hledger/Utils.hs

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module Utils (
module Utils,
module Data.List,
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module Data.Tree,
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module Debug.Trace,
module Text.Printf,
module Text.Regex,
quickCheck,
)
where
import System.Directory
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import Data.List
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import Data.Tree
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import Debug.Trace
import Test.QuickCheck (quickCheck)
import Text.Printf
import Text.Regex
splitAtElement :: Eq a => a -> [a] -> [[a]]
splitAtElement e l =
case dropWhile (e==) l of
[] -> []
l' -> first : splitAtElement e rest
where
(first,rest) = break (e==) l'
-- courtesy of allberry_b
tildeExpand :: FilePath -> IO FilePath
tildeExpand ('~':[]) = getHomeDirectory
tildeExpand ('~':'/':xs) = getHomeDirectory >>= return . (++ ('/':xs))
-- ~name, requires -fvia-C or ghc 6.8
--import System.Posix.User
-- tildeExpand ('~':xs) = do let (user, path) = span (/= '/') xs
-- pw <- getUserEntryForName user
-- return (homeDirectory pw ++ path)
tildeExpand xs = return xs
-- tree tools
root = rootLabel
branches = subForest
-- apply f to all tree nodes
treemap :: (a -> b) -> Tree a -> Tree b
treemap f t = Node (f $ root t) (map (treemap f) $ branches t)
-- remove all subtrees whose nodes do not fulfill predicate
treefilter :: (a -> Bool) -> Tree a -> Tree a
treefilter f t = Node
(root t)
(map (treefilter f) $ filter (treeany f) $ branches t)
-- is predicate true in any node of tree ?
treeany :: (a -> Bool) -> Tree a -> Bool
treeany f t = (f $ root t) || (any (treeany f) $ branches t)
-- treedrop -- remove the leaves which do fulfill predicate.
-- treedropall -- do this repeatedly.