How to know the build dependencies?

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Re: [Haskell-cafe] [cabal] How to...

Magicloud Magiclouds

13 Jun 2009 13 Jun '09

10:22 p.m.

Hi, I am learning to use cabal for my code. Just when I start, I met a question, is there an easy way to find out what packages my code depends? Thanks.

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Gwern Branwen

13 Jun 13 Jun

11:13 p.m.

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On Sat, Jun 13, 2009 at 10:22 PM, Magicloud Magiclouds wrote:

...

Hi, I am learning to use cabal for my code. Just when I start, I met a question, is there an easy way to find out what packages my code depends?

Thanks.

Not really. The easiest way is to just build your code and add every package Cabal complains about being hid into your build-depends. (Usually this won't take more than a minute or 3 if you're toggling between a terminal and an editor.) - -- gwern -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEAREKAAYFAko0arEACgkQvpDo5Pfl1oJbNACfYNB+oScSsiwF3qwZMHzu3AjM s24An3tcamliH1rJzZiNg1EqjTLLYzzo =7Fgw -----END PGP SIGNATURE-----

Deniz Dogan

14 Jun 14 Jun

6:05 a.m.

2009/6/14 Gwern Branwen :

...

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On Sat, Jun 13, 2009 at 10:22 PM, Magicloud Magiclouds wrote:

...
Hi, I am learning to use cabal for my code. Just when I start, I met a question, is there an easy way to find out what packages my code depends?

Thanks.

Not really. The easiest way is to just build your code and add every package Cabal complains about being hid into your build-depends. (Usually this won't take more than a minute or 3 if you're toggling between a terminal and an editor.)

- -- gwern

Someone really ought to write a tool for this... -- Deniz Dogan

Gwern Branwen

10:12 a.m.

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On Sun, Jun 14, 2009 at 6:05 AM, Deniz Dogan wrote:

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Someone really ought to write a tool for this...

Well, it's an issue of time. Just building and adding the deps is fast and straightforward. A tool I'd need to know about, have installed, and remember to use in the middle of a Cabalizing session. The people who most need such a tool are those who are least likely to use it. And given the overhead, it's unclear that it would actually save time. Sometimes, somethings aren't worth automating. Now, if someone were to create such a tool and integrate it into 'mkcabal', then it might make sense. You could create the basic .cabal with the build-depends filled in. But as a separate tool it's too small a task to handle. Even memorizing the -show-iface or - -ddump-types options may not be worthwhile - how often does one create Cabal packages from scratch? - -- gwern -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEAREKAAYFAko1BWEACgkQvpDo5Pfl1oKvigCeO7ABRVr/9+kT62dIFpo0k5+f y/AAnR6wLaDpX5/lZPqQzB/Wb4kuj8i9 =L2iA -----END PGP SIGNATURE-----

Deniz Dogan

10:14 a.m.

2009/6/14 Gwern Branwen :

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On Sun, Jun 14, 2009 at 6:05 AM, Deniz Dogan wrote:

...
Someone really ought to write a tool for this...

Well, it's an issue of time. Just building and adding the deps is fast and straightforward. A tool I'd need to know about, have installed, and remember to use in the middle of a Cabalizing session. The people who most need such a tool are those who are least likely to use it. And given the overhead, it's unclear that it would actually save time. Sometimes, somethings aren't worth automating.

Now, if someone were to create such a tool and integrate it into 'mkcabal', then it might make sense. You could create the basic .cabal with the build-depends filled in. But as a separate tool it's too small a task to handle. Even memorizing the -show-iface or - -ddump-types options may not be worthwhile - how often does one create Cabal packages from scratch?

I'm sorry, I was not aware of those flags when I wrote my message. You're right. -- Deniz Dogan

Toby Miller

12:49 p.m.

On Jun 14, 2009, at 6:05 AM, Deniz Dogan wrote:

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2009/6/14 Gwern Branwen :

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On Sat, Jun 13, 2009 at 10:22 PM, Magicloud Magiclouds wrote:

...
Hi, I am learning to use cabal for my code. Just when I start, I met a question, is there an easy way to find out what packages my code depends?

Thanks.

Not really. The easiest way is to just build your code and add every package Cabal complains about being hid into your build-depends. (Usually this won't take more than a minute or 3 if you're toggling between a terminal and an editor.)

- -- gwern

Someone really ought to write a tool for this...

Visualising the Haskell Universe « Control.Monad.Writer

Claus Reinke

6:24 a.m.

...

I am learning to use cabal for my code. Just when I start, I met a question, is there an easy way to find out what packages my code depends?

If you've managed to get your code to compile, ghc --show-iface Main.hi is perhaps the easiest way (ghc --make and ghci will also report package dependencies as they encounter them). If you're looking for the package for a particular module, ghc-pkg can help ghc-pkg find-module Control.Concurrent c:/ghc/ghc-6.10.3\package.conf: base-3.0.3.1, base-4.1.0.0 ghc-pkg find-module Data.Map c:/ghc/ghc-6.10.3\package.conf: containers-0.2.0.1 If you're looking for a minimal set of imports before hunting for packages, ghc's -ddump-minimal-imports will create a file Main.imports with that information. You could then run ghc-pkg find-module over that list. These are not the only options. Perhaps the available tools need to be advertized more?-) Claus

Krzysztof Skrzętnicki

8:41 a.m.

If your module compiles, you can get the info by passing '-ddump-types': TYPE SIGNATURES numbersTests :: Test testAverage :: Test testBindInt :: Test TYPE CONSTRUCTORS Dependent modules: [(MoresmauJP.Util.Numbers, False)] Dependent packages: [HUnit-1.2.0.3, base, ghc-prim, integer] It is, however, available only after your code has successfully compiled. Best regards Krzysztof Skrzętnicki On Sun, Jun 14, 2009 at 04:22, Magicloud Magiclouds wrote:

...

Hi, I am learning to use cabal for my code. Just when I start, I met a question, is there an easy way to find out what packages my code depends?

Thanks. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

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participants (6)

Claus Reinke
Deniz Dogan
Gwern Branwen
Krzysztof Skrzętnicki
Magicloud Magiclouds
Toby Miller