This commit is contained in:
Joey Hess 2012-01-21 02:24:12 -04:00
parent eb9001044f
commit 183bdacca2
4 changed files with 12 additions and 8 deletions

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@ -37,9 +37,11 @@ data Frag = Const String | Var String Justify
data Justify = LeftJustified Int | RightJustified Int | UnJustified data Justify = LeftJustified Int | RightJustified Int | UnJustified
deriving (Show) deriving (Show)
type Variables = M.Map String String
{- Expands a Format using some variables, generating a formatted string. {- Expands a Format using some variables, generating a formatted string.
- This can be repeatedly called, efficiently. -} - This can be repeatedly called, efficiently. -}
format :: Format -> M.Map String String -> String format :: Format -> Variables -> String
format f vars = concatMap expand f format f vars = concatMap expand f
where where
expand (Const s) = s expand (Const s) = s

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@ -12,7 +12,7 @@ import Control.Monad (liftM)
{- Return the first value from a list, if any, satisfying the given {- Return the first value from a list, if any, satisfying the given
- predicate -} - predicate -}
firstM :: (Monad m) => (a -> m Bool) -> [a] -> m (Maybe a) firstM :: Monad m => (a -> m Bool) -> [a] -> m (Maybe a)
firstM _ [] = return Nothing firstM _ [] = return Nothing
firstM p (x:xs) = do firstM p (x:xs) = do
q <- p x q <- p x
@ -22,20 +22,20 @@ firstM p (x:xs) = do
{- Returns true if any value in the list satisfies the predicate, {- Returns true if any value in the list satisfies the predicate,
- stopping once one is found. -} - stopping once one is found. -}
anyM :: (Monad m) => (a -> m Bool) -> [a] -> m Bool anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool
anyM p = liftM isJust . firstM p anyM p = liftM isJust . firstM p
{- Runs an action on values from a list until it succeeds. -} {- Runs an action on values from a list until it succeeds. -}
untilTrue :: (Monad m) => [a] -> (a -> m Bool) -> m Bool untilTrue :: Monad m => [a] -> (a -> m Bool) -> m Bool
untilTrue = flip anyM untilTrue = flip anyM
{- Runs an action, passing its value to an observer before returning it. -} {- Runs an action, passing its value to an observer before returning it. -}
observe :: (Monad m) => (a -> m b) -> m a -> m a observe :: Monad m => (a -> m b) -> m a -> m a
observe observer a = do observe observer a = do
r <- a r <- a
_ <- observer r _ <- observer r
return r return r
{- b `after` a runs first a, then b, and returns the value of a -} {- b `after` a runs first a, then b, and returns the value of a -}
after :: (Monad m) => m b -> m a -> m a after :: Monad m => m b -> m a -> m a
after = observe . const after = observe . const

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@ -37,7 +37,7 @@ last = Prelude.last
- Ignores leading/trailing whitespace, and throws away any trailing - Ignores leading/trailing whitespace, and throws away any trailing
- text after the part that can be read. - text after the part that can be read.
-} -}
readMaybe :: (Read a) => String -> Maybe a readMaybe :: Read a => String -> Maybe a
readMaybe s = case reads s of readMaybe s = case reads s of
((x,_):_) -> Just x ((x,_):_) -> Just x
_ -> Nothing _ -> Nothing

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@ -26,8 +26,10 @@ viaTmp a file content = do
a tmpfile content a tmpfile content
renameFile tmpfile file renameFile tmpfile file
type Template = String
{- Runs an action with a temp file, then removes the file. -} {- Runs an action with a temp file, then removes the file. -}
withTempFile :: String -> (FilePath -> Handle -> IO a) -> IO a withTempFile :: Template -> (FilePath -> Handle -> IO a) -> IO a
withTempFile template a = bracket create remove use withTempFile template a = bracket create remove use
where where
create = do create = do