfaction-Host
<http://wrwills.webfactional.com/2009/10/30/Haskell-on-a-Webfaction-Host>
-Rob
On Wed, Aug 4, 2010 at 3:50 PM, Toby Thain <[email protected]> wrote:
>
> On 3-Aug-10, at 2:11 PM, Kyle Murphy wrote:
>
> Your choice of ISP will always determine your choice of language/framework,
> and vice versa. Most cheap ISPs only support a limited subset of languages
> and/or frameworks, typically ASP.NET, PHP, or Java. Some ISPs will also
> dictate other choices, such as using a particular web server (Apache,
> Tomcat, IIS, etc.), or a particular DB such as MySQL, MS SQL, or PosgreSQL.
> On the more expensive end of choices you have dedicated servers or private
> virtual servers, where you have complete control over what you run and it's
> up to you to configure the services you want. The downside to private
> virtual servers is that they typically have fairly strict resources limits,
> such as 300M of RAM, or 5G of storage. Finally, the most expensive option is
> a co-location facility that will plug your server into their network and
> provide you backbone access, but which allows you to not only control what
> software you run, but also the hardware that it runs on.
>
> At this time, I know of no ISP that directly supports Haskell, in
> particular Happs, Yesod, or Snap, so if you want to run any of those you'll
> have to go with a dedicated server, or a virtual server. As for sending
> e-mail, and language should be able to send e-mail if you have a properly
> configured mail server that it can connect to, but the details of how to
> configure that are a bit much to put into an e-mail.
>
> If you want to play around with Yesod, I and a couple other people are
> using slicehost to run various Haskell based webapps (under a variety of
> frameworks), but be aware that it's more expensive than a lot of cheap hosts
> (~$20 a month for a basic server with 256M of RAM), and you'll be
> responsible for administering your own server, as well as having to work
> within the limited resources provided.
>
>
>
> Other than slicehost, here are some more VPS hosting options, in USA.
>
>
> - http://www.hostgator.com/ <http://www.hostgator.com/>
> - http://mediatemple.net/webhosting/<http://mediatemple.net/webhosting/>
> - http://www.gandi.net/ <http://www.gandi.net/>
> - http://www.webfaction.com/ <http://www.webfaction.com/>
> - http://linode.com/ <http://linode.com/>
> - http://laughingsquid.us/ <http://laughingsquid.us/>
> - http://aws.amazon.com/ec2/ <http://aws.amazon.com/ec2/>
> - http://www.rackspace.com/ <http://www.rackspace.com/>
> - Comparison chart (June 2010):
>
> http://advogato.org/person/etbe/diary/792.html<http://advogato.org/person/etbe/diary/792.html>
>
> --Toby
>
>
>
> -R. Kyle Murphy
> --
> Curiosity was framed, Ignorance killed the cat.
>
>
> On Tue, Aug 3, 2010 at 12:48, MH <[email protected]> wrote:
>
>> I want to build a website using haskell and deploy it to some ISP. I
>> appreciate if you help me understand the following:
>> 1. Do I need to consider using special ISP to deploy Yezod or Snap?
>> 2. Do I need to consider using special ISP to deploy any other Haskell
>> based web app?
>> 3. To start with I need to display a static content and ability to send
>> email from user submitted form. Can I send email with these Web frameworks
>> (I would appreciate the samples)?
>> 4. Can you recommend me any ISP in USA?
>>
>> Thanks a lot.
>>
>> Malik
>>
>>
>> _______________________________________________
>> Beginners mailing list
>> [email protected]
>> http://www.haskell.org/mailman/listinfo/beginners
>>
>>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
>
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
>
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Message: 5
Date: Wed, 4 Aug 2010 21:41:44 +0300
From: Michael Snoyman <[email protected]>
Subject: Re: [Haskell-beginners] Yezod and Snap deployments to ISP
To: Robert Wills <[email protected]>
Cc: [email protected]
Message-ID:
<[email protected]>
Content-Type: text/plain; charset="utf-8"
I should note that specifically Yesod can run as CGI, FastCGI, SCGI or
standalone, so serving it on shared hosting isn't a problem. The deploying
page[1] gives sample config files, and the yesod-hello[2] package provides
some runnable examples. The only trick is actually compiling the executable
for a shared host, which as implied by the blog post mentioned by Rob can be
a little tedious.
I've successfully run Yesod apps on nearlyfreespeech, but that required
installing FreeBSD in a virtual machine. I wouldn't recommend it for a
production deployment, but it might be enough for testing things out.
Regards,
Michael
[1] http://docs.yesodweb.com/yesod/deploying.html
<http://docs.yesodweb.com/yesod/deploying.html>[2]
http://github.com/snoyberg/yesod-hello
On Wed, Aug 4, 2010 at 9:30 PM, Robert Wills <[email protected]> wrote:
> Webfactional doesn't provide VPS services but you can still run Haskell
> apps on their servers.
>
> http://wrwills.webfactional.com/2009/10/30/Haskell-on-a-Webfaction-Host
>
> <http://wrwills.webfactional.com/2009/10/30/Haskell-on-a-Webfaction-Host>
> -Rob
>
>
> On Wed, Aug 4, 2010 at 3:50 PM, Toby Thain <[email protected]>wrote:
>
>>
>> On 3-Aug-10, at 2:11 PM, Kyle Murphy wrote:
>>
>> Your choice of ISP will always determine your choice of
>> language/framework, and vice versa. Most cheap ISPs only support a limited
>> subset of languages and/or frameworks, typically ASP.NET, PHP, or Java.
>> Some ISPs will also dictate other choices, such as using a particular web
>> server (Apache, Tomcat, IIS, etc.), or a particular DB such as MySQL, MS
>> SQL, or PosgreSQL. On the more expensive end of choices you have dedicated
>> servers or private virtual servers, where you have complete control over
>> what you run and it's up to you to configure the services you want. The
>> downside to private virtual servers is that they typically have fairly
>> strict resources limits, such as 300M of RAM, or 5G of storage. Finally, the
>> most expensive option is a co-location facility that will plug your server
>> into their network and provide you backbone access, but which allows you to
>> not only control what software you run, but also the hardware that it runs
>> on.
>>
>> At this time, I know of no ISP that directly supports Haskell, in
>> particular Happs, Yesod, or Snap, so if you want to run any of those you'll
>> have to go with a dedicated server, or a virtual server. As for sending
>> e-mail, and language should be able to send e-mail if you have a properly
>> configured mail server that it can connect to, but the details of how to
>> configure that are a bit much to put into an e-mail.
>>
>> If you want to play around with Yesod, I and a couple other people are
>> using slicehost to run various Haskell based webapps (under a variety of
>> frameworks), but be aware that it's more expensive than a lot of cheap hosts
>> (~$20 a month for a basic server with 256M of RAM), and you'll be
>> responsible for administering your own server, as well as having to work
>> within the limited resources provided.
>>
>>
>>
>> Other than slicehost, here are some more VPS hosting options, in USA.
>>
>>
>> - http://www.hostgator.com/ <http://www.hostgator.com/>
>> - http://mediatemple.net/webhosting/<http://mediatemple.net/webhosting/>
>> - http://www.gandi.net/ <http://www.gandi.net/>
>> - http://www.webfaction.com/ <http://www.webfaction.com/>
>> - http://linode.com/ <http://linode.com/>
>> - http://laughingsquid.us/ <http://laughingsquid.us/>
>> - http://aws.amazon.com/ec2/ <http://aws.amazon.com/ec2/>
>> - http://www.rackspace.com/ <http://www.rackspace.com/>
>> - Comparison chart (June 2010):
>>
>> http://advogato.org/person/etbe/diary/792.html<http://advogato.org/person/etbe/diary/792.html>
>>
>> --Toby
>>
>>
>>
>> -R. Kyle Murphy
>> --
>> Curiosity was framed, Ignorance killed the cat.
>>
>>
>> On Tue, Aug 3, 2010 at 12:48, MH <[email protected]> wrote:
>>
>>> I want to build a website using haskell and deploy it to some ISP. I
>>> appreciate if you help me understand the following:
>>> 1. Do I need to consider using special ISP to deploy Yezod or Snap?
>>> 2. Do I need to consider using special ISP to deploy any other Haskell
>>> based web app?
>>> 3. To start with I need to display a static content and ability to send
>>> email from user submitted form. Can I send email with these Web frameworks
>>> (I would appreciate the samples)?
>>> 4. Can you recommend me any ISP in USA?
>>>
>>> Thanks a lot.
>>>
>>> Malik
>>>
>>>
>>> _______________________________________________
>>> Beginners mailing list
>>> [email protected]
>>> http://www.haskell.org/mailman/listinfo/beginners
>>>
>>>
>> _______________________________________________
>> Beginners mailing list
>> [email protected]
>> http://www.haskell.org/mailman/listinfo/beginners
>>
>>
>>
>> _______________________________________________
>> Beginners mailing list
>> [email protected]
>> http://www.haskell.org/mailman/listinfo/beginners
>>
>>
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
>
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