[Haskell-cafe] Package bounds approximation

[Alois Cochard]

Hi Ernesto,

What I do in that case it that I browse thru the old version number on
hackage until I find one which match ~ the time of the platform I'm
targeting, and I try to compile with it.
That is the theory, and it can work not so bad if you do each you had a new
dep... a pain if you have to do it retroactively though.

Thanks Daniel! I'll definitely give it a try :-)


On 4 September 2014 09:51, Ernesto Rodriguez <neto at netowork.me> wrote:

> Hi Alois,
>
> That certainly is an option. How well does it work with packages that are
> not part of the Haskell Platform. Do you simply try the oldest compatible
> versions of those packages?
>
> Cheers
>
>
> On Wed, Sep 3, 2014 at 8:51 AM, Alois Cochard <alois.cochard at gmail.com>
> wrote:
>
>> Hi Ernesto,
>>
>> I was looking to solve this problem a while ago, but I didn't found a
>> satisfactory tool.
>>
>> What I do atm, is trying to compile using versions of an old haskell
>> platform (like last year or something...)
>>
>> I hope that help, and I would to find an automated way of doing it.
>>
>> Cheers
>> On Sep 3, 2014 2:35 PM, "Ernesto Rodriguez" <neto at netowork.me> wrote:
>>
>>> Hi Adam,
>>>
>>> Thanks for your suggestion. As I undersdand, the flag looks at the
>>> dependencies specified by the cabal file and simply inverts the package
>>> version solving algorithm to try out older packages before newer. I am
>>> trying to solve a different problem.
>>>
>>> Sometime, (at least myself) I specify a particular lower bound in my
>>> cabal file that simply matches whatever was installed when I did cabal
>>> install. The package might work with older versions but checking this
>>> manually is a bit tedious. I would like to have a tool which I can run on
>>> my project and it will give me an approximation of the lowest possible
>>> version I can use for each of the dependencies in my project. If all
>>> packages included more faithful information about what is the lowest
>>> possible bound, it would reduce a lot of dependency hell.
>>>
>>> Cheers,
>>>
>>> Ernesto
>>>
>>>
>>> On Wed, Sep 3, 2014 at 5:40 AM, Adam Bergmark <adam at bergmark.nl> wrote:
>>>
>>>> It might be interesting to revive this PR:
>>>> https://github.com/haskell/cabal/pull/1309
>>>>
>>>> - Adam
>>>>
>>>>
>>>>
>>>> On Wed, Sep 3, 2014 at 10:48 AM, Ernesto Rodriguez <neto at netowork.me>
>>>> wrote:
>>>>
>>>>> Dear Cafe,
>>>>>
>>>>> I was wondering if there exists a tool to approximate what would be
>>>>> the minimal versions of the dependencies required by a package.
>>>>>
>>>>> I know that calculating this exactly is a bit intractable, but I was
>>>>> considering whether a tool that works as follows would work:
>>>>>
>>>>> 1) Compile the package with known to work dependencies
>>>>> 2) For each version of dependency as d:
>>>>>         For each function in d used by My Package:
>>>>>              * Perform unification of the resulting type when compiled
>>>>> with known to work dependencies
>>>>>                and the type exported by the api of the version of the
>>>>> dependency in consideration.
>>>>>          If all unifications succeeds, mark the version as compatible,
>>>>> incompatible otherwise
>>>>>
>>>>> This approximation is obviously not complete. Nevertheless, I would
>>>>> like to get opinions about whether this would be a good/useful/feasible
>>>>> approximation? Does the current GHC api export enough functionality for
>>>>> this package to be feasible? Are there alternatives? I was consider doing
>>>>> this as my `hack` during the high energy, intense no-sleep jacobsHack!
>>>>> <http://jacobshack.com> hackathon, do you think it would be a good
>>>>> idea?
>>>>>
>>>>> Thank you for the opinions and best regards,
>>>>>
>>>>> Ernesto Rodriguez
>>>>>
>>>>> --
>>>>> Ernesto Rodriguez
>>>>>
>>>>> Masters Student
>>>>> Computer Science
>>>>> Utrecht University
>>>>>
>>>>> www.netowork.me
>>>>> github.com/netogallo
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Haskell-Cafe mailing list
>>>>> Haskell-Cafe at haskell.org
>>>>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> Ernesto Rodriguez
>>>
>>> Masters Student
>>> Computer Science
>>> Utrecht University
>>>
>>> www.netowork.me
>>> github.com/netogallo
>>>
>>>
>>>
>>> _______________________________________________
>>> Haskell-Cafe mailing list
>>> Haskell-Cafe at haskell.org
>>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>>>
>>>
>
>
> --
> Ernesto Rodriguez
>
> Masters Student
> Computer Science
> Utrecht University
>
> www.netowork.me
> github.com/netogallo
>
>
>


-- 
*Λ\ois*
http://twitter.com/aloiscochard
http://github.com/aloiscochard
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20140904/724ca1d3/attachment-0001.html>