On 2012-01-21 16.20.25 -0400, Joey Hess wrote:

My problem now is that as I start new projects, I want to have my haskell utility functions available, and copying them around is not ideal. So, put them on hackage. But where, exactly?

Instead of putting all of them in one package, how about you group them into multiple relevant packages. That way we can search for them more easily, have smaller, more meaningful imports, and so on. Sometimes they may make sense as pull requests against other packages, instead.

headMaybe :: [a] -> Maybe a

Is this the same as Data.Maybe.maybeToList?

readMaybe :: Read a => String -> Maybe a

This has been added to base recently [1]. Cheers, Simon [1] https://github.com/ghc/packages-base/commit/0e1a02b96cfd03b8488e3ff4ce232466...

I try to create a workflow for this sort of thing. I create a package with a name like set-extra, with one module Data.Set.Extra and an alternative Data.Set module that exports both the old Data.Set and the symbols in Data.Set.Extra. Then I email the maintainers of the Containers package with a suggestion. After a while I upload set-extra to hackage if I need to use set-extra in another hackage package. On Sat, Jan 21, 2012 at 12:20 PM, Joey Hess wrote:

I'm finding a rather unusual problem as I write haskell..

Unlike every other language I've used, large portions of my haskell code are turning out to be general-purpose, reusable code. Fully 20% of the haskell code I've written for git-annex is general purpose. Now, I came out of a decade of perl with maybe 1% reusable code. So I'm sure this is a credit to haskell, and not to me.

My problem now is that as I start new projects, I want to have my haskell utility functions available, and copying them around is not ideal. So, put them on hackage. But where, exactly? It already has several grab bag utility libraries. The only one with much traction is MissingH. Using the others makes a program have an unusual dependency, which while only a cabal install away, would make work for distributions that want to package the program. I've ruled out using a couple on that basis. Doesn't encourage me to add another one.

My 2000+ lines of reusable code are a grab-bag of generic utility functions. Looking them over (see Appendix), I could try to get portions into existing libraries on hackage, but it's unlikely I'd find a home for most of them, so I'm still left with this problem of what to do.

I wonder if the model used for xmonad-contrib, of a big library package, that is very open to additions from contributors, would be helpful here?

John, any interest in moving MissingH in this direction? I get the impression it's not otherwise changing much lately, and parts of it are becoming naturally obsolete, maybe this could inject some life into it. Any other thoughts you have on grab-bag utility libraries on hackage also appreciated.

----

Appendix: A sample of a a few of the better functions from my utility library.

 Some quite generic monadic control functions, few of them truely unique:

 whenM :: Monad m => m Bool -> m () -> m ()   -- also >>?  unlessM :: Monad m => m Bool -> m () -> m () -- also >>!  firstM :: Monad m => (a -> m Bool) -> [a] -> m (Maybe a)

 A module that exports functions conflicting with partial  functions in the Prelude, to avoid them being accidentially  used. And provides some alternatives (which overlap somewhat with Safe):

 headMaybe :: [a] -> Maybe a  readMaybe :: Read a => String -> Maybe a  beginning :: [a] -> [a]

 Various path manipulation functions such as:

 dirContains :: FilePath -> FilePath -> Bool  dotfile :: FilePath -> Bool  absPath :: FilePath -> IO FilePath

 Other stuff:

 separate :: (a -> Bool) -> [a] -> ([a], [a])  catchMaybeIO :: IO a -> IO (Maybe a)  readSize :: [Unit] -> String -> Maybe ByteSize -- parses "100 kb" etc  format :: Format -> Variables -> String  findPubKeys :: String -> IO GpgKeyIds  boolSystem :: FilePath -> [CommandParam] -> IO Bool  withTempFile :: Template -> (FilePath -> Handle -> IO a) -> IO a

-- see shy jo

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Hi Joey, Apologies for such a late reply. I don't know if others have replied on -cafe; it has become too high-volume for me to follow of late. There are several options. MissingH is one. I have accepted patches there for a long time. Another is that now that Hackage/Cabal foster easy inclusion of small packages, you might want to roll your own. (Occasionally I have hesitation about drive-by commits to MissingH because I get asked to support the code later at times.) -- John On 01/21/2012 02:20 PM, Joey Hess wrote:

I'm finding a rather unusual problem as I write haskell..

Unlike every other language I've used, large portions of my haskell code are turning out to be general-purpose, reusable code. Fully 20% of the haskell code I've written for git-annex is general purpose. Now, I came out of a decade of perl with maybe 1% reusable code. So I'm sure this is a credit to haskell, and not to me.

My problem now is that as I start new projects, I want to have my haskell utility functions available, and copying them around is not ideal. So, put them on hackage. But where, exactly? It already has several grab bag utility libraries. The only one with much traction is MissingH. Using the others makes a program have an unusual dependency, which while only a cabal install away, would make work for distributions that want to package the program. I've ruled out using a couple on that basis. Doesn't encourage me to add another one.

My 2000+ lines of reusable code are a grab-bag of generic utility functions. Looking them over (see Appendix), I could try to get portions into existing libraries on hackage, but it's unlikely I'd find a home for most of them, so I'm still left with this problem of what to do.

I wonder if the model used for xmonad-contrib, of a big library package, that is very open to additions from contributors, would be helpful here?

John, any interest in moving MissingH in this direction? I get the impression it's not otherwise changing much lately, and parts of it are becoming naturally obsolete, maybe this could inject some life into it. Any other thoughts you have on grab-bag utility libraries on hackage also appreciated.

----

Appendix: A sample of a a few of the better functions from my utility library.

Some quite generic monadic control functions, few of them truely unique:

whenM :: Monad m => m Bool -> m () -> m () -- also>>? unlessM :: Monad m => m Bool -> m () -> m () -- also>>! firstM :: Monad m => (a -> m Bool) -> [a] -> m (Maybe a)

A module that exports functions conflicting with partial functions in the Prelude, to avoid them being accidentially used. And provides some alternatives (which overlap somewhat with Safe):

headMaybe :: [a] -> Maybe a readMaybe :: Read a => String -> Maybe a beginning :: [a] -> [a]

Various path manipulation functions such as:

dirContains :: FilePath -> FilePath -> Bool dotfile :: FilePath -> Bool absPath :: FilePath -> IO FilePath

Other stuff:

separate :: (a -> Bool) -> [a] -> ([a], [a]) catchMaybeIO :: IO a -> IO (Maybe a) readSize :: [Unit] -> String -> Maybe ByteSize -- parses "100 kb" etc format :: Format -> Variables -> String findPubKeys :: String -> IO GpgKeyIds boolSystem :: FilePath -> [CommandParam] -> IO Bool withTempFile :: Template -> (FilePath -> Handle -> IO a) -> IO a