Modulefirst-class-families-0.8.2.0Haskell2010

Fcf.Data.List

Lists.

See also Fcf.Class.Foldable for additional functions.

Contents

Basic functions
List transformations
Reducing lists
Unfolding and building
Sublists
Predicates
Searching
Indexing lists
Zipping and unzipping

Synopsis

data ++
data Head
data Last
data Tail
data Cons
data Snoc
data Cons2
data Init
data Uncons
data Unsnoc
data Singleton
data Null
data Length
data Reverse
data Intersperse
data Intercalate
data Foldr
data UnList
data Concat
data ConcatMap
data Unfoldr
data Replicate
data Take
data Drop
data SplitAt
data TakeWhile
data DropWhile
data Span
data Break
data Tails
data IsPrefixOf
data IsSuffixOf
data IsInfixOf
data Elem
data Lookup
data Find
data Filter
data Partition
data FindIndex
data SetIndex
data ZipWith
data Zip
data Unzip

Packagefirst-class-families-0.8.2.0
Exports43
LanguageHaskell2010
LicenceMIT
SourceList.hs

Basic functions

datadata (++) (b :: [a]) (c :: [a]) (d :: [a])

Source#

List catenation.

Example

Example2 expressions

>>> 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]

Instances1Eval

type Eval (xs ++ ys) = xs <> ysDefined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Head (b :: [a]) (c :: Maybe a)

Instances2Eval

type Eval (Head '[]) = 'NothingDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Head (a2 ': _as)) = 'Just a2Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Last (b :: [a]) (c :: Maybe a)

Instances3Eval

type Eval (Last '[a2]) = 'Just a2Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Last '[]) = 'NothingDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Last (a2 ': b ': as)) = Eval (Last (b ': as))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Tail (b :: [a]) (c :: Maybe [a])

Instances2Eval

type Eval (Tail '[]) = 'NothingDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Tail (_a ': as)) = 'Just asDefined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Cons (b :: a) (c :: [a]) (d :: [a])

Source#

Append an element to a list.

Example

Example2 expressions

>>> :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]

Instances1Eval

type Eval (Cons a2 as) = a2 ': asDefined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Snoc (b :: [a]) (c :: a) (d :: [a])

Source#

Append an element to the end of a list.

Example

Example1 expression

>>> :kind! Eval (Snoc [1,2,3] 4)Eval (Snoc [1,2,3] 4) :: [Natural]= [1, 2, 3, 4]

Instances1Eval

type Eval (Snoc lst a) = Eval (lst ++ '[a])Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Cons2 (c :: (a, b)) (d :: ([a], [b])) (e :: ([a], [b]))

Source#

Append elements to two lists. Used in the definition of Unzip.

Instances1Eval

type Eval (Cons2 '(a3, b) '(as, bs)) = '(a3 ': as, b ': bs)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Init (b :: [a]) (c :: Maybe [a])

Instances3Eval

type Eval (Init '[a2]) = 'Just '[]Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Init '[]) = 'NothingDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Init (a2 ': b ': as)) = Eval (Map (Cons a2) =<< Init (b ': as))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Uncons (b :: [a]) (c :: Maybe (a, [a]))

Instances2Eval

type Eval (Uncons '[]) = 'NothingDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Uncons (a ': xs)) = 'Just '(a, xs)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Unsnoc (b :: [a]) (c :: Maybe ([a], a))

Source#

Decompose a list into init and last

Example

Example1 expression

>>> :kind! Eval (Unsnoc '[])Eval (Unsnoc '[]) :: Maybe ([a], a)= Nothing

Example1 expression

>>> :kind! Eval (Unsnoc '[1])Eval (Unsnoc '[1]) :: Maybe ([Natural], Natural)= Just '( '[], 1)

Example1 expression

>>> :kind! Eval (Unsnoc '[1,2,3])Eval (Unsnoc '[1,2,3]) :: Maybe ([Natural], Natural)= Just '([1, 2], 3)

Instances3Eval

type Eval (Unsnoc '[x]) = 'Just '('[], x)Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Unsnoc '[]) = 'NothingDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Unsnoc (x ': y ': ys)) = Eval (Map (PrependF x) =<< Unsnoc (y ': ys))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Singleton (b :: a) (c :: [a])

Instances1Eval

type Eval (Singleton x) = '[x]Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Null (b :: [a]) (c :: Bool)

Instances2Eval

type Eval (Null '[]) = 'TrueDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Null (a2 ': as)) = 'FalseDefined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Length (b :: [a]) (c :: Nat)

Instances2Eval

type Eval (Length '[]) = 0Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Length (a2 ': as)) = 1 + Eval (Length as)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

List transformations

datadata Reverse (b :: [a]) (c :: [a])

Source#

Reverse a list.

Example

Example1 expression

>>> :kind! Eval (Reverse [1,2,3,4,5])Eval (Reverse [1,2,3,4,5]) :: [Natural]= [5, 4, 3, 2, 1]

Instances1Eval

type Eval (Reverse l) = Eval (Rev l '[])Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Intersperse (b :: a) (c :: [a]) (d :: [a])

Source#

Intersperse a separator between elements of a list.

Example

Example1 expression

>>> :kind! Eval (Intersperse 0 [1,2,3,4])Eval (Intersperse 0 [1,2,3,4]) :: [Natural]= [1, 0, 2, 0, 3, 0, 4]

Instances2Eval

type Eval (Intersperse _1 '[]) = '[]Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Intersperse sep (x ': xs)) = x ': Eval (PrependToAll sep xs)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Intercalate (b :: [a]) (c :: [[a]]) (d :: [a])

Source#

Join a list of words separated by some word.

Example

Example1 expression

>>> :kind! Eval (Intercalate '[", "] [ '["Lorem"], '["ipsum"], '["dolor"] ])Eval (Intercalate '[", "] [ '["Lorem"], '["ipsum"], '["dolor"] ]) :: [TL.Symbol]= ["Lorem", ", ", "ipsum", ", ", "dolor"]

Instances1Eval

type Eval (Intercalate xs xss) = Eval (Concat =<< Intersperse xs xss)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

Reducing lists

Example

Example1 expression

>>> :kind! Eval (Foldr (+) 0 [1, 2, 3, 4])Eval (Foldr (+) 0 [1, 2, 3, 4]) :: Natural= 10

Instances6Eval

type Eval (Foldr f y 'Nothing) = yDefined in first-class-families-0.8.2.0 · Fcf.Class.Foldable
type Eval (Foldr f y '[]) = yDefined in first-class-families-0.8.2.0 · Fcf.Class.Foldable
type Eval (Foldr f y ('Left _a)) = yDefined in first-class-families-0.8.2.0 · Fcf.Class.Foldable
type Eval (Foldr f y ('Right x)) = Eval (f x y)Defined in first-class-families-0.8.2.0 · Fcf.Class.Foldable
type Eval (Foldr f y ('Just x)) = Eval (f x y)Defined in first-class-families-0.8.2.0 · Fcf.Class.Foldable
type Eval (Foldr f y (x ': xs)) = Eval (f x (Eval (Foldr f y xs)))Defined in first-class-families-0.8.2.0 · Fcf.Class.Foldable

datadata UnList (c :: b) (d :: a -> b -> Exp b) (e :: [a]) (f :: b)

Source#

This is Foldr with its argument flipped.

Instances1Eval

type Eval (UnList y f xs) = Eval (Foldr f y xs)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Concat (a :: t m) (b :: m)

Source#

Concatenate a collection of elements from a monoid.

Example

For example, fold a list of lists.

Concat :: [[a]] -> Exp [a]

Example2 expressions

>>> :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]

Instances1Eval

type Eval (Concat xs) = Eval (FoldMap Pure xs)Defined in first-class-families-0.8.2.0 · Fcf.Class.Foldable

datadata ConcatMap (c :: a -> Exp [b]) (d :: t a) (e :: [b])

Source#

Map a function and concatenate the results.

This is FoldMap specialized to the list monoid.

Instances1Eval

type Eval (ConcatMap f xs) = Eval (FoldMap f xs)Defined in first-class-families-0.8.2.0 · Fcf.Class.Foldable

Unfolding and building

datadata Unfoldr (c :: b -> Exp (Maybe (a, b))) (d :: b) (e :: [a])

Source#

Unfold a generator into a list.

Example

Example2 expressions

>>> data ToThree :: Nat -> Exp (Maybe (Nat, Nat))>>> :{type instance Eval (ToThree b) =  If (4 TL.<=? b)    Nothing    (Just '(b, b TL.+ 1)):}

Example1 expression

>>> :kind! Eval (Unfoldr ToThree 0)Eval (Unfoldr ToThree 0) :: [Natural]= [0, 1, 2, 3]

Example

Example1 expression

>>> :kind! Eval (Replicate 4 '("ok", 2))Eval (Replicate 4 '("ok", 2)) :: [(TL.Symbol, Natural)]= ['("ok", 2), '("ok", 2), '("ok", 2), '("ok", 2)]

Instances1Eval

type Eval (Replicate n a2) = Eval (Unfoldr (NumIter a2) n)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

Sublists

datadata Take (b :: Nat) (c :: [a]) (d :: [a])

Source#

Take a prefix of fixed length.

Example

Example1 expression

>>> :kind! Eval (Take 2 [1,2,3,4,5])Eval (Take 2 [1,2,3,4,5]) :: [Natural]= [1, 2]

Instances1Eval

type Eval (Take n as) = Take_ n asDefined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Drop (b :: Nat) (c :: [a]) (d :: [a])

Source#

Drop a prefix of fixed length, evaluate to the remaining suffix.

Example

Example1 expression

>>> :kind! Eval (Drop 2 [1,2,3,4,5])Eval (Drop 2 [1,2,3,4,5]) :: [Natural]= [3, 4, 5]

Instances1Eval

type Eval (Drop n as) = Drop_ n asDefined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata SplitAt (b :: Nat) (c :: [a]) (d :: ([a], [a]))

Source#

Return a tuple where first element is xs prefix of length n and second element is the remainder of the list.

Example

Example1 expression

>>> :kind! Eval (SplitAt 3 '[1,2,3,4,5])Eval (SplitAt 3 '[1,2,3,4,5]) :: ([Natural], [Natural])= '([1, 2, 3], [4, 5])

Instances1Eval

type Eval (SplitAt n xs) = '(Eval (Take n xs), Eval (Drop n xs))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata TakeWhile (b :: a -> Exp Bool) (c :: [a]) (d :: [a])

Source#

Take the longest prefix of elements satisfying a predicate.

Example

Example1 expression

>>> :kind! Eval (TakeWhile ((>=) 3) [1, 2, 3, 4, 5])Eval (TakeWhile ((>=) 3) [1, 2, 3, 4, 5]) :: [Natural]= [1, 2, 3]

Instances2Eval

type Eval (TakeWhile p '[]) = '[]Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (TakeWhile p (x ': xs)) = Eval (If (Eval (p x)) ('(:) x <$> TakeWhile p xs) (Pure '[]))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata DropWhile (b :: a -> Exp Bool) (c :: [a]) (d :: [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]

Instances2Eval

type Eval (DropWhile p '[]) = '[]Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (DropWhile p (x ': xs)) = Eval (If (Eval (p x)) (DropWhile p xs) (Pure (x ': xs)))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Span (b :: a -> Exp Bool) (c :: [a]) (d :: ([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

Example1 expression

>>> :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])

Example1 expression

>>> :kind! Eval (Span (Flip (<) 9) [1,2,3])Eval (Span (Flip (<) 9) [1,2,3]) :: ([Natural], [Natural])= '([1, 2, 3], '[])

Example1 expression

>>> :kind! Eval (Span (Flip (<) 0) [1,2,3])Eval (Span (Flip (<) 0) [1,2,3]) :: ([Natural], [Natural])= '( '[], [1, 2, 3])

Instances1Eval

type Eval (Span p lst) = '(Eval (TakeWhile p lst), Eval (DropWhile p lst))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Break (b :: a -> Exp Bool) (c :: [a]) (d :: ([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

Example1 expression

>>> :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])

Example1 expression

>>> :kind! Eval (Break (Flip (<) 9) [1,2,3])Eval (Break (Flip (<) 9) [1,2,3]) :: ([Natural], [Natural])= '( '[], [1, 2, 3])

Example1 expression

>>> :kind! Eval (Break (Flip (>) 9) [1,2,3])Eval (Break (Flip (>) 9) [1,2,3]) :: ([Natural], [Natural])= '([1, 2, 3], '[])

Instances1Eval

type Eval (Break p lst) = Eval (Span (Not <=< p) lst)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Tails (b :: [a]) (c :: [[a]])

Source#

List of suffixes of a list.

Example

Example1 expression

>>> :kind! Eval (Tails [0,1,2,3])Eval (Tails [0,1,2,3]) :: [[Natural]]= [[0, 1, 2, 3], [1, 2, 3], [2, 3], '[3]]

Instances2Eval

type Eval (Tails '[]) = '[]Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Tails (a2 ': as)) = (a2 ': as) ': Eval (Tails as)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

Predicates

datadata IsPrefixOf (b :: [a]) (c :: [a]) (d :: Bool)

Source#

Return True when the first list is a prefix of the second.

Example

Example1 expression

>>> :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

Example1 expression

>>> :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

Example1 expression

>>> :kind! Eval ('[] `IsPrefixOf` [0,1,3,2,4,5])Eval ('[] `IsPrefixOf` [0,1,3,2,4,5]) :: Bool= True

Example1 expression

>>> :kind! Eval ([0,1,3,2,4,5] `IsPrefixOf` '[])Eval ([0,1,3,2,4,5] `IsPrefixOf` '[]) :: Bool= False

Instances1Eval

type Eval (IsPrefixOf xs ys) = IsPrefixOf_ xs ysDefined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata IsSuffixOf (b :: [a]) (c :: [a]) (d :: Bool)

Source#

Return True when the first list is a suffix of the second.

Example

Example1 expression

>>> :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

Example1 expression

>>> :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

Example1 expression

>>> :kind! Eval (IsSuffixOf '[] [0,1,3,2,4,5])Eval (IsSuffixOf '[] [0,1,3,2,4,5]) :: Bool= True

Example1 expression

>>> :kind! Eval (IsSuffixOf [0,1,3,2,4,5] '[])Eval (IsSuffixOf [0,1,3,2,4,5] '[]) :: Bool= False

Instances1Eval

type Eval (IsSuffixOf xs ys) = Eval (IsPrefixOf (Reverse @@ xs) (Reverse @@ ys))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata IsInfixOf (b :: [a]) (c :: [a]) (d :: Bool)

Source#

Return True when the first list is contained within the second.

Example

Example1 expression

>>> :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

Example1 expression

>>> :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

Instances1Eval

type Eval (IsInfixOf xs ys) = Eval (Any (IsPrefixOf xs) =<< Tails ys)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

Searching

datadata Elem (b :: a) (c :: [a]) (d :: Bool)

Source#

Return True if an element is in a list.

Example

Example2 expressions

>>> :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

Instances1Eval

type Eval (Elem a2 as) = Eval (IsJust =<< FindIndex (TyEq a2) as)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Lookup (a :: k) (c :: [(k, b)]) (d :: Maybe b)

Source#

Find an element associated with a key in an association list.

Instances1Eval

type Eval (Lookup a as) = Eval (Map Snd (Eval (Find (TyEq a <=< Fst) as)))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Find (b :: a -> Exp Bool) (c :: [a]) (d :: Maybe a)

Source#

Find Just the first element satisfying a predicate, or evaluate to Nothing if no element satisfies the predicate.

Example

Example1 expression

>>> :kind! Eval (Find (TyEq 0) [1,2,3])Eval (Find (TyEq 0) [1,2,3]) :: Maybe Natural= Nothing

Example1 expression

>>> :kind! Eval (Find (TyEq 0) [1,2,3,0])Eval (Find (TyEq 0) [1,2,3,0]) :: Maybe Natural= Just 0

Instances2Eval

type Eval (Find _p '[]) = 'NothingDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Find p (a2 ': as)) = Eval (If (Eval (p a2)) (Pure ('Just a2)) (Find p as))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Filter (b :: a -> Exp Bool) (c :: [a]) (d :: [a])

Source#

Keep all elements that satisfy a predicate, remove all that don't.

Example

Example1 expression

>>> :kind! Eval (Filter ((>) 3) [1,2,3,0])Eval (Filter ((>) 3) [1,2,3,0]) :: [Natural]= [1, 2, 0]

Instances2Eval

type Eval (Filter _p '[]) = '[]Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (Filter p (a2 ': as)) = Eval (If (Eval (p a2)) ('(:) a2 <$> Filter p as) (Filter p as))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Partition (b :: a -> Exp Bool) (c :: [a]) (d :: ([a], [a]))

Source#

Split a list into one where all elements satisfy a predicate, and a second where no elements satisfy it.

Example

Example1 expression

>>> :kind! Eval (Partition ((>=) 35) [20, 30, 40, 50])Eval (Partition ((>=) 35) [20, 30, 40, 50]) :: ([Natural],                                                [Natural])= '([20, 30], [40, 50])

Instances1Eval

type Eval (Partition p lst) = Eval (Foldr (PartHelp p) '('[], '[]) lst)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

Indexing lists

datadata FindIndex (b :: a -> Exp Bool) (c :: [a]) (d :: Maybe Nat)

Source#

Find the index of an element satisfying the predicate.

Example

Example1 expression

>>> :kind! Eval (FindIndex ((<=) 3) [1,2,3,1,2,3])Eval (FindIndex ((<=) 3) [1,2,3,1,2,3]) :: Maybe Natural= Just 2

Example1 expression

>>> :kind! Eval (FindIndex ((>) 0) [1,2,3,1,2,3])Eval (FindIndex ((>) 0) [1,2,3,1,2,3]) :: Maybe Natural= Nothing

Instances2Eval

type Eval (FindIndex _p '[]) = 'NothingDefined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (FindIndex p (a2 ': as)) = Eval (If (Eval (p a2)) (Pure ('Just 0)) (Map ((+) 1) =<< FindIndex p as))Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata SetIndex (b :: Nat) (c :: a) (d :: [a]) (e :: [a])

Source#

Modify an element at a given index.

The list is unchanged if the index is out of bounds.

Example

Example1 expression

>>> :kind! Eval (SetIndex 2 7 [1,2,3])Eval (SetIndex 2 7 [1,2,3]) :: [Natural]= [1, 2, 7]

Instances1Eval

type Eval (SetIndex n a' as) = SetIndexImpl n a' asDefined in first-class-families-0.8.2.0 · Fcf.Data.List

Zipping and unzipping

datadata ZipWith (d :: a -> b -> Exp c) (e :: [a]) (f :: [b]) (g :: [c])

Source#

Combine elements of two lists pairwise.

Example

Example1 expression

>>> :kind! Eval (ZipWith (+) [1,2,3] [1,1,1])Eval (ZipWith (+) [1,2,3] [1,1,1]) :: [Natural]= [2, 3, 4]

Instances3Eval

type Eval (ZipWith _f '[] _bs) = '[]Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (ZipWith _f _as '[]) = '[]Defined in first-class-families-0.8.2.0 · Fcf.Data.List
type Eval (ZipWith f (a2 ': as) (b2 ': bs)) = Eval (f a2 b2) ': Eval (ZipWith f as bs)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Zip (c :: [a]) (d :: [b]) (e :: [(a, b)])

Instances1Eval

type Eval (Zip as bs) = Eval (ZipWith (Pure2 '((,))) as bs)Defined in first-class-families-0.8.2.0 · Fcf.Data.List

datadata Unzip (c :: Exp [(a, b)]) (d :: ([a], [b]))

Instances1Eval

type Eval (Unzip as) = Eval (Foldr Cons2 '('[], '[]) (Eval as))Defined in first-class-families-0.8.2.0 · Fcf.Data.List