| Safe Haskell | Safe-Inferred |
|---|---|
| Language | Haskell2010 |
Fcf.Data.List
Description
Lists.
See also Fcf.Class.Foldable for additional functions.
Synopsis
- data (++) :: [a] -> [a] -> Exp [a]
- data Head :: [a] -> Exp (Maybe a)
- data Last :: [a] -> Exp (Maybe a)
- data Tail :: [a] -> Exp (Maybe [a])
- data Cons :: a -> [a] -> Exp [a]
- data Snoc :: [a] -> a -> Exp [a]
- data Cons2 :: (a, b) -> ([a], [b]) -> Exp ([a], [b])
- data Init :: [a] -> Exp (Maybe [a])
- data Null :: [a] -> Exp Bool
- data Length :: [a] -> Exp Nat
- data Reverse :: [a] -> Exp [a]
- data Intersperse :: a -> [a] -> Exp [a]
- data Intercalate :: [a] -> [[a]] -> Exp [a]
- data Foldr :: (a -> b -> Exp b) -> b -> t a -> Exp b
- data UnList :: b -> (a -> b -> Exp b) -> [a] -> Exp b
- data Concat :: t m -> Exp m
- data ConcatMap :: (a -> Exp [b]) -> t a -> Exp [b]
- data Unfoldr :: (b -> Exp (Maybe (a, b))) -> b -> Exp [a]
- data Replicate :: Nat -> a -> Exp [a]
- data Take :: Nat -> [a] -> Exp [a]
- data Drop :: Nat -> [a] -> Exp [a]
- data TakeWhile :: (a -> Exp Bool) -> [a] -> Exp [a]
- data DropWhile :: (a -> Exp Bool) -> [a] -> Exp [a]
- data Span :: (a -> Exp Bool) -> [a] -> Exp ([a], [a])
- data Break :: (a -> Exp Bool) -> [a] -> Exp ([a], [a])
- data Tails :: [a] -> Exp [[a]]
- data IsPrefixOf :: [a] -> [a] -> Exp Bool
- data IsSuffixOf :: [a] -> [a] -> Exp Bool
- data IsInfixOf :: [a] -> [a] -> Exp Bool
- data Elem :: a -> [a] -> Exp Bool
- data Lookup :: k -> [(k, b)] -> Exp (Maybe b)
- data Find :: (a -> Exp Bool) -> [a] -> Exp (Maybe a)
- data Filter :: (a -> Exp Bool) -> [a] -> Exp [a]
- data Partition :: (a -> Exp Bool) -> [a] -> Exp ([a], [a])
- data FindIndex :: (a -> Exp Bool) -> [a] -> Exp (Maybe Nat)
- data SetIndex :: Nat -> a -> [a] -> Exp [a]
- data ZipWith :: (a -> b -> Exp c) -> [a] -> [b] -> Exp [c]
- data Zip :: [a] -> [b] -> Exp [(a, b)]
- data Unzip :: Exp [(a, b)] -> Exp ([a], [b])
Basic functions
data (++) :: [a] -> [a] -> Exp [a] Source #
List catenation.
Example
>>>data Example where Ex :: a -> Example -- Hide the type of examples to avoid brittleness in different GHC versions>>>:kind! Ex (Eval ([1, 2] ++ [3, 4]) :: [Natural])Ex (Eval ([1, 2] ++ [3, 4]) :: [Natural]) :: Example = Ex [1, 2, 3, 4]
data Cons :: a -> [a] -> Exp [a] Source #
Append an element to a list.
Example
>>>:kind! Eval (Cons 1 [2, 3])Eval (Cons 1 [2, 3]) :: [Natural] = [1, 2, 3]>>>:kind! Eval (Cons Int [Char, Maybe Double])Eval (Cons Int [Char, Maybe Double]) :: [*] = [Int, Char, Maybe Double]
data Snoc :: [a] -> a -> Exp [a] Source #
Append an element to the end of a list.
Example
>>>:kind! Eval (Snoc [1,2,3] 4)Eval (Snoc [1,2,3] 4) :: [Natural] = [1, 2, 3, 4]
data Cons2 :: (a, b) -> ([a], [b]) -> Exp ([a], [b]) Source #
Append elements to two lists. Used in the definition of Unzip.
List transformations
data Reverse :: [a] -> Exp [a] Source #
Reverse a list.
Example
>>>:kind! Eval (Reverse [1,2,3,4,5])Eval (Reverse [1,2,3,4,5]) :: [Natural] = [5, 4, 3, 2, 1]
data Intersperse :: a -> [a] -> Exp [a] Source #
Intersperse a separator between elements of a list.
Example
>>>:kind! Eval (Intersperse 0 [1,2,3,4])Eval (Intersperse 0 [1,2,3,4]) :: [Natural] = [1, 0, 2, 0, 3, 0, 4]
Instances
| type Eval (Intersperse _1 ('[] :: [a]) :: [a] -> Type) Source # | |
Defined in Fcf.Data.List | |
| type Eval (Intersperse sep (x ': xs) :: [a] -> Type) Source # | |
Defined in Fcf.Data.List | |
data Intercalate :: [a] -> [[a]] -> Exp [a] Source #
Join a list of words separated by some word.
Example
>>>:kind! Eval (Intercalate '[", "] [ '["Lorem"], '["ipsum"], '["dolor"] ])Eval (Intercalate '[", "] [ '["Lorem"], '["ipsum"], '["dolor"] ]) :: [TL.Symbol] = ["Lorem", ", ", "ipsum", ", ", "dolor"]
Instances
| type Eval (Intercalate xs xss :: [a] -> Type) Source # | |
Defined in Fcf.Data.List type Eval (Intercalate xs xss :: [a] -> Type) = Eval ((Concat :: [[a]] -> [a] -> Type) =<< Intersperse xs xss) | |
Reducing lists
See also Fcf.Class.Foldable.
data Foldr :: (a -> b -> Exp b) -> b -> t a -> Exp b Source #
Right fold.
Example
>>>:kind! Eval (Foldr (+) 0 [1, 2, 3, 4])Eval (Foldr (+) 0 [1, 2, 3, 4]) :: Natural = 10
Instances
| type Eval (Foldr f y ('Left _a :: Either a3 a1) :: a2 -> Type) Source # | |
| type Eval (Foldr f y ('Right x :: Either a3 a1) :: a2 -> Type) Source # | |
| type Eval (Foldr f y ('Just x) :: a2 -> Type) Source # | |
| type Eval (Foldr f y ('Nothing :: Maybe a1) :: a2 -> Type) Source # | |
| type Eval (Foldr f y (x ': xs) :: a2 -> Type) Source # | |
| type Eval (Foldr f y ('[] :: [a1]) :: a2 -> Type) Source # | |
Defined in Fcf.Class.Foldable | |
data UnList :: b -> (a -> b -> Exp b) -> [a] -> Exp b Source #
This is Foldr with its argument flipped.
data Concat :: t m -> Exp m Source #
Concatenate a collection of elements from a monoid.
Example
For example, fold a list of lists.
Concat :: [[a]] -> Exp [a]
>>>:kind! Eval (Concat ([[1,2], [3,4], [5,6]]))Eval (Concat ([[1,2], [3,4], [5,6]])) :: [Natural] = [1, 2, 3, 4, 5, 6]>>>:kind! Eval (Concat ([[Int, Maybe Int], [Maybe String, Either Double Int]]))Eval (Concat ([[Int, Maybe Int], [Maybe String, Either Double Int]])) :: [*] = [Int, Maybe Int, Maybe [Char], Either Double Int]
data ConcatMap :: (a -> Exp [b]) -> t a -> Exp [b] Source #
Map a function and concatenate the results.
This is FoldMap specialized to the list monoid.
Unfolding and building
data Unfoldr :: (b -> Exp (Maybe (a, b))) -> b -> Exp [a] Source #
Unfold a generator into a list.
Example
>>>data ToThree :: Nat -> Exp (Maybe (Nat, Nat))>>>:{type instance Eval (ToThree b) = If (4 TL.<=? b) Nothing (Just '(b, b TL.+ 1)) :}
>>>:kind! Eval (Unfoldr ToThree 0)Eval (Unfoldr ToThree 0) :: [Natural] = [0, 1, 2, 3]
See also the definition of Replicate.
data Replicate :: Nat -> a -> Exp [a] Source #
Repeat the same element in a list.
Example
>>>:kind! Eval (Replicate 4 '("ok", 2))Eval (Replicate 4 '("ok", 2)) :: [(TL.Symbol, Natural)] = ['("ok", 2), '("ok", 2), '("ok", 2), '("ok", 2)]
Sublists
data Take :: Nat -> [a] -> Exp [a] Source #
Take a prefix of fixed length.
Example
>>>:kind! Eval (Take 2 [1,2,3,4,5])Eval (Take 2 [1,2,3,4,5]) :: [Natural] = [1, 2]
data Drop :: Nat -> [a] -> Exp [a] Source #
Drop a prefix of fixed length, evaluate to the remaining suffix.
Example
>>>:kind! Eval (Drop 2 [1,2,3,4,5])Eval (Drop 2 [1,2,3,4,5]) :: [Natural] = [3, 4, 5]
data TakeWhile :: (a -> Exp Bool) -> [a] -> Exp [a] Source #
Take the longest prefix of elements satisfying a predicate.
Example
>>>:kind! Eval (TakeWhile ((>=) 3) [1, 2, 3, 4, 5])Eval (TakeWhile ((>=) 3) [1, 2, 3, 4, 5]) :: [Natural] = [1, 2, 3]
data DropWhile :: (a -> Exp Bool) -> [a] -> Exp [a] Source #
Drop the longest prefix of elements satisfying a predicate, evaluate to the remaining suffix.
Example
:kind! Eval (DropWhile ((>=) 3) [1, 2, 3, 4, 5]) Eval (DropWhile ((>=) 3) [1, 2, 3, 4, 5]) :: [Natural] = [4, 5]
data Span :: (a -> Exp Bool) -> [a] -> Exp ([a], [a]) Source #
Span, applied to a predicate p and a list xs, returns a tuple:
the first component is the longest prefix (possibly empty) of xs whose elements
satisfy p;
the second component is the remainder of the list.
See also TakeWhile, DropWhile, and Break.
Example
>>>:kind! Eval (Span (Flip (<) 3) [1,2,3,4,1,2])Eval (Span (Flip (<) 3) [1,2,3,4,1,2]) :: ([Natural], [Natural]) = '([1, 2], [3, 4, 1, 2])
>>>:kind! Eval (Span (Flip (<) 9) [1,2,3])Eval (Span (Flip (<) 9) [1,2,3]) :: ([Natural], [Natural]) = '([1, 2, 3], '[])
>>>:kind! Eval (Span (Flip (<) 0) [1,2,3])Eval (Span (Flip (<) 0) [1,2,3]) :: ([Natural], [Natural]) = '( '[], [1, 2, 3])
data Break :: (a -> Exp Bool) -> [a] -> Exp ([a], [a]) Source #
Break, applied to a predicate p and a list xs, returns a tuple:
the first component is the longest prefix (possibly empty) of xs whose elements
do not satisfy p; the second component is the remainder of the list.
Example
>>>:kind! Eval (Break (Flip (>) 3) [1,2,3,4,1,2])Eval (Break (Flip (>) 3) [1,2,3,4,1,2]) :: ([Natural], [Natural]) = '([1, 2, 3], [4, 1, 2])
>>>:kind! Eval (Break (Flip (<) 9) [1,2,3])Eval (Break (Flip (<) 9) [1,2,3]) :: ([Natural], [Natural]) = '( '[], [1, 2, 3])
>>>:kind! Eval (Break (Flip (>) 9) [1,2,3])Eval (Break (Flip (>) 9) [1,2,3]) :: ([Natural], [Natural]) = '([1, 2, 3], '[])
data Tails :: [a] -> Exp [[a]] Source #
List of suffixes of a list.
Example
>>>:kind! Eval (Tails [0,1,2,3])Eval (Tails [0,1,2,3]) :: [[Natural]] = [[0, 1, 2, 3], [1, 2, 3], [2, 3], '[3]]
Predicates
data IsPrefixOf :: [a] -> [a] -> Exp Bool Source #
Return True when the first list is a prefix of the second.
Example
>>>:kind! Eval ([0,1,2] `IsPrefixOf` [0,1,2,3,4,5])Eval ([0,1,2] `IsPrefixOf` [0,1,2,3,4,5]) :: Bool = True
>>>:kind! Eval ([0,1,2] `IsPrefixOf` [0,1,3,2,4,5])Eval ([0,1,2] `IsPrefixOf` [0,1,3,2,4,5]) :: Bool = False
>>>:kind! Eval ('[] `IsPrefixOf` [0,1,3,2,4,5])Eval ('[] `IsPrefixOf` [0,1,3,2,4,5]) :: Bool = True
>>>:kind! Eval ([0,1,3,2,4,5] `IsPrefixOf` '[])Eval ([0,1,3,2,4,5] `IsPrefixOf` '[]) :: Bool = False
Instances
| type Eval (IsPrefixOf xs ys :: Bool -> Type) Source # | |
Defined in Fcf.Data.List | |
data IsSuffixOf :: [a] -> [a] -> Exp Bool Source #
Return True when the first list is a suffix of the second.
Example
>>>:kind! Eval (IsSuffixOf [3,4,5] [0,1,2,3,4,5])Eval (IsSuffixOf [3,4,5] [0,1,2,3,4,5]) :: Bool = True
>>>:kind! Eval (IsSuffixOf [3,4,5] [0,1,3,2,4,5])Eval (IsSuffixOf [3,4,5] [0,1,3,2,4,5]) :: Bool = False
>>>:kind! Eval (IsSuffixOf '[] [0,1,3,2,4,5])Eval (IsSuffixOf '[] [0,1,3,2,4,5]) :: Bool = True
>>>:kind! Eval (IsSuffixOf [0,1,3,2,4,5] '[])Eval (IsSuffixOf [0,1,3,2,4,5] '[]) :: Bool = False
Instances
| type Eval (IsSuffixOf xs ys :: Bool -> Type) Source # | |
Defined in Fcf.Data.List | |
data IsInfixOf :: [a] -> [a] -> Exp Bool Source #
Return True when the first list is contained within the second.
Example
>>>:kind! Eval (IsInfixOf [2,3,4] [0,1,2,3,4,5,6])Eval (IsInfixOf [2,3,4] [0,1,2,3,4,5,6]) :: Bool = True
>>>:kind! Eval (IsInfixOf [2,4,4] [0,1,2,3,4,5,6])Eval (IsInfixOf [2,4,4] [0,1,2,3,4,5,6]) :: Bool = False
Searching
data Elem :: a -> [a] -> Exp Bool Source #
Return True if an element is in a list.
See also FindIndex.
Example
>>>:kind! Eval (Elem 1 [1,2,3])Eval (Elem 1 [1,2,3]) :: Bool = True>>>:kind! Eval (Elem 1 [2,3])Eval (Elem 1 [2,3]) :: Bool = False
data Lookup :: k -> [(k, b)] -> Exp (Maybe b) Source #
Find an element associated with a key in an association list.
data Find :: (a -> Exp Bool) -> [a] -> Exp (Maybe a) Source #
Find Just the first element satisfying a predicate, or evaluate to
Nothing if no element satisfies the predicate.
Example
>>>:kind! Eval (Find (TyEq 0) [1,2,3])Eval (Find (TyEq 0) [1,2,3]) :: Maybe Natural = Nothing
>>>:kind! Eval (Find (TyEq 0) [1,2,3,0])Eval (Find (TyEq 0) [1,2,3,0]) :: Maybe Natural = Just 0
data Filter :: (a -> Exp Bool) -> [a] -> Exp [a] Source #
Keep all elements that satisfy a predicate, remove all that don't.
Example
>>>:kind! Eval (Filter ((>) 3) [1,2,3,0])Eval (Filter ((>) 3) [1,2,3,0]) :: [Natural] = [1, 2, 0]
data Partition :: (a -> Exp Bool) -> [a] -> Exp ([a], [a]) Source #
Split a list into one where all elements satisfy a predicate, and a second where no elements satisfy it.
Example
>>>:kind! Eval (Partition ((>=) 35) [20, 30, 40, 50])Eval (Partition ((>=) 35) [20, 30, 40, 50]) :: ([Natural], [Natural]) = '([20, 30], [40, 50])
Indexing lists
data FindIndex :: (a -> Exp Bool) -> [a] -> Exp (Maybe Nat) Source #
Find the index of an element satisfying the predicate.
Example
>>>:kind! Eval (FindIndex ((<=) 3) [1,2,3,1,2,3])Eval (FindIndex ((<=) 3) [1,2,3,1,2,3]) :: Maybe Natural = Just 2
>>>:kind! Eval (FindIndex ((>) 0) [1,2,3,1,2,3])Eval (FindIndex ((>) 0) [1,2,3,1,2,3]) :: Maybe Natural = Nothing
data SetIndex :: Nat -> a -> [a] -> Exp [a] Source #
Modify an element at a given index.
The list is unchanged if the index is out of bounds.
Example
>>>:kind! Eval (SetIndex 2 7 [1,2,3])Eval (SetIndex 2 7 [1,2,3]) :: [Natural] = [1, 2, 7]
Zipping and unzipping
data ZipWith :: (a -> b -> Exp c) -> [a] -> [b] -> Exp [c] Source #
Combine elements of two lists pairwise.
Example
>>>:kind! Eval (ZipWith (+) [1,2,3] [1,1,1])Eval (ZipWith (+) [1,2,3] [1,1,1]) :: [Natural] = [2, 3, 4]