filter -package:base -package:unordered-containers -package:hedgehog -package:conduit -package:aeson -package:ghc
O(n) filter, applied to a predicate and a ByteString,
returns a ByteString containing those characters that satisfy the
predicate.
O(n) filter, applied to a predicate and a ByteString,
returns a ByteString containing those characters that satisfy the
predicate.
O(n) filter, applied to a predicate and a
ShortByteString, returns a ShortByteString containing those characters
that satisfy the predicate.
O(n) filter, applied to a predicate and a
Text,
returns a
Text containing those characters that satisfy the
predicate.
O(n) filter, applied to a predicate and a stream,
returns a stream containing those characters that satisfy the
predicate.
Properties
unstream . filter p . stream = filter p
Filter all values that satisfy some predicate.
filter (> "a") (fromList [(5,"a"), (3,"b")]) == singleton 3 "b"
filter (> "x") (fromList [(5,"a"), (3,"b")]) == empty
filter (< "a") (fromList [(5,"a"), (3,"b")]) == empty
Filter all elements that satisfy some predicate.
Filter all values that satisfy the predicate.
filter (> "a") (fromList [(5,"a"), (3,"b")]) == singleton 3 "b"
filter (> "x") (fromList [(5,"a"), (3,"b")]) == empty
filter (< "a") (fromList [(5,"a"), (3,"b")]) == empty
The
filter function takes a predicate
p
and a sequence
xs and returns a sequence of those elements
which satisfy the predicate.
Filter all elements that satisfy the predicate.
O(n) Drop all elements that do not satisfy the predicate.
Drop elements which do not satisfy the predicate
Drop elements which do not satisfy the predicate
O(n) Drop all elements that do not satisfy the predicate.
O(n) Drop all elements that do not satisfy the predicate.
O(n) Drop all elements that do not satisfy the predicate.
O(n) Drop all elements that do not satisfy the predicate.
filter, applied to a predicate and a list,
returns the list of those elements that satisfy the predicate; i.e.,
filter p xs = [ x | x <- xs, p x]
>>> filter odd [1, 2, 3]
[1,3]
(filter predicate) only forwards values that satisfy the
predicate.
filter (pure True) = cat
filter (liftA2 (&&) p1 p2) = filter p1 >-> filter p2
filter f = mapMaybe (\a -> a <$ guard (f a))
filter p xs removes any elements from
xs that
do not satisfy
p.
Drops chunks from an input stream if they fail to match a given filter
predicate. See
filter.
Items pushed back to the returned stream are propagated back upstream.
Example:
ghci> Streams.fromList ["the", "quick", "brown", "fox"] >>=
Streams.filter (/= "brown") >>= Streams.toList
["the","quick","fox"]