reorder repo parameters last

Many functions took the repo as their first parameter. Changing it
consistently to be the last parameter allows doing some useful things with
currying, that reduce boilerplate.

In particular, g <- gitRepo is almost never needed now, instead
use inRepo to run an IO action in the repo, and fromRepo to get
a value from the repo.

This also provides more opportunities to use monadic and applicative
combinators.

1 files changed, 14 insertions, 2 deletions

diff --git a/Annex.hs b/Annex.hs
index 2c6402ac3..501e54c66 100644
--- a/Annex.hs
+++ b/Annex.hs
@@ -17,7 +17,9 @@ module Annex (
 	eval,
 	getState,
 	changeState,
-	gitRepo
+	gitRepo,
+	inRepo,
+	fromRepo,
 ) where
 
 import Control.Monad.IO.Control
@@ -114,6 +116,16 @@ getState = gets
 changeState :: (AnnexState -> AnnexState) -> Annex ()
 changeState = modify
 
-{- Returns the git repository being acted on -}
+{- Returns the annex's git repository. -}
 gitRepo :: Annex Git.Repo
 gitRepo = getState repo
+
+{- Runs an IO action in the annex's git repository. -}
+inRepo :: (Git.Repo -> IO a) -> Annex a
+inRepo a = do
+	g <- gitRepo
+	liftIO $ a g
+
+{- Extracts a value from the annex's git repisitory. -}
+fromRepo :: (Git.Repo -> a) -> Annex a
+fromRepo a = a <$> gitRepo