Comments on: More fun with Cabal, visualising dependencies http://therning.org/magnus/archives/534 Incoherent mumblings Tue, 24 Aug 2010 06:00:57 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: Magnus http://therning.org/magnus/archives/534/comment-page-1#comment-171533 Magnus Fri, 27 Feb 2009 19:20:57 +0000 http://therning.org/magnus/?p=534#comment-171533 <p>As Duncan pointed out in a comment to <a href="http://therning.org/magnus/archives/523" rel="nofollow">my earlier post</a> I should have been using <code>parsePackageDescription</code> instead of <code>readPackageDescription</code>. With that knowledge I rewrote <code>readCabalFile</code> like this:</p> <pre lang="haskell"> readCabalFile fn = let translateParseResult (ParseFailed _) = Nothing translateParseResult (ParseOk _ gpd) = Just gpd in bracket (openFile fn ReadMode) hClose (\ h -> do contents <- hGetContents h return $! translateParseResult $ parsePackageDescription contents) </pre> <p>No more manual deletion of cabal files necessary :-)</p> As Duncan pointed out in a comment to my earlier post I should have been using parsePackageDescription instead of readPackageDescription. With that knowledge I rewrote readCabalFile like this:

readCabalFile fn = let
        translateParseResult (ParseFailed _) = Nothing
        translateParseResult (ParseOk _ gpd) = Just gpd
    in bracket (openFile fn ReadMode) hClose
        (\ h -&gt; do
            contents &lt;- hGetContents h
            return $! translateParseResult $ parsePackageDescription contents)

No more manual deletion of cabal files necessary :-)

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