intersperse package:streamly-core

Insert a pure value between successive elements of a stream. It does nothing if stream has less than two elements. Definition:

>>> intersperse x = Stream.intersperseM (return x)

>>> intersperse x = Stream.unfoldEachSepBy x Unfold.identity

>>> intersperse x = Stream.unfoldEachSepBySeq x Unfold.identity

>>> intersperse x = Stream.interleaveSepBy (Stream.repeat x)

Example:

>>> f x y = Stream.toList $ Stream.intersperse x $ Stream.fromList y

>>> f ',' "abc"
"a,b,c"

>>> f ',' "a"
"a"

Effectful variant of intersperse. Insert an effect and its output between successive elements of a stream. It does nothing if stream has less than two elements. Definition:

>>> intersperseM x = Stream.interleaveSepBy (Stream.repeatM x)

Perform a side effect between two successive elements of a stream. It does nothing if the stream has less than two elements.

>>> f x y = Stream.fold Fold.drain $ Stream.trace putChar $ Stream.intersperseM_ x $ Stream.fromList y

>>> f (putChar '.') "abc"
a.b.c

>>> f (putChar '.') "a"
a

Pre-release

Insert a side effect before every element of a stream. Definition:

>>> intersperseBeginByM_ = Stream.trace_

>>> intersperseBeginByM_ m = Stream.mapM (\x -> void m >> return x)

Usage:

>>> f x y = Stream.fold Fold.drain $ Stream.trace putChar $ Stream.intersperseBeginByM_ x $ Stream.fromList y

>>> f (putChar '.') "abc"
.a.b.c

Same as trace_. Pre-release

Like intersperseEndByM but intersperses an effectful action into the input stream after every n elements and also after the last element. Example:

>>> input = Stream.fromList "hello"

>>> Stream.toList $ Stream.intersperseEndByEveryM 2 (return ',') input
"he,ll,o,"

>>> f n x y = Stream.toList $ Stream.intersperseEndByEveryM n (pure x) $ Stream.fromList y

>>> f 2 ',' "abcdef"
"ab,cd,ef,"

>>> f 2 ',' "abcdefg"
"ab,cd,ef,g,"

>>> f 2 ',' "a"
"a,"

Pre-release

Insert an effect and its output after every element of a stream. Definition:

>>> intersperseEndByM x = Stream.interleaveEndBy (Stream.repeatM x)

Usage:

>>> f x y = Stream.toList $ Stream.intersperseEndByM (pure x) $ Stream.fromList y

>>> f ',' "abc"
"a,b,c,"

>>> f ',' "a"
"a,"

Pre-release

Insert an effect after every element of a stream. Example:

>>> f x y = Stream.fold Fold.drain $ Stream.trace putChar $ Stream.intersperseEndByM_ x $ Stream.fromList y

>>> f (putChar '.') "abc"
a.b.c.

>>> f (putChar '.') "a"
a.

Pre-release

Intersperse a monadic action into the input stream after every n elements. Definition:

> intersperseEveryM n x = Stream.interleaveEverySepBy n (Stream.repeatM x)

Idioms:

>>> intersperseM = Stream.intersperseEveryM 1

>>> intersperse x = Stream.intersperseEveryM 1 (return x)

Usage:

> input = Stream.fromList "hello"
> Stream.toList $ Stream.intersperseEveryM 2 (return ',') input

"he,ll,o" Unimplemented

Deprecated: Please use intersperseBeginByM_ instead.

Deprecated: Please use intersperseEndByM instead.

Deprecated: Please use intersperseEndByEveryM instead.

Deprecated: Please use intersperseEndByM_ instead.