The hackage-db package

[Tags: bsd3, library]

This module provides simple access to the Hackage database by means of Data.Map. Suppose you wanted to implement a utility that queries the set of available versions for a given package, the following program would do the trick:

 import qualified Distribution.Hackage.DB as DB
 import Distribution.Text ( display )
 import System.Environment ( getArgs )

 main :: IO ()
 main = do
   pkgs <- getArgs
   db <- DB.readHackage
   let getVersions name = maybe [] DB.keys (DB.lookup name db)
   mapM_ (putStrLn . unwords . map display . getVersions) pkgs

When run, it would produce the following output:

 ./a.out containers deepseq cabal-install
 0.1.0.0 0.1.0.1 0.2.0.0 0.2.0.1 0.3.0.0 0.4.0.0
 1.0.0.0 1.1.0.0 1.1.0.1 1.1.0.2
 0.4.0 0.5.0 0.5.1 0.5.2 0.6.0 0.6.2 0.6.4 0.8.0 0.8.2 0.10.0 0.10.2

Note that once the database has been parsed, it can be accessed quickly, but the inital cost of reading 00-index.tar is fairly high.


Properties

Versions1.0, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7
Dependenciesbase (>=3 && <5), bytestring, Cabal, containers, directory, filepath, tar (>=0.4), utf8-string
LicenseBSD3
CopyrightPeter Simons
AuthorPeter Simons <simons@cryp.to>
MaintainerPeter Simons <simons@cryp.to>
CategoryDistribution
Home pagehttp://github.com/peti/hackage-db
Source repositoryhead: git clone git://github.com/peti/hackage-db.git
Upload dateFri Mar 29 22:52:27 UTC 2013
Uploaded byPeterSimons
DistributionsNixOS:1.7
Downloads536 total (83 in last 30 days)

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