**foldl** -bytestring -package -syb

foldl, applied to a binary operator, a starting value (typically the left-identity of the operator), and a list, reduces the list using the binary operator, from left to right:
> foldl f z [x1, x2, ..., xn] == (...((z `f` x1) `f` x2) `f`...) `f` xn
The list must be finite.
*O(n)* foldl, applied to a binary operator, a starting value (typically the left-identity of the operator), and a Text, reduces the Text using the binary operator, from left to right. Subject to fusion.
*O(n)*. Fold the elements in the set using the given left-associative binary operator, such that foldl f z == foldl f z . toAscList.
For example,
> toDescList set = foldl (flip (:)) [] set
*O(n)*. Fold the values in the map using the given left-associative binary operator, such that foldl f z == foldl f z . elems.
For example,
> elems = reverse . foldl (flip (:)) []
> let f len a = len + (length a)
> foldl f 0 (fromList [(5,"a"), (3,"bbb")]) == 4
*O(n)*. Fold the values in the map using the given left-associative binary operator, such that foldl f z == foldl f z . elems.
For example,
> elems = reverse . foldl (flip (:)) []
> let f len a = len + (length a)
> foldl f 0 (fromList [(5,"a"), (3,"bbb")]) == 4
*O(n)*. Fold the elements in the set using the given left-associative binary operator, such that foldl f z == foldl f z . toAscList.
For example,
> toDescList set = foldl (flip (:)) [] set
foldl1 is a variant of foldl that has no starting value argument, and thus must be applied to non-empty lists.
A strict version of foldl.
Fold over the elements of a structure, associating to the left, but strictly.

Monadic fold over the elements of a structure, associating to the left, i.e. from left to right.

*O(n)* A strict version of foldl. Subject to fusion.
*O(n)*. A strict version of foldl. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.
*O(n)*. A strict version of foldl. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.
*O(n)*. A strict version of foldl. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.
*O(n)*. A strict version of foldl. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.
*O(n)* A variant of foldl that has no starting value argument, and thus must be applied to a non-empty Text. Subject to fusion.
*O(n)* A strict version of foldl1. Subject to fusion.
Consume the chunks of a lazy Text with a strict, tail-recursive, accumulating left fold.
*O(n)*. Fold the keys and values in the map using the given left-associative binary operator, such that foldlWithKey f z == foldl (\z' (kx, x) -> f z' kx x) z . toAscList.
For example,
> keys = reverse . foldlWithKey (\ks k x -> k:ks) []
> let f result k a = result ++ "(" ++ (show k) ++ ":" ++ a ++ ")"
> foldlWithKey f "Map: " (fromList [(5,"a"), (3,"b")]) == "Map: (3:b)(5:a)"
*O(n)*. Fold the keys and values in the map using the given left-associative binary operator, such that foldlWithKey f z == foldl (\z' (kx, x) -> f z' kx x) z . toAscList.
For example,
> keys = reverse . foldlWithKey (\ks k x -> k:ks) []
> let f result k a = result ++ "(" ++ (show k) ++ ":" ++ a ++ ")"
> foldlWithKey f "Map: " (fromList [(5,"a"), (3,"b")]) == "Map: (3:b)(5:a)"
*O(n)*. A strict version of foldlWithKey. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.
*O(n)*. A strict version of foldlWithKey. Each application of the operator is evaluated before using the result in the next application. This function is strict in the starting value.