Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
branch: master
Fetching contributors…

Cannot retrieve contributors at this time

181 lines (119 sloc) 4.818 kB
{-# LANGUAGE TupleSections, PatternGuards #-}
module Utilities (
module IdSupply,
module Utilities,
module Control.Arrow,
module Control.Exception,
module Control.Monad,
module Debug.Trace,
module Text.PrettyPrint.HughesPJClass
) where
import IdSupply
import Control.Arrow (first, second, (***), (&&&))
import Control.Exception (assert)
import Control.Monad
import qualified Data.Set as S
import Debug.Trace
import Text.PrettyPrint.HughesPJClass hiding (render)
import System.IO.Unsafe (unsafePerformIO)
instance Pretty a => Pretty (S.Set a) where
pPrint xs = char '{' <> hsep (punctuate (char ',') (map pPrint $ S.toList xs)) <> char '}'
{-# NOINLINE reduceIdSupply #-}
reduceIdSupply :: IdSupply
reduceIdSupply = unsafePerformIO $ initIdSupply 'u'
{-# NOINLINE normaliseIdSupply #-}
normaliseIdSupply :: IdSupply
normaliseIdSupply = unsafePerformIO $ initIdSupply 'n'
stepIdSupply :: IdSupply -> (IdSupply, Id)
stepIdSupply = second idFromSupply . splitIdSupply
data Train a b = Wagon a (Train a b)
| Caboose b
appPrec, opPrec, noPrec :: Rational
appPrec = 2 -- Argument of a function application
opPrec = 1 -- Argument of an infix operator
noPrec = 0 -- Others
normalLevel, haskellLevel :: PrettyLevel
normalLevel = PrettyLevel 0
haskellLevel = PrettyLevel 1
angles, coangles :: Doc -> Doc
angles d = char '<' <> d <> char '>'
coangles d = char '>' <> d <> char '<'
pPrintPrec' :: Pretty a => a -> PrettyLevel -> Rational -> Doc
pPrintPrec' x level prec = pPrintPrec level prec x
-- NB: this render function is exported instead of the one from the library
render :: Doc -> String
render = renderStyle (style { lineLength = 120 })
pPrintRender :: Pretty a => a -> String
pPrintRender = render . pPrint
traceRender :: Pretty a => a -> b -> b
traceRender x = trace (pPrintRender x)
removeOnes :: [a] -> [[a]]
removeOnes [] = []
removeOnes (x:xs) = xs : map (x:) (removeOnes xs)
instance (Pretty a, Pretty b, Pretty c, Pretty d,
Pretty e, Pretty f, Pretty g, Pretty h,
Pretty i, Pretty j, Pretty k, Pretty l,
Pretty m, Pretty n, Pretty o) => Pretty (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) where
pPrint (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)
= pPrintTuple [pPrint a, pPrint b, pPrint c, pPrint d,
pPrint e, pPrint f, pPrint g, pPrint h,
pPrint i, pPrint j, pPrint k, pPrint l,
pPrint m, pPrint n, pPrint o]
pPrintTuple :: [Doc] -> Doc
pPrintTuple ds = parens $ fsep $ punctuate comma ds
newtype PrettyFunction = PrettyFunction (PrettyLevel -> Rational -> Doc)
instance Pretty PrettyFunction where
pPrintPrec level prec (PrettyFunction f) = f level prec
asPrettyFunction :: Pretty a => a -> PrettyFunction
asPrettyFunction = PrettyFunction . pPrintPrec'
fst3 :: (a, b, c) -> a
fst3 (a, _, _) = a
snd3 :: (a, b, c) -> b
snd3 (_, b, _) = b
thd3 :: (a, b, c) -> c
thd3 (_, _, c) = c
first3 :: (a -> d) -> (a, b, c) -> (d, b, c)
first3 f (a, b, c) = (f a, b, c)
second3 :: (b -> d) -> (a, b, c) -> (a, d, c)
second3 f (a, b, c) = (a, f b, c)
third3 :: (c -> d) -> (a, b, c) -> (a, b, d)
third3 f (a, b, c) = (a, b, f c)
second4 :: (b -> e) -> (a, b, c, d) -> (a, e, c, d)
second4 f (a, b, c, d) = (a, f b, c, d)
third4 :: (c -> e) -> (a, b, c, d) -> (a, b, e, d)
third4 f (a, b, c, d) = (a, b, f c, d)
secondM :: Monad m => (b -> m c) -> (a, b) -> m (a, c)
secondM f (a, b) = liftM (a,) $ f b
uncurry3 :: (a -> b -> c -> d) -> (a, b, c) -> d
uncurry3 f (a, b, c) = f a b c
splitBy :: [b] -> [a] -> ([a], [a])
splitBy [] xs = ([], xs)
splitBy (_:ys) (x:xs) = first (x:) $ splitBy ys xs
splitManyBy :: [[b]] -> [a] -> [[a]]
splitManyBy [] xs = [xs]
splitManyBy (ys:yss) xs = case splitBy ys xs of (xs1, xs2) -> xs1 : splitManyBy yss xs2
splitAtRev :: Int -> [a] -> ([a], [a])
splitAtRev n xs = case splitAt n (reverse xs) of (xs1, xs2) -> (reverse xs2, reverse xs1)
takeFirst :: (a -> Bool) -> [a] -> (Maybe a, [a])
takeFirst p = takeFirstJust (\x -> guard (p x) >> return x)
takeFirstJust :: (a -> Maybe b) -> [a] -> (Maybe b, [a])
takeFirstJust _ [] = (Nothing, [])
takeFirstJust p (x:xs)
| Just y <- p x = (Just y, xs)
| otherwise = second (x:) $ takeFirstJust p xs
expectJust :: String -> Maybe a -> a
expectJust _ (Just x) = x
expectJust s Nothing = error $ "expectJust: " ++ s
safeFromLeft :: Either a b -> Maybe a
safeFromLeft (Left x) = Just x
safeFromLeft _ = Nothing
safeHead :: [a] -> Maybe a
safeHead [] = Nothing
safeHead (x:_) = Just x
expectHead :: String -> [a] -> a
expectHead s = expectJust s . safeHead
fixpoint :: Eq a => (a -> a) -> a -> a
fixpoint f x
| x' == x = x
| otherwise = fixpoint f x'
where x' = f x
Jump to Line
Something went wrong with that request. Please try again.