Safe Haskell | None |
---|---|
Language | Haskell98 |
Utitlity functions on lists.
- mhead :: [a] -> Maybe a
- uncons :: [a] -> Maybe (a, [a])
- mcons :: Maybe a -> [a] -> [a]
- initLast :: [a] -> Maybe ([a], a)
- (!!!) :: [a] -> Int -> Maybe a
- downFrom :: Integral a => a -> [a]
- updateLast :: (a -> a) -> [a] -> [a]
- mapEither :: (a -> Either b c) -> [a] -> ([b], [c])
- deal :: (a -> Either b c) -> a -> ([b], [c]) -> ([b], [c])
- takeWhileJust :: (a -> Maybe b) -> [a] -> [b]
- spanJust :: (a -> Maybe b) -> [a] -> ([b], [a])
- partitionMaybe :: (a -> Maybe b) -> [a] -> ([a], [b])
- isSublistOf :: Eq a => [a] -> [a] -> Bool
- type Prefix a = [a]
- type Suffix a = [a]
- maybePrefixMatch :: Eq a => Prefix a -> [a] -> Maybe (Suffix a)
- data PreOrSuffix a
- preOrSuffix :: Eq a => [a] -> [a] -> PreOrSuffix a
- wordsBy :: (a -> Bool) -> [a] -> [[a]]
- chop :: Int -> [a] -> [[a]]
- holes :: [a] -> [(a, [a])]
- sorted :: Ord a => [a] -> Bool
- distinct :: Eq a => [a] -> Bool
- fastDistinct :: Ord a => [a] -> Bool
- prop_distinct_fastDistinct :: [Integer] -> Bool
- allEqual :: Eq a => [a] -> Bool
- groupBy' :: (a -> a -> Bool) -> [a] -> [[a]]
- prop_groupBy' :: (Bool -> Bool -> Bool) -> [Bool] -> Property
- groupOn :: Ord b => (a -> b) -> [a] -> [[a]]
- splitExactlyAt :: Integral n => n -> [a] -> Maybe ([a], [a])
- extractNthElement' :: Integral i => i -> [a] -> ([a], a, [a])
- extractNthElement :: Integral i => i -> [a] -> (a, [a])
- prop_extractNthElement :: Integer -> [Integer] -> Property
- genericElemIndex :: (Eq a, Integral i) => a -> [a] -> Maybe i
- prop_genericElemIndex :: Integer -> [Integer] -> Property
- zipWith' :: (a -> b -> c) -> [a] -> [b] -> [c]
- prop_zipWith' :: (Integer -> Integer -> Integer) -> Property
- uniqBy :: Ord b => (a -> b) -> [a] -> [a]
- prop_uniqBy :: [Integer] -> Bool
- tests :: IO Bool
Documentation
updateLast :: (a -> a) -> [a] -> [a] Source
Update the last element of a list, if it exists
mapEither :: (a -> Either b c) -> [a] -> ([b], [c]) Source
A generalized version of partition
.
(Cf. mapMaybe
vs. filter
).
takeWhileJust :: (a -> Maybe b) -> [a] -> [b] Source
A generalized version of takeWhile
.
(Cf. mapMaybe
vs. filter
).
partitionMaybe :: (a -> Maybe b) -> [a] -> ([a], [b]) Source
isSublistOf :: Eq a => [a] -> [a] -> Bool Source
Sublist relation.
maybePrefixMatch :: Eq a => Prefix a -> [a] -> Maybe (Suffix a) Source
Check if a list has a given prefix. If so, return the list minus the prefix.
data PreOrSuffix a Source
Result of preOrSuffix
.
preOrSuffix :: Eq a => [a] -> [a] -> PreOrSuffix a Source
Compare lists with respect to prefix partial order.
wordsBy :: (a -> Bool) -> [a] -> [[a]] Source
Split a list into sublists. Generalisation of the prelude function
words
.
words xs == wordsBy isSpace xs
sorted :: Ord a => [a] -> Bool Source
Check whether a list is sorted.
Assumes that the Ord
instance implements a partial order.
distinct :: Eq a => [a] -> Bool Source
Check whether all elements in a list are distinct from each
other. Assumes that the Eq
instance stands for an equivalence
relation.
fastDistinct :: Ord a => [a] -> Bool Source
prop_distinct_fastDistinct :: [Integer] -> Bool Source
allEqual :: Eq a => [a] -> Bool Source
Checks if all the elements in the list are equal. Assumes that
the Eq
instance stands for an equivalence relation.
groupBy' :: (a -> a -> Bool) -> [a] -> [[a]] Source
A variant of groupBy
which applies the predicate to consecutive
pairs.
splitExactlyAt :: Integral n => n -> [a] -> Maybe ([a], [a]) Source
splitExactlyAt n xs = Just (ys, zs)
iff xs = ys ++ zs
and genericLength ys = n
.
extractNthElement' :: Integral i => i -> [a] -> ([a], a, [a]) Source
gives the extractNthElement
n xsn
-th element in xs
(counting from 0), plus the remaining elements (preserving order).
extractNthElement :: Integral i => i -> [a] -> (a, [a]) Source
prop_extractNthElement :: Integer -> [Integer] -> Property Source
genericElemIndex :: (Eq a, Integral i) => a -> [a] -> Maybe i Source
A generalised variant of elemIndex
.
prop_genericElemIndex :: Integer -> [Integer] -> Property Source
uniqBy :: Ord b => (a -> b) -> [a] -> [a] Source
Efficient version of nub that sorts the list first. The tag function is assumed to be cheap. If it isn't pair up the elements with their tags and call uniqBy fst (or snd).
prop_uniqBy :: [Integer] -> Bool Source