8ea5f3ff99
Eliminated some dead code. In other cases, exported a currently unused function, since it was a logical part of the API. Of course this improves the API documentation. It may also sometimes let ghc optimize code better, since it can know a function is internal to a module. 364 modules still to go, according to git grep -E 'module [A-Za-z.]+ where'
124 lines
3.4 KiB
Haskell
124 lines
3.4 KiB
Haskell
{- misc utility functions
|
|
-
|
|
- Copyright 2010-2011 Joey Hess <id@joeyh.name>
|
|
-
|
|
- License: BSD-2-clause
|
|
-}
|
|
|
|
{-# OPTIONS_GHC -fno-warn-tabs #-}
|
|
|
|
module Utility.Misc (
|
|
hGetContentsStrict,
|
|
readFileStrict,
|
|
separate,
|
|
firstLine,
|
|
segment,
|
|
segmentDelim,
|
|
massReplace,
|
|
hGetSomeString,
|
|
exitBool,
|
|
|
|
prop_segment_regressionTest,
|
|
) where
|
|
|
|
import System.IO
|
|
import Control.Monad
|
|
import Foreign
|
|
import Data.Char
|
|
import Data.List
|
|
import System.Exit
|
|
import Control.Applicative
|
|
import Prelude
|
|
|
|
{- A version of hgetContents that is not lazy. Ensures file is
|
|
- all read before it gets closed. -}
|
|
hGetContentsStrict :: Handle -> IO String
|
|
hGetContentsStrict = hGetContents >=> \s -> length s `seq` return s
|
|
|
|
{- A version of readFile that is not lazy. -}
|
|
readFileStrict :: FilePath -> IO String
|
|
readFileStrict = readFile >=> \s -> length s `seq` return s
|
|
|
|
{- Like break, but the item matching the condition is not included
|
|
- in the second result list.
|
|
-
|
|
- separate (== ':') "foo:bar" = ("foo", "bar")
|
|
- separate (== ':') "foobar" = ("foobar", "")
|
|
-}
|
|
separate :: (a -> Bool) -> [a] -> ([a], [a])
|
|
separate c l = unbreak $ break c l
|
|
where
|
|
unbreak r@(a, b)
|
|
| null b = r
|
|
| otherwise = (a, tail b)
|
|
|
|
{- Breaks out the first line. -}
|
|
firstLine :: String -> String
|
|
firstLine = takeWhile (/= '\n')
|
|
|
|
{- Splits a list into segments that are delimited by items matching
|
|
- a predicate. (The delimiters are not included in the segments.)
|
|
- Segments may be empty. -}
|
|
segment :: (a -> Bool) -> [a] -> [[a]]
|
|
segment p l = map reverse $ go [] [] l
|
|
where
|
|
go c r [] = reverse $ c:r
|
|
go c r (i:is)
|
|
| p i = go [] (c:r) is
|
|
| otherwise = go (i:c) r is
|
|
|
|
prop_segment_regressionTest :: Bool
|
|
prop_segment_regressionTest = all id
|
|
-- Even an empty list is a segment.
|
|
[ segment (== "--") [] == [[]]
|
|
-- There are two segements in this list, even though the first is empty.
|
|
, segment (== "--") ["--", "foo", "bar"] == [[],["foo","bar"]]
|
|
]
|
|
|
|
{- Includes the delimiters as segments of their own. -}
|
|
segmentDelim :: (a -> Bool) -> [a] -> [[a]]
|
|
segmentDelim p l = map reverse $ go [] [] l
|
|
where
|
|
go c r [] = reverse $ c:r
|
|
go c r (i:is)
|
|
| p i = go [] ([i]:c:r) is
|
|
| otherwise = go (i:c) r is
|
|
|
|
{- Replaces multiple values in a string.
|
|
-
|
|
- Takes care to skip over just-replaced values, so that they are not
|
|
- mangled. For example, massReplace [("foo", "new foo")] does not
|
|
- replace the "new foo" with "new new foo".
|
|
-}
|
|
massReplace :: [(String, String)] -> String -> String
|
|
massReplace vs = go [] vs
|
|
where
|
|
|
|
go acc _ [] = concat $ reverse acc
|
|
go acc [] (c:cs) = go ([c]:acc) vs cs
|
|
go acc ((val, replacement):rest) s
|
|
| val `isPrefixOf` s =
|
|
go (replacement:acc) vs (drop (length val) s)
|
|
| otherwise = go acc rest s
|
|
|
|
{- Wrapper around hGetBufSome that returns a String.
|
|
-
|
|
- The null string is returned on eof, otherwise returns whatever
|
|
- data is currently available to read from the handle, or waits for
|
|
- data to be written to it if none is currently available.
|
|
-
|
|
- Note on encodings: The normal encoding of the Handle is ignored;
|
|
- each byte is converted to a Char. Not unicode clean!
|
|
-}
|
|
hGetSomeString :: Handle -> Int -> IO String
|
|
hGetSomeString h sz = do
|
|
fp <- mallocForeignPtrBytes sz
|
|
len <- withForeignPtr fp $ \buf -> hGetBufSome h buf sz
|
|
map (chr . fromIntegral) <$> withForeignPtr fp (peekbytes len)
|
|
where
|
|
peekbytes :: Int -> Ptr Word8 -> IO [Word8]
|
|
peekbytes len buf = mapM (peekElemOff buf) [0..pred len]
|
|
|
|
exitBool :: Bool -> IO a
|
|
exitBool False = exitFailure
|
|
exitBool True = exitSuccess
|