futhark-0.11.0: An optimising compiler for a functional, array-oriented language.

Safe HaskellNone
LanguageHaskell2010

Futhark.Util

Description

Non-Futhark-specific utilities. If you find yourself writing general functions on generic data structures, consider putting them here.

Sometimes it is also preferable to copy a small function rather than introducing a large dependency. In this case, make sure to note where you got it from (and make sure that the license is compatible).

Synopsis

Documentation

mapAccumLM :: Monad m => (acc -> x -> m (acc, y)) -> acc -> [x] -> m (acc, [y]) Source #

Like mapAccumL, but monadic.

chunk :: Int -> [a] -> [[a]] Source #

chunk n a splits a into n-size-chunks. If the length of a is not divisible by n, the last chunk will have fewer than n elements (but it will never be empty).

chunks :: [Int] -> [a] -> [[a]] Source #

chunks ns a splits a into chunks determined by the elements of ns. It must hold that sum ns == length a, or the resulting list may contain too few chunks, or not all elements of a.

dropAt :: Int -> Int -> [a] -> [a] Source #

dropAt i n drops n elements starting at element i.

takeLast :: Int -> [a] -> [a] Source #

takeLast n l takes the last n elements of l.

dropLast :: Int -> [a] -> [a] Source #

dropLast n l drops the last n elements of l.

mapEither :: (a -> Either b c) -> [a] -> ([b], [c]) Source #

A combination of map and partitionEithers.

maybeNth :: Integral int => int -> [a] -> Maybe a Source #

Return the list element at the given index, if the index is valid.

maybeHead :: [a] -> Maybe a Source #

Return the first element of the list, if it exists.

splitFromEnd :: Int -> [a] -> ([a], [a]) Source #

Like splitAt, but from the end.

splitAt3 :: Int -> Int -> [a] -> ([a], [a], [a]) Source #

Like splitAt, but produces three lists.

splitAt4 :: Int -> Int -> Int -> [a] -> ([a], [a], [a], [a]) Source #

Like splitAt, but produces four lists.

focusNth :: Integral int => int -> [a] -> Maybe ([a], a, [a]) Source #

Return the list element at the given index, if the index is valid, along with the elements before and after.

unixEnvironment :: [(String, String)] Source #

The Unix environment when the Futhark compiler started.

runProgramWithExitCode :: FilePath -> [String] -> String -> IO (Either IOException (ExitCode, String, String)) Source #

Like readProcessWithExitCode, but also wraps exceptions when the indicated binary cannot be launched, or some other exception is thrown.

directoryContents :: FilePath -> IO [FilePath] Source #

Every non-directory file contained in a directory tree.

roundFloat :: Float -> Float Source #

Round a single-precision floating point number correctly.

roundDouble :: Double -> Double Source #

Round a double-precision floating point number correctly.

fromPOSIX :: FilePath -> FilePath Source #

Some bad operating systems do not use forward slash as directory separator - this is where we convert Futhark includes (which always use forward slash) to native paths.

toPOSIX :: FilePath -> FilePath Source #

Turn a POSIX filepath into a filepath for the native system.

trim :: String -> String Source #

Remove leading and trailing whitespace from a string. Not an efficient implementation!

pmapIO :: (a -> IO b) -> [a] -> IO [b] Source #

zEncodeString :: UserString -> EncodedString Source #