August 2006 - Libraries

My documentation of System.Posix.Files
by Johan Tibell 10 Aug '06

10 Aug '06

I've started to write some docs for System.Posix.Files but before I finish that and move on to other packages in System.Posix.* it would be great with some feedback on style (and grammar/spelling of course, English is my second language). http://www.itstud.chalmers.se/~larssont/docs/System-Posix-Files.html * Currently most of the POSIX docs are rather incomplete and are in the spirit of "read the man pages". Often a function's documentation states what C function is called and very little beyond that. The man pages contains a wealth of information but: - Everyone doesn't know C (hopefully Haskell is their first language ;) ) - Everyone might not have them - It takes longer time if you have to go and look in the man pages - There might be subtle differences + They are likely to contain a more in depth information than my documentation of the library ever will! Perhaps I could still annotate each function with something like: NOTE: Uses the POSIX system call stat. Or something like that. Perhaps put a mapping of functions to C calls in the module description. * Perhaps I should put a general description of terms (symbolic links, everything is a file, etc.) in the module description? * Lots of error conditions are undocumented. I added some references to a function called throwErrnoIfMinus1_ which lives in System.Posix.Error. It is currently undocumented and frankly it looks like something that "should" be an internal function. Perhaps I could just mention which computations might throw an IOError? Cheers, Johan

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cabal (./Setup.hs) options
by Conrad Parker 09 Aug '06

09 Aug '06

Hi, I like Cabal. There are a few things that I'm used to from autotools which I can't seem to find: dry-runs, uninstall and a "make distcheck" equivalent. Here's my wishlist (ie. stuff I wish someone, possibly me, would hack on ;-) Are the following planned, possible, far-fetched? ./Setup.hs -n, --dry-run For any command, does not actually do anything (build, install, modify the filesystem), but prints the steps that would be executed (ghc commandlines, install locations etc.) uninstall Removes all files and directories created by install sdist-test 1. runs sdist 2. unpacks the resulting tarball 3. runs configure --prefix=_inst build install (into given _inst) test uninstall 4. Checks that no files remain in _inst 5. Cleans up the source tmpdir 6. If all the above succeed, prints a message saying the tarball is ready for distribution cheers, Conrad.

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darcs patch for fgl - Array import-fix
by Esa Ilari Vuokko 09 Aug '06

09 Aug '06

Hi, attached is a patch that allows fgl to compile after the recent Array-changes in base. I don't know if semantics are correct, but atleast it seems to build now. Best regards, --Esa New patches: [Remove now unneccesary hiding Data.Array.IO.indices Esa Ilari Vuokko <ei(a)vuokko.info>**20060809144302] { hunk ./Data/Graph/Inductive/Monad/IOArray.hs 16 -import Data.Array.IO hiding (indices) +import Data.Array.IO } Context: [Silence warnings. Ian Lynagh <igloo(a)earth.li>**20060730164944] [Remove a variable shadowing warning Ian Lynagh <igloo(a)earth.li>**20060730163933] [Version June 2006 Martin Erwig <erwig(a)eecs.oregonstate.edu>**20060718181211] [[project @ 2006-01-18 10:54:19 by simonmar] simonmar**20060118105419 Stop shadowing a variable (darcs patch from Ian Lynagh) ] [TAG Initial conversion from CVS complete John Goerzen <jgoerzen(a)complete.org>**20060112154129] Patch bundle hash: 8642b9c82dd2177887f7dfc84036d669ff94a27b

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System.Posix.Process.executeFile question
by Frederik Eaton 09 Aug '06

09 Aug '06

Hi, I'm wondering what the second argument to 'executeFile' is. It's not clear from the documentation. http://www.haskell.org/ghc/docs/latest/html/libraries/unix/System-Posix-Pro… Also, it seems the documentation source is being parsed incorrectly. This is what it looks like to me: executeFile :: FilePath -> Bool -> [String] -> Maybe [(String, String)] -> IO () literal>executeFile cmd args env</literal calls one of the function>execv*</function family, depending on whether or not the current PATH is to be searched for the command, and whether or not an environment is provided to supersede the process's current environment. The basename (leading directory names suppressed) of the command is passed to function>execv*</function> as <varname>arg[0]</varname; the argument list passed to function>executeFile</function therefore begins with varname>arg[1]</varname Thanks! Frederik -- http://ofb.net/~frederik/

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ANN: TextRegexLazy-0.66 devel release
by Chris Kuklewicz 08 Aug '06

08 Aug '06

(when (compilesOk) (announce newVersion)) This is a development release announcement of "TextRegexLazy" The "TextRegexLazy" package is dead. Long Live [regex-base -- interfaces ,regex-compat -- replace Text.Regex ,regex-posix -- PosixRE backend ,regex-pcre -- PCRE backend ,regex-parsec -- My lazy Haskell backend ,regex-dfa -- DFA based on modified CTKLight (LGPL) ] Note: Everything is BSD licensed except the regex-dfa engine which is LGPL. The darcs repository at http://evenmere.org/~chrisk/trl/head/ has the new version. The regex-compat package is a single Text.Regex.New module that uses regex-posix to replace Text.Regex (I cut and pasted from the Text.Regex module and re-implemented some of the functions). The old Text.Regex.Posix module is bypassed (so it could be removed in the future). Changing the dependency to a different backend is as simply as changing the import statement. Changing from String to ByteString would be a simple search-and-replace (and import Data.ByteString). The regex-posix package does not have a personal copy of the posix regex library like the copy GHC brings to Windows: http://darcs.haskell.org/packages/base/cbits/regex/ If someone can get regex-posix working on Windows, then [regex-base,regex-posix,regex-compat] will be functionally ready to be included along with GHC. TODO: * Much Haddock fixing for the new module hierarchy * Point the test cases at the new packages * Benchmark -- Chris Kuklewicz

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ANN: TextRegexLazy-0.56, (=~) and (=~~) are here
by Chris Kuklewicz 02 Aug '06

02 Aug '06

Announcing: TextRegexLazy version 0.56 Where: Tarball from http://sourceforge.net/projects/lazy-regex darcs get --partial [--tag=0.56] http://evenmere.org/~chrisk/trl/stable/ License : BSD, except for DFAEngine.hs which is LGPL (derived from CTK light) Development/unstable version is at: darcs get [--partial] http://evenmere.org/~chrisk/trl/devel/ This is the version that has eaten John Meacham's JRegex library and survived to become strong. Thanks John! It now compiles against the posix regexp provided by the c library and the pcre library, in addition to the "full lazy" and the "DFA" backends. All 4 backends can accept regular expressions given as String and as ByteString. All 4 backends can run regular expressions against String and ByteString. In particular, the PosixRE and PCRE can run very efficiently against ByteString. (Though the input for the PosixRE needs to end in a \NUL character for efficiency). So there are 4*2*2 = 16 ways to use to provide input to this library. And the RegexContext class has at least 11 instances that both (=~) and (=~~) can target. So that is 4*2*2*11*2 = 352 things you can do with this library! Get your copy today! To run with cabal before 1.1.4 you will need to comment out the "Extra-Source-Files:" line in the TextRegexLazy.cabal file. The Example.hs file: > {-# OPTIONS_GHC -fglasgow-exts #-} > import Text.Regex.Lazy > import Text.Regex.Full((=~),(=~~)) -- or DFA or PCRE or PosixRE > > main = let b :: Bool > b = ("abaca" =~ "(.)a") > c :: [MatchArray] > c = ("abaca" =~ "(.)a") > d :: Maybe (String,String,String,[String]) > d = ("abaca" =~~ "(.)a") > in do print b > print c > print d This produces: > True > [array (0,1) [(0,(1,2)),(1,(1,1))],array (0,1) [(0,(3,2)),(1,(3,1))]] > Just ("a","ba","ca",["b"]) You can also use makeRegex and makeRegexOpts to compile and save a regular expression which will be used multiple times. Each of the 4 backends has a separate "Regex" data type with its own option types. For low level access, the WrapPCRE and WrapPosix modules expose a typesafe layer around the c libraries. You can query the "getVersion :: Maybe String" to see if the have been compiled into the library. It may be possible to use WrapPCRE and the UTF8 option flags to do unicode regex matching with PCRE. ( The Full and DFA backends use the Haskell unicode Char already ). Adding new types to String/ByteString is a matter of adding instances to the existing classes. Feedback and comments of any length is welcome. -- Chris Kuklewicz

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darcs patch: Remove a variable shadowing warning (and 1 more)
by Ian Lynagh 01 Aug '06

01 Aug '06

Sun Jul 30 17:39:33 BST 2006 Ian Lynagh <igloo(a)earth.li> * Remove a variable shadowing warning Sun Jul 30 17:49:44 BST 2006 Ian Lynagh <igloo(a)earth.li> * Silence warnings.

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