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ANNOUNCE: graphviz 2999.9.0.0
by Ivan Lazar Miljenovic 26 Apr '10

26 Apr '10

I'm pleased to announce the latest version of my graphviz library that provides Haskell bindings to the Graphviz graph visualisation suite. There are numerous changes in this release, the most important of which are: * graphviz now has an FAQ and an improved README as well as its own homepage: http://projects.haskell.org/graphviz/ (as prompted by Eric Kow). * Add support for record labels; values are automatically escaped/unescaped. The `Record` and `MRecord` shapes have been added for use with these labels. Requested by Minh Thu and Eric Kow. * Add support for HTML-like values (this replaces the wrong and completely broken URL datatype). Strings are automatically escaped/unescaped. * Various parsing improvements (including a slight parsing speed increase!). In particular, graphviz is now able to parse almost all Dot graphs found on my system (including samples shipped with Graphviz, Linux kernel documentation and various other package documentations). A list of the breakages and why: * /usr/share/sgml/docbook/xsl-stylesheets/roundtrip/template.dot seems to be a binary file and thus can't be read. * /usr/share/graphviz/graphs/directed/Latin1.gv uses Latin1 encoding; at the moment graphviz uses the system's locale encoding (or whatever GHC < 6.10 defaults to). * /usr/share/doc/boost-*/html/libs/graph/example/graphviz_test.dot (various boost versions) has subgraphs in edges; graphviz currently can't cope with these. * /usr/src/linux-2.6.33-gentoo-r1/Documentation/blockdev/drbd/drbd-connection-state-overview.dot uses incorrect syntax for the "minlen" attribute (it is meant to be an integer but actually contains a floating point value). The plans for the next release (which I don't plan on even starting for a while) are to focus on improving printing and parsing performance, using a state-based printer and parser (as part of Dot syntax is state-based) and force usage of UTF-8 (via text or utf8-string). -- Ivan Lazar Miljenovic Ivan.Miljenovic(a)gmail.com IvanMiljenovic.wordpress.com

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Why does cabal select base-3.0.3.2 when base-4.2.0.0 is available?
by Bjorn Buckwalter 26 Apr '10

26 Apr '10

Dear all, Why does cabal seem to prefer base-3.0.3.2 over base-4.2.0.0 when installing packages with an unqualified base requirement? Example: $ cabal install -v fad --reinstall [snip] Resolving dependencies... selecting fad-1.0 (hackage) selecting base-3.0.3.2 (installed) and 4.2.0.0 (installed) and discarding syb-0.1.0.0, 0.1.0.1, 0.1.0.2, 0.1.0.3, 0.2 and 0.2.1 [snip] Configuring fad-1.0... Dependency base ==3.0.3.2: using base-3.0.3.2 [snip] [1 of 1] Compiling Numeric.FAD ( Numeric/FAD.hs, dist/build/Numeric/FAD.o ) Numeric/FAD.hs:1:0: Warning: Module `Prelude' is deprecated: You are using the old package `base' version 3.x. Future GHC versions will not support base version 3.x. You should update your code to use the new base version 4.x. [snip] Thanks, Bjorn

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Re: [Haskell-cafe] Broken ghc documentation links
by Ivan Lazar Miljenovic 26 Apr '10

26 Apr '10

"haskell(a)kudling.de" <haskell(a)kudling.de> writes: > While the URL http://www.haskell.org/hoogle/ contains the word "Hoogle", the URL > http://haskell.org/ghc/docs/6.12.1/html/libraries/base-4.2.0.0/Prelude.html… > does not and it does no mention "Hoogle" on the page either. > > How did you determine that the latter is related to Hoogle? Oh, sorry, I misunderstood what you were doing; I thought the actual link you got from Hoogle was wrong (since a lot of people recently have been complaining that Hoogle should now point to the 6.12.2 documentation). In this case, you should talk to GHC maintainers. -- Ivan Lazar Miljenovic Ivan.Miljenovic(a)gmail.com IvanMiljenovic.wordpress.com

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Fwd: Re: [Haskell-cafe] Broken ghc documentation links
by haskell＠kudling.de 26 Apr '10

26 Apr '10

FYI ---------- Ursprüngliche Nachricht ---------- Von: "haskell(a)kudling.de" <haskell(a)kudling.de> An: Ivan Lazar Miljenovic <ivan.miljenovic(a)gmail.com> Cc: Neil Mitchell <ndmitchell(a)gmail.com> Datum: 26. April 2010 um 13:45 Betreff: Re: [Haskell-cafe] Broken ghc documentation links Hi, > So, the problem is that there are broken links _in Hoogle_; have you > thought about contacting the author Neil Mitchell directly? While the URL http://www.haskell.org/hoogle/ contains the word "Hoogle", the URL http://haskell.org/ghc/docs/6.12.1/html/libraries/base-4.2.0.0/Prelude.html… does not and it does no mention "Hoogle" on the page either. How did you determine that the latter is related to Hoogle? Bye, Lnny

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Ada-style ranges
by haskell＠kudling.de 26 Apr '10

26 Apr '10

Hi list, how would you describe Ada's ranges in Haskell's typesystem? http://en.wikibooks.org/wiki/Ada_Programming/Types/range I feel, you can not because this is a runtime property. Bye, Lenny

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Unicode strings and runCommand / runProcess
by John Goerzen 26 Apr '10

26 Apr '10

Here is a very interesting little problem. ghci GHCi, version 6.12.1: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Prelude> :m System.Process Prelude System.Process> runCommand "echo привет" ?@825B This is a minimal test case for a bug reported in HSH at http://github.com/jgoerzen/hsh/issues#issue/1 It is not entirely clear to me what the behavior here should be. It seems inconsistent with the default behavior of System.IO to, apparently, just strip the bits higher than 0xFF. On the other hand, when it's OS commands we're talking about, it's not entirely clear to me if the default should be to encode in UTF-8. There should almost certainly be an *option* controlling this, and perhaps a version of runProcess that accepts ByteStrings. Thoughts? -- John

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London HUG domain expired
by Bayley, Alistair 26 Apr '10

26 Apr '10

> From: glasgow-haskell-users-bounces(a)haskell.org > [mailto:glasgow-haskell-users-bounces@haskell.org] On Behalf > Of Denys Rtveliashvili > > On the side note, is London HUG still active? The website > seems to be down... Looks like the London HUG domain (londonhug.net) registration has expired. Neil Bartlett was the registrant. Neil: do you plan to renew? Alistair ***************************************************************** Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. *****************************************************************

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singleton types
by Günther Schmidt 25 Apr '10

25 Apr '10

Hello, HaskellDB makes extensive use of Singleton Types, both in its original version and the more recent one where it's using HList instead of the legacy implementation. I wonder if it is possible, not considering feasibility for the moment, to implement HaskellDB *without* using Singleton Types. Luke Palmer demonstrates in one blog post replacing type classes with data structures, so I wonder if this could also be applied in this setting. Best regards Günther

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Re: FGL up for adoption
by Louis Wasserman 25 Apr '10

25 Apr '10

I'd be really interested; I have a lot of improvements I'd personally like to make. Louis Wasserman wasserman.louis(a)gmail.com http://profiles.google.com/wasserman.louis

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Announcement: Data.ISO3166_CountryCodes version 0.1
by Jon Fairbairn 25 Apr '10

25 Apr '10

Just uploaded to hackage. Package providing datatype generated from the ISO3166 country code list. This was originally part of my Typeful HTMLs stuff, but I thought it deserved a wider audience. I think anything that uses country codes should use this datatype! As this is my first attempt at using cabal and uploading to hackage, expect errors and omissions. In particular, as I didn't want it to depend on template haskell, the build process generates the module's source file, which means that that file shouldn't be in the tarball. Cabal complains that it's missing if it's not there, so I created an empty .hsc file to shut it up. I'm sure this is not the right way, so I'd be glad to hear what is. -- Jón Fairbairn Jon.Fairbairn(a)cl.cam.ac.uk http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2009-01-31)

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