foldr package:ghc

Fold the values in the map using the given right-associative binary operator, such that foldr f z == foldr f z . elems. For example,

elems map = foldr (:) [] map

let f a len = len + (length a)
foldr f 0 (fromList [(5,"a"), (3,"bbb")]) == 4

Fold the elements in the set using the given right-associative binary operator, such that foldr f z == foldr f z . toAscList. For example,

toAscList set = foldr (:) [] set

Folds backward over all the nodes of an open-open block and allows rewriting them. The accumulator is both the block of nodes and f (usually dataflow facts). Strict in both accumulated parts.

A strict version of foldr. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.

Fold the keys and values in the map using the given right-associative binary operator, such that foldrWithKey f z == foldr (uncurry f) z . toAscList. For example,

keys map = foldrWithKey (\k x ks -> k:ks) [] map

let f k a result = result ++ "(" ++ (show k) ++ ":" ++ a ++ ")"
foldrWithKey f "Map: " (fromList [(5,"a"), (3,"b")]) == "Map: (5:a)(3:b)"

A strict version of foldrWithKey. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.

A strict version of foldr. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.