git-repair (1.20131122) unstable; urgency=low

  * Added test mode, which can be used to randomly corrupt test
    repositories, in reproducible ways, which allows easy
    corruption-driven-development.
  * Improve repair code in the case where the index file is corrupt,
    and this hides other problems.
  * Write a dummy .git/HEAD if the file is missing or corrupt, as
    git otherwise will not treat the repository as a git repo.
  * Improve fsck code to find badly corrupted objects that crash git fsck
    before it can complain about them.
  * Fixed crashes on bad file encodings.
  * Can now run 10000 tests (git-repair --test -n 10000 --force)
    with 0 failures.

# imported from the archive

1 files changed, 69 insertions, 0 deletions

diff --git a/Utility/Monad.hs b/Utility/Monad.hs
new file mode 100644
index 0000000..1ba43c5
--- /dev/null
+++ b/Utility/Monad.hs
@@ -0,0 +1,69 @@
+{- monadic stuff
+ -
+ - Copyright 2010-2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Utility.Monad where
+
+import Data.Maybe
+import Control.Monad
+
+{- Return the first value from a list, if any, satisfying the given
+ - predicate -}
+firstM :: Monad m => (a -> m Bool) -> [a] -> m (Maybe a)
+firstM _ [] = return Nothing
+firstM p (x:xs) = ifM (p x) (return $ Just x , firstM p xs)
+
+{- Runs the action on values from the list until it succeeds, returning
+ - its result. -}
+getM :: Monad m => (a -> m (Maybe b)) -> [a] -> m (Maybe b)
+getM _ [] = return Nothing
+getM p (x:xs) = maybe (getM p xs) (return . Just) =<< p x
+
+{- Returns true if any value in the list satisfies the predicate,
+ - stopping once one is found. -}
+anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool
+anyM p = liftM isJust . firstM p
+
+allM :: Monad m => (a -> m Bool) -> [a] -> m Bool
+allM _ [] = return True
+allM p (x:xs) = p x <&&> allM p xs
+
+{- Runs an action on values from a list until it succeeds. -}
+untilTrue :: Monad m => [a] -> (a -> m Bool) -> m Bool
+untilTrue = flip anyM
+
+{- if with a monadic conditional. -}
+ifM :: Monad m => m Bool -> (m a, m a) -> m a
+ifM cond (thenclause, elseclause) = do
+	c <- cond
+	if c then thenclause else elseclause
+
+{- short-circuiting monadic || -}
+(<||>) :: Monad m => m Bool -> m Bool -> m Bool
+ma <||> mb = ifM ma ( return True , mb )
+
+{- short-circuiting monadic && -}
+(<&&>) :: Monad m => m Bool -> m Bool -> m Bool
+ma <&&> mb = ifM ma ( mb , return False )
+
+{- Same fixity as && and || -}
+infixr 3 <&&>
+infixr 2 <||>
+
+{- Runs an action, passing its value to an observer before returning it. -}
+observe :: Monad m => (a -> m b) -> m a -> m a
+observe observer a = do
+	r <- a
+	_ <- observer r
+	return r
+
+{- b `after` a runs first a, then b, and returns the value of a -}
+after :: Monad m => m b -> m a -> m a
+after = observe . const
+
+{- do nothing -}
+noop :: Monad m => m ()
+noop = return ()