foldl' is:exact -package:containers -package:base -package:text -package:vector
foldl' is like foldl, but strict in the accumulator.
Reduce this map by applying a binary operator to all
elements, using the given starting value (typically the left-identity
of the operator). Each application of the operator is evaluated before
using the result in the next application. This function is strict in
the starting value.
Reduce this set by applying a binary operator to all
elements, using the given starting value (typically the left-identity
of the operator). Each application of the operator is evaluated before
before using the result in the next application. This function is
strict in the starting value.
Left-associative fold of a structure but with strict application of
the operator.
This ensures that each step of the fold is forced to Weak Head Normal
Form before being applied, avoiding the collection of thunks that
would otherwise occur. This is often what you want to strictly reduce
a finite structure to a single strict result (e.g.
sum).
For a general
Foldable structure this should be semantically
identical to,
foldl' f z = foldl' f z . toList
Strict left fold of the metadatas
Strict left fold over all key-value pairs in the headers map.
Example:
ghci> :set -XOverloadedStrings
ghci> import Data.Monoid
ghci> let hdrs = H.fromList [("Accept", "text/plain"), ("Accept", "text/html")]
ghci> let f (cntr, acc) _ val = (cntr+1, val <> ";" <> acc)
ghci> H.foldl' f (0, "") hdrs
(2,"text/html;text/plain;")
Left-associative fold of a structure but with strict application of
the operator.
This ensures that each step of the fold is forced to weak head normal
form before being applied, avoiding the collection of thunks that
would otherwise occur. This is often what you want to strictly reduce
a finite list to a single, monolithic result (e.g.
length).
For a general
Foldable structure this should be semantically
identical to,
foldl' f z = foldl' f z . toList
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. Subject to fusion.
O(n) Left fold with strict accumulator
O(n) Left fold with strict accumulator
O(n) Left fold with strict accumulator
O(n) Left fold with strict accumulator
Left associative/strict push fold. foldl' reduce initial
stream invokes reduce with the accumulator and the next
input in the input stream, using initial as the initial value
of the current value of the accumulator. When the input is exhausted
the current value of the accumulator is returned. Make sure to use a
strict data structure for accumulator to not build unnecessary lazy
expressions unless that's what you want. See the previous section for
more details.
Strict left associative fold.
Left fold over bytes, strict in the accumulator.