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Today's Topics:
1. Errors package (Andrew Bernard)
2. Re: Errors package (Andres L?h)
3. Re: Errors package (Michael Snoyman)
4. Re: Errors package (Andrew Bernard)
5. Foldable of Foldable (Julian Birch)
----------------------------------------------------------------------
Message: 1
Date: Fri, 2 Jan 2015 23:19:05 +1100
From: Andrew Bernard <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: [Haskell-beginners] Errors package
Message-ID: <[email protected]>
Content-Type: text/plain; charset="utf-8"
When attempting to install the package ?errors? I get the following:
$ cabal install errors
Resolving dependencies...
In order, the following would be installed:
exceptions-0.6.1 (reinstall) changes: mtl-2.1.2 -> 2.2.1, transformers-0.3.0.0
-> 0.4.2.0
transformers-base-0.4.3 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
monad-control-1.0.0.1 (new version)
transformers-compat-0.3.3.4 (reinstall) changes: transformers-0.3.0.0 ->
0.4.2.0
contravariant-1.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
distributive-0.4.4 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
comonad-4.2.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
semigroupoids-4.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
bifunctors-4.2 (reinstall)
profunctors-4.3.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
free-4.10.0.1 (new version)
either-4.3.2.1 (new version)
errors-1.4.7 (new package)
cabal: The following packages are likely to be broken by the reinstalls:
temporary-1.2.0.3
ghc-mod-5.2.1.1
resourcet-1.1.2.3
yaml-0.8.9.3
stylish-haskell-0.5.11.0
persistent-sqlite-1.3.0.5
persistent-1.3.3
persistent-template-1.3.2.2
monad-logger-0.3.8
hoogle-4.2.36
conduit-extra-1.1.4.2
conduit-1.2.3
either-4.3.2
monad-journal-0.5.0.1
resource-pool-0.2.3.1
monad-control-0.3.3.0
lifted-base-0.2.3.0
io-choice-0.0.5
HTF-0.12.2.3
free-4.9
Use --force-reinstalls if you want to install anyway.
I am using the ghc platform version 7.6.3.
Is this package obsolete? Why are so many packages likely to be broken?
With Haskell, how does one know what is a proper up to date package and what is
not?
Andrew
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Message: 2
Date: Fri, 2 Jan 2015 13:27:38 +0100
From: Andres L?h <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] Errors package
Message-ID:
<CALjd_v4jEZBurE6-QGF=rsrdb16KPsfwz_orKr=c9ilf7us...@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Cabal-install doesn't always find the "best" install plan out of the
possibly many, many options available. You can try if you get a better
one that does not upgrade "transformers", by saying
cabal install errors --constraint="transformers installed"
Cheers,
Andres
On Fri, Jan 2, 2015 at 1:19 PM, Andrew Bernard <[email protected]> wrote:
> When attempting to install the package ?errors? I get the following:
>
> $ cabal install errors
> Resolving dependencies...
> In order, the following would be installed:
> exceptions-0.6.1 (reinstall) changes: mtl-2.1.2 -> 2.2.1,
> transformers-0.3.0.0
> -> 0.4.2.0
> transformers-base-0.4.3 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> monad-control-1.0.0.1 (new version)
> transformers-compat-0.3.3.4 (reinstall) changes: transformers-0.3.0.0 ->
> 0.4.2.0
> contravariant-1.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> distributive-0.4.4 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> comonad-4.2.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> semigroupoids-4.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> bifunctors-4.2 (reinstall)
> profunctors-4.3.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> free-4.10.0.1 (new version)
> either-4.3.2.1 (new version)
> errors-1.4.7 (new package)
> cabal: The following packages are likely to be broken by the reinstalls:
> temporary-1.2.0.3
> ghc-mod-5.2.1.1
> resourcet-1.1.2.3
> yaml-0.8.9.3
> stylish-haskell-0.5.11.0
> persistent-sqlite-1.3.0.5
> persistent-1.3.3
> persistent-template-1.3.2.2
> monad-logger-0.3.8
> hoogle-4.2.36
> conduit-extra-1.1.4.2
> conduit-1.2.3
> either-4.3.2
> monad-journal-0.5.0.1
> resource-pool-0.2.3.1
> monad-control-0.3.3.0
> lifted-base-0.2.3.0
> io-choice-0.0.5
> HTF-0.12.2.3
> free-4.9
> Use --force-reinstalls if you want to install anyway.
>
> I am using the ghc platform version 7.6.3.
>
> Is this package obsolete? Why are so many packages likely to be broken?
>
> With Haskell, how does one know what is a proper up to date package and what
> is not?
>
> Andrew
>
>
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
------------------------------
Message: 3
Date: Fri, 02 Jan 2015 12:28:03 +0000
From: Michael Snoyman <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] Errors package
Message-ID:
<caka2jg+ikretecq4p+mktwh5eiopmy2nhyhku_pxe4476o1...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
I'm not sure why cabal has decided that it's best to reinstall a new
version of transformers, that seems very strange to me. You can probably
work around this by running:
cabal install errors --constraint 'transformers == 0.3.0.0'
I *would* recommend upgrading to GHC 7.8, as a number of packages have
stopped supporting 7.6.3. (For the record, I don't believe any of the
packages you have installed have dropped backwards compatibility.) And
generally, I recommend using Stackage to avoid these kinds of versioning
problems. There are instructions at:
http://www.stackage.org
Fair warning: I'm the primary Stackage maintainer.
On Fri Jan 02 2015 at 2:19:20 PM Andrew Bernard <[email protected]>
wrote:
> When attempting to install the package ?errors? I get the following:
>
> $ cabal install errors
> Resolving dependencies...
> In order, the following would be installed:
> exceptions-0.6.1 (reinstall) changes: mtl-2.1.2 -> 2.2.1,
> transformers-0.3.0.0
> -> 0.4.2.0
> transformers-base-0.4.3 (reinstall) changes: transformers-0.3.0.0 ->
> 0.4.2.0
> monad-control-1.0.0.1 (new version)
> transformers-compat-0.3.3.4 (reinstall) changes: transformers-0.3.0.0 ->
> 0.4.2.0
> contravariant-1.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> distributive-0.4.4 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> comonad-4.2.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> semigroupoids-4.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> bifunctors-4.2 (reinstall)
> profunctors-4.3.2 (reinstall) changes: transformers-0.3.0.0 -> 0.4.2.0
> free-4.10.0.1 (new version)
> either-4.3.2.1 (new version)
> errors-1.4.7 (new package)
> cabal: The following packages are likely to be broken by the reinstalls:
> temporary-1.2.0.3
> ghc-mod-5.2.1.1
> resourcet-1.1.2.3
> yaml-0.8.9.3
> stylish-haskell-0.5.11.0
> persistent-sqlite-1.3.0.5
> persistent-1.3.3
> persistent-template-1.3.2.2
> monad-logger-0.3.8
> hoogle-4.2.36
> conduit-extra-1.1.4.2
> conduit-1.2.3
> either-4.3.2
> monad-journal-0.5.0.1
> resource-pool-0.2.3.1
> monad-control-0.3.3.0
> lifted-base-0.2.3.0
> io-choice-0.0.5
> HTF-0.12.2.3
> free-4.9
> Use --force-reinstalls if you want to install anyway.
>
> I am using the ghc platform version 7.6.3.
>
> Is this package obsolete? Why are so many packages likely to be broken?
>
> With Haskell, how does one know what is a proper up to date package and
> what is not?
>
> Andrew
>
>
> _______________________________________________
> Beginners mailing list
> [email protected]
> http://www.haskell.org/mailman/listinfo/beginners
>
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Message: 4
Date: Sat, 3 Jan 2015 00:21:01 +1100
From: Andrew Bernard <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] Errors package
Message-ID: <[email protected]>
Content-Type: text/plain; charset="utf-8"
Thanks so much gentlemen!
Upgrading to the Haskell Platform 7.8.3 solved all the issues completely.
The Linux Mint 17.1 apt package is currently still at 7.6.3, but there is a
generic linux binary available for 7.8.3 that works just fine.
Andrew
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Message: 5
Date: Fri, 2 Jan 2015 15:14:37 +0000
From: Julian Birch <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: [Haskell-beginners] Foldable of Foldable
Message-ID:
<CAB0TuzBBpz-Cv69hDaqEcw5AfQgbp2i9-=z4sp2grrgu1k_...@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Apologies if this isn't clear, I suspect if I understood the terminology
better I'd already have solved the problem. I've got a foldable of a
foldable of a. (Specifically `[Set a]`) and I want to be able to express
the concept that I can treat `(Foldable f1, Foldable f2) => f1 (f2 a)` as
`f3 a` i.e. a foldable of a foldable of a can be newtyped to a foldable of
a. At least, I think that's right.
Sadly, my attempts at actually expressing this concept have met with
incomprehension from GHC, could someone help me out, please?
Thanks,
Julian.
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