137 lines
3.8 KiB
Elm
137 lines
3.8 KiB
Elm
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module List where
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import Native.Utils (min, max)
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import Native.List as L
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-- Add an element to the front of a list
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-- a :: [b,c] = [a,b,c]
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(::) : a -> [a] -> [a]
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-- Appends two lists.
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(++) : Appendable a -> Appendable a -> Appendable a
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-- Extract the first element of a list. List must be non-empty.
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head : [a] -> a
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-- Extract the elements after the head of the list. List must be non-empty.
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tail : [a] -> [a]
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-- Extract the last element of a list. List must be non-empty.
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last : [a] -> a
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-- Apply a function to every element of a list.
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map : (a -> b) -> [a] -> [b]
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-- Reduce a list from the left.
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foldl : (a -> b -> b) -> b -> [a] -> b
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-- Reduce a list from the right.
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foldr : (a -> b -> b) -> b -> [a] -> b
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-- Reduce a list from the left without a base case. List must be non-empty.
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foldl1 : (a -> a -> a) -> [a] -> a
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-- Reduce a list from the right without a base case. List must be non-empty.
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foldr1 : (a -> a -> a) -> [a] -> a
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-- Reduce a list from the left, building up all of the intermediate results into a list.
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scanl : (a -> b -> b) -> b -> [a] -> [b]
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-- Same as scanl but it doesn't require a base case. List must be non-empty.
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scanl1 : (a -> a -> a) -> [a] -> [a]
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-- Filter out elements which do not satisfy the predicate.
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filter : (a -> Bool) -> [a] -> [a]
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-- Determine the length of a list.
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length : [a] -> Int
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-- Reverse a list.
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reverse : [a] -> [a]
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-- Check to see if all elements satisfy the predicate.
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all : (a -> Bool) -> [a] -> Bool
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-- Check to see if any elements satisfy the predicate.
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any : (a -> Bool) -> [a] -> Bool
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-- Check to see if all elements are True.
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and : [Bool] -> Bool
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-- Check to see if any elements are True.
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or : [Bool] -> Bool
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-- Flatten a list of lists.
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concat : [Appendable a] -> Appendable a
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-- Map a given function onto a list and flatten the resulting lists.
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--
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-- concatMap f xs == concat (map f xs)
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concatMap : (a -> Appendable b) -> [a] -> Appendable b
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concatMap f = L.concat . L.map f
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-- Get the sum of the list elements.
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sum : [Number a] -> Number a
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sum = L.foldl (+) 0
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-- Get the product of the list elements.
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product : [Number a] -> Number a
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product = L.foldl (*) 1
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-- Find the highest number in a non-empty list.
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maximum : [Comparable a] -> Comparable a
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maximum = L.foldl1 max
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-- Find the lowest number in a non-empty list.
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minimum : [Comparable a] -> Comparable a
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minimum = L.foldl1 min
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-- Split a list based on the predicate.
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partition : (a -> Bool) -> [a] -> ([a],[a])
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partition pred lst =
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case lst of
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[] -> ([],[])
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x::xs -> let (bs,cs) = partition pred xs in
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if pred x then (x::bs,cs) else (bs,x::cs)
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-- Combine two lists, combining them into tuples pairwise. If one input list has extra elements (it is longer), those elements are dropped.
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zip : [a] -> [b] -> [(a,b)]
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-- Combine two lists, combining them with the given function. If one input list has extra elements (it is longer), those elements are dropped.
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zipWith : (a -> b -> c) -> [a] -> [b] -> [c]
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-- Decompose a list of tuples
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unzip : [(a,b)] -> ([a],[b])
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unzip pairs =
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case pairs of
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[] -> ([],[])
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(x,y)::ps -> let (xs,ys) = (unzip ps) in (x::xs,y::ys)
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-- Split a list
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--
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-- split "," "hello,there,friend" == ["hello", "there", "friend"]
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split : [a] -> [a] -> [[a]]
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-- Places the given value between all of the lists in the second argument
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-- and concatenates the result.
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--
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-- join xs xss = concat (intersperse xs xss)
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join : Appendable a -> [Appendable a] -> Appendable a
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-- Places the given value between all members of the given list.
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intersperse : a -> [a] -> [a]
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intersperse sep xs =
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case xs of
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a::b::cs -> a :: sep :: intersperse sep (b::cs)
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[a] -> [a]
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[] -> []
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-- Take the first n members of a list.
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-- take 2 [1,2,3,4]) ==> [1,2]
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take : Int -> [a] -> [a]
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-- Drop the first n members of a list.
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-- drop 2 [1,2,3,4]) ==> [3,4]
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drop : Int -> [a] -> [a]
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