# map

map f xs is the list obtained by applying f to each element of xs, i.e., > map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn] > map f [x1, x2, ...] == [f x1, f x2, ...]
O(n) map f xs is the ByteString obtained by applying f to each element of xs
O(n) map f t is the Text obtained by applying f to each element of t. Subject to fusion. Performs replacement on invalid scalar values.
O(n*min(n,W)). map f s is the set obtained by applying f to each element of s. It's worth noting that the size of the result may be smaller if, for some (x,y), x /= y && f x == f y
O(n) map f xs is the ByteString obtained by applying f to each element of xs.
O(n) map f xs is the ByteString obtained by applying f to each element of xs. This function is subject to array fusion.
O(n). Map a function over all values in the map. > map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
O(n). Map a function over all values in the map. > map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
O(n*log n). map f s is the set obtained by applying f to each element of s. It's worth noting that the size of the result may be smaller if, for some (x,y), x /= y && f x == f y
mapM f is equivalent to sequence . map f.
mapM_ f is equivalent to sequence_ . map f.
The mapAccumL function behaves like a combination of map and foldl; it applies a function to each element of a list, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new list.
The mapAccumL function behaves like a combination of fmap and foldl; it applies a function to each element of a structure, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new structure.
The mapAccumR function behaves like a combination of map and foldr; it applies a function to each element of a list, passing an accumulating parameter from right to left, and returning a final value of this accumulator together with the new list.
The mapAccumR function behaves like a combination of fmap and foldr; it applies a function to each element of a structure, passing an accumulating parameter from right to left, and returning a final value of this accumulator together with the new structure.
The mapAndUnzipM function maps its first argument over a list, returning the result as a pair of lists. This function is mainly used with complicated data structures or a state-transforming monad.
This function maps one exception into another as proposed in the paper "A semantics for imprecise exceptions".
This function maps one exception into another as proposed in the paper "A semantics for imprecise exceptions".
Map each element of a structure to a monadic action, evaluate these actions from left to right, and ignore the results.
The mapMaybe function is a version of map which can throw out elements. In particular, the functional argument returns something of type Maybe b. If this is Nothing, no element is added on to the result list. If it just Just b, then b is included in the result list.
O(n). The function mapAccum threads an accumulating argument through the map in ascending order of keys. > let f a b = (a ++ b, b ++ "X") > mapAccum f "Everything: " (fromList [(5,"a"), (3,"b")]) == ("Everything: ba", fromList [(3, "bX"), (5, "aX")])
O(n). The function mapAccum threads an accumulating argument through the map in ascending order of keys. > let f a b = (a ++ b, b ++ "X") > mapAccum f "Everything: " (fromList [(5,"a"), (3,"b")]) == ("Everything: ba", fromList [(3, "bX"), (5, "aX")])
O(n) Like a combination of map and foldl'. Applies a function to each element of a Text, passing an accumulating parameter from left to right, and returns a final Text. Performs replacement on invalid scalar values.
The mapAccumL function behaves like a combination of map and foldl; it applies a function to each element of a ByteString, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new ByteString.
The mapAccumL function behaves like a combination of map and foldl; it applies a function to each element of a ByteString, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new list.
The mapAccumL function behaves like a combination of map and foldl; it applies a function to each element of a ByteString, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new ByteString.
The mapAccumL function behaves like a combination of map and foldl; it applies a function to each element of a ByteString, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new list.
The mapAccumR function behaves like a combination of map and a strict foldr; it applies a function to each element of a Text, passing an accumulating parameter from right to left, and returning a final value of this accumulator together with the new Text. Performs replacement on invalid scalar values.
The mapAccumR function behaves like a combination of map and foldr; it applies a function to each element of a ByteString, passing an accumulating parameter from right to left, and returning a final value of this accumulator together with the new ByteString.
The mapAccumR function behaves like a combination of map and foldr; it applies a function to each element of a ByteString, passing an accumulating parameter from right to left, and returning a final value of this accumulator together with the new ByteString.
O(n). The function mapAccumR threads an accumulating argument through the map in descending order of keys.
O(n). The function mapAccumR threads an accumulating argument through the map in descending order of keys.
O(n). The function mapAccumWithKey threads an accumulating argument through the map in ascending order of keys. > let f a k b = (a ++ " " ++ (show k) ++ "-" ++ b, b ++ "X") > mapAccumWithKey f "Everything:" (fromList [(5,"a"), (3,"b")]) == ("Everything: 3-b 5-a", fromList [(3, "bX"), (5, "aX")])
O(n). The function mapAccumWithKey threads an accumulating argument through the map in ascending order of keys. > let f a k b = (a ++ " " ++ (show k) ++ "-" ++ b, b ++ "X") > mapAccumWithKey f "Everything:" (fromList [(5,"a"), (3,"b")]) == ("Everything: 3-b 5-a", fromList [(3, "bX"), (5, "aX")])
Constructs a new array derived from the original array by applying a function to each of the elements.
Apply a function to transform the result of a continuation-passing computation. *  (mapCont f m) = f . runCont
Apply a function to transform the result of a continuation-passing computation. *  (mapContT f m) = f . runContT
O(n). Map values and separate the Left and Right results. > let f a = if a < "c" then Left a else Right a > mapEither f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) > == (fromList [(3,"b"), (5,"a")], fromList [(1,"x"), (7,"z")]) > > mapEither (\ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) > == (empty, fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])
O(n). Map values and separate the Left and Right results. > let f a = if a < "c" then Left a else Right a > mapEither f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) > == (fromList [(3,"b"), (5,"a")], fromList [(1,"x"), (7,"z")]) > > mapEither (\ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) > == (empty, fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")])
O(n). Map keys/values and separate the Left and Right results. > let f k a = if k < 5 then Left (k * 2) else Right (a ++ a) > mapEitherWithKey f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) > == (fromList [(1,2), (3,6)], fromList [(5,"aa"), (7,"zz")]) > > mapEitherWithKey (\_ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) > == (empty, fromList [(1,"x"), (3,"b"), (5,"a"), (7,"z")])
O(n). Map keys/values and separate the Left and Right results. > let f k a = if k < 5 then Left (k * 2) else Right (a ++ a) > mapEitherWithKey f (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) > == (fromList [(1,2), (3,6)], fromList [(5,"aa"), (7,"zz")]) > > mapEitherWithKey (\_ a -> Right a) (fromList [(5,"a"), (3,"b"), (1,"x"), (7,"z")]) > == (empty, fromList [(1,"x"), (3,"b"), (5,"a"), (7,"z")])
Map the unwrapped computation using the given function. *  (mapErrorT f m) = f (runErrorT >
Lift a unary operation to the new monad.
Constructs a new array derived from the original array by applying a function to each of the indices.
O(n*min(n,W)). mapKeys f s is the map obtained by applying f to each key of s. The size of the result may be smaller if f maps two or more distinct keys to the same new key. In this case the value at the greatest of the original keys is retained. > mapKeys (+ 1) (fromList [(5,"a"), (3,"b")]) == fromList [(4, "b"), (6, "a")] > mapKeys (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "c" > mapKeys (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "c"
O(n*log n). mapKeys f s is the map obtained by applying f to each key of s. The size of the result may be smaller if f maps two or more distinct keys to the same new key. In this case the value at the greatest of the original keys is retained. > mapKeys (+ 1) (fromList [(5,"a"), (3,"b")]) == fromList [(4, "b"), (6, "a")] > mapKeys (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "c" > mapKeys (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "c"
O(n*min(n,W)). mapKeysMonotonic f s == mapKeys f s, but works only when f is strictly monotonic. That is, for any values x and y, if x < y then f x < f y. The precondition is not checked. Semi-formally, we have: > and [x < y ==> f x < f y | x <- ls, y <- ls] > ==> mapKeysMonotonic f s == mapKeys f s > This means that f maps distinct original keys to distinct resulting keys. This function has slightly better performance than mapKeys. > mapKeysMonotonic (\ k -> k * 2) (fromList [(5,"a"), (3,"b")]) == fromList [(6, "b"), (10, "a")]
O(n). mapKeysMonotonic f s == mapKeys f s, but works only when f is strictly monotonic. That is, for any values x and y, if x < y then f x < f y. The precondition is not checked. Semi-formally, we have: > and [x < y ==> f x < f y | x <- ls, y <- ls] > ==> mapKeysMonotonic f s == mapKeys f s > This means that f maps distinct original keys to distinct resulting keys. This function has better performance than mapKeys. > mapKeysMonotonic (\ k -> k * 2) (fromList [(5,"a"), (3,"b")]) == fromList [(6, "b"), (10, "a")] > valid (mapKeysMonotonic (\ k -> k * 2) (fromList [(5,"a"), (3,"b")])) == True > valid (mapKeysMonotonic (\ _ -> 1) (fromList [(5,"a"), (3,"b")])) == False
O(n*log n). mapKeysWith c f s is the map obtained by applying f to each key of s. The size of the result may be smaller if f maps two or more distinct keys to the same new key. In this case the associated values will be combined using c. > mapKeysWith (++) (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "cdab" > mapKeysWith (++) (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "cdab"
O(n*min(n,W)). mapKeysWith c f s is the map obtained by applying f to each key of s. The size of the result may be smaller if f maps two or more distinct keys to the same new key. In this case the associated values will be combined using c. > mapKeysWith (++) (\ _ -> 1) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 1 "cdab" > mapKeysWith (++) (\ _ -> 3) (fromList [(1,"b"), (2,"a"), (3,"d"), (4,"c")]) == singleton 3 "cdab"