David Fox wrote:
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.
Thanks, that's the most helpful hint. It matches MissingH's use of .Utils modules too. Jean-Marie Gaillourdet wrote:
Personally, I've always been avoiding those grab-bags of functionality like MissingH and other libraries. Not because I think they don't provide anything useful. But, because their level of maintenance is not clear to me. A rather large library of utility functions tends to need many dependencies on other hackage packages. That makes the question of maintenance even more important.
It's not clear to me either. I used MissingH starting out because I personally know and trust John and/or he cowrote RWH. Don't know that I would have otherwise. (And I only use Data.String.Utils, System.Cmd.Utils, and Data.Bits.Utils from it.)
As others have pointed out some of your functions may already exist in some widely used package. And other might be easy to be replaced by some idiom. Don't underestimate the depth of Haskell and it's well thought libraries. I am regularly amazed by finding some new way to combine seemingly trivial functions to do some non-trivial task. Every time that happens I can remove some of my utility functions.
Well, this is certianly true, on the other hand then you end up with a pattern of repeatedly combining some trivial functions in a certian way, and it then makes sense to formalize that. It's better to have `fromMaybe` than to repeatedly use `id` with `maybe`. Tristan Ravitch wrote:
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)
IfElse (http://hackage.haskell.org/packages/archive/IfElse/0.85/doc/html/Control-Mon...) has a few of these.
whenM is in a dozen packages, the others fewer but scattered here and there. I also found >>? and >>! somewhere on hackage once but not sure where.
Various path manipulation functions such as: absPath :: FilePath -> IO FilePath
Is this different from canonicalizePath in directory?
Yes; it doesn't require the path to exist.
Other stuff:
separate :: (a -> Bool) -> [a] -> ([a], [a])
Is this partition from Data.List?
No; it's like break but does not include the separating character in the snd list.
format :: Format -> Variables -> String
This looks like it might be similar to HStringTemplate
This particular format allows for things like "${foo} ${bar;10} ${baz;-10}\n" so it's sort of printf like, but not entirely.
withTempFile :: Template -> (FilePath -> Handle -> IO a) -> IO a
temporary (http://hackage.haskell.org/packages/archive/temporary/1.1.2.3/doc/html/Syste...) has a few variants of this one
Indeed, however all its functions can fail if getTemporaryDirectory fails; this one puts the temp file in "." in that case. Simon Hengel wrote:
headMaybe :: [a] -> Maybe a
Is this the same as Data.Maybe.maybeToList?
Rather listToMaybe.. it is the same as that in fact. Though I also have a lastMaybe that does not have an equivilant in Data.Maybe.
readMaybe :: Read a => String -> Maybe a
This has been added to base recently [1].
Great! Although there are multiple ways to choose to implement this. I found it useful to make it succeed even if not all the string was consumed, or when there are multiple valid results. I've renamed mine readish. -- eee shy jo