scanr -package:foldl

scanr :: (a -> b -> b) -> b -> [a] -> [b]

base Prelude Data.List GHC.List, protolude Protolude, relude Relude.List.Reexport, numhask NumHask.Prelude

scanr is the right-to-left dual of scanl. Note that the order of parameters on the accumulating function are reversed compared to scanl. Also note that

head (scanr f z xs) == foldr f z xs.

Examples

>>> scanr (+) 0 [1..4]
[10,9,7,4,0]

>>> scanr (+) 42 []
[42]

>>> scanr (-) 100 [1..4]
[98,-97,99,-96,100]

>>> scanr (\nextChar reversedString -> nextChar : reversedString) "foo" ['a', 'b', 'c', 'd']
["abcdfoo","bcdfoo","cdfoo","dfoo","foo"]

>>> force $ scanr (+) 0 [1..]
*** Exception: stack overflow

scanr :: Foldable f => (a -> b -> b) -> b -> f a -> NonEmpty b

base Data.List.NonEmpty, base-compat Data.List.NonEmpty.Compat, rio RIO.NonEmpty, base-compat-batteries Data.List.NonEmpty.Compat

scanr is the right-to-left dual of scanl. Note that

head (scanr f z xs) == foldr f z xs.

scanr :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString

bytestring Data.ByteString Data.ByteString.Lazy

scanr is similar to foldr, but returns a list of successive reduced values from the right.

scanr f z [..., x{n-1}, xn] == [..., x{n-1} `f` (xn `f` z), xn `f` z, z]

Note that

head (scanr f z xs) == foldr f z xs
last (scanr f z xs) == z

scanr :: (Char -> Char -> Char) -> Char -> ByteString -> ByteString

bytestring Data.ByteString.Char8

scanr is the right-to-left dual of scanl.

scanr :: (Char -> Char -> Char) -> Char -> ByteString -> ByteString

bytestring Data.ByteString.Lazy.Char8

scanr is similar to foldr, but returns a list of successive reduced values from the right.

scanr f z [..., x{n-1}, xn] == [..., x{n-1} `f` (xn `f` z), xn `f` z, z]

Note that

head (scanr f z xs) == foldr f z xs
last (scanr f z xs) == z

scanr :: (Char -> Char -> Char) -> Char -> Text -> Text

text Data.Text Data.Text.Lazy, rio RIO.Text RIO.Text.Lazy

O(n) scanr is the right-to-left dual of scanl. Performs replacement on invalid scalar values.

scanr f v == reverse . scanl (flip f) v . reverse

scanr :: (a -> b -> b) -> b -> Seq a -> Seq b

containers Data.Sequence Data.Sequence.Internal, rio RIO.Seq

scanr is the right-to-left dual of scanl.

scanr :: (a -> b -> b) -> b -> [a] -> [b]

hedgehog Hedgehog.Internal.Prelude, base-compat Prelude.Compat, base-prelude BasePrelude, Cabal-syntax Distribution.Compat.Prelude, universum Universum.List.Reexport

scanr is the right-to-left dual of scanl. Note that the order of parameters on the accumulating function are reversed compared to scanl. Also note that

head (scanr f z xs) == foldr f z xs.

>>> scanr (+) 0 [1..4]
[10,9,7,4,0]

>>> scanr (+) 42 []
[42]

>>> scanr (-) 100 [1..4]
[98,-97,99,-96,100]

>>> scanr (\nextChar reversedString -> nextChar : reversedString) "foo" ['a', 'b', 'c', 'd']
["abcdfoo","bcdfoo","cdfoo","dfoo","foo"]

>>> force $ scanr (+) 0 [1..]
*** Exception: stack overflow

scanr :: (a -> b -> b) -> b -> [a] -> [b]

ghc GHC.Prelude.Basic

scanr :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString

rio RIO.ByteString

scanr is the right-to-left dual of scanl.

scanr :: (a -> b -> b) -> b -> [a] -> [b]

rio RIO.List, numeric-prelude NumericPrelude NumericPrelude.Base

scanr is the right-to-left dual of scanl. Note that

head (scanr f z xs) == foldr f z xs.

scanr :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v b

rio RIO.Vector

O(n) Right-to-left Haskell-style scan

scanr :: (a -> b -> b) -> b -> Vector a -> Vector b

rio RIO.Vector.Boxed

O(n) Right-to-left Haskell-style scan

scanr :: (Storable a, Storable b) => (a -> b -> b) -> b -> Vector a -> Vector b

rio RIO.Vector.Storable

O(n) Right-to-left Haskell-style scan

scanr :: (Unbox a, Unbox b) => (a -> b -> b) -> b -> Vector a -> Vector b

rio RIO.Vector.Unboxed

O(n) Right-to-left Haskell-style scan

scanr :: Traversable f => (a -> b -> b) -> b -> f a -> T f b

non-empty Data.NonEmpty

scanr :: (Char -> Char -> Char) -> Char -> JSString -> JSString

jsaddle Data.JSString

O(n) scanr is the right-to-left dual of scanl. Performs replacement on invalid scalar values.

scanr f v == reverse . scanl (flip f) v . reverse

scanr :: TextualMonoid t => (Char -> Char -> Char) -> Char -> t -> t

monoid-subclasses Data.Monoid.Textual

Equivalent to scanr from Data.List when applied to a String, but preserves all non-character data.

scanr :: (Storable a, Storable b) => (a -> b -> b) -> b -> Vector a -> Vector b

storablevector Data.StorableVector

scanr is the right-to-left dual of scanl.

scanr :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> Vector v n a -> Vector v (n + 1) b

vector-sized Data.Vector.Generic.Sized