package batteries

Raised by parsers when none of the first components of the stream patterns is accepted.

Raised by parsers when the first component of a stream pattern is accepted, but one of the following components is rejected.

Stream.from f returns a stream built from the function f. To create a new stream element, the function f is called with the current stream count. The user function f must return either Some <value> for a value or None to specify the end of the stream.

Return the stream holding the elements of the list in the same order.

Return the stream of the characters of the string parameter.

Return the stream of the characters of the bytes parameter.

• since 2.3.0

Return the stream of the characters read from the input channel.

Stream.of_fun f returns a stream built from the function f. To create a new stream element, the function f is called with the current stream count. The user function f must return either Some <value> for a value or None to specify the end of the stream.

Stream.iter f s scans the whole stream s, applying function f in turn to each stream element encountered.

foldl f init stream is a lazy fold_left. f accu elt should return (new_accu, state) where new_accu is normal accumulation result, and state is a flag representing whether the computation should continue and whether the last operation is valid: None means continue, Some b means stop where b = true means the last addition is still valid and b = false means the last addition is invalid and should be revert.

foldr f init stream is a lazy fold_right. Unlike the normal fold_right, the accumulation parameter of f elt accu is lazy, hence it can decide not to force the evaluation of accu if the current element elt can determine the result by itself.

fold is foldl without initialization value, where the first element of stream is taken as init. It raises End_of_stream exception when the input stream is empty.

filter test stream picks all the elements satisfying test from stream and return the results in the same order as a stream.

Return () if the stream is empty, else raise Stream.Failure.

Return Some of "the first element" of the stream, or None if the stream is empty.

Remove the first element of the stream, possibly unfreezing it before.

Return the current count of the stream elements, i.e. the number of the stream elements discarded.

npeek n returns the list of the n first elements of the stream, or all its remaining elements if less than n elements are available.

Convert a stream to an enumeration. Reading the resulting enumeration will consume elements from the stream. This is the preferred manner of converting from a stream to any other data structure.

Convert an enumeration to a stream. Reading the resulting stream will consume elements from the enumeration. This is the preferred manner of creating a stream.

Convert an input to a stream.

Convert a stream to a list

convert stream of chars to string, using buffer

convert stream to string, using Printf with given format

convert stream to string, using given conversion function

Convert an output to a stream.

map f stream applies f in turn to elements from stream and return the results as a stream in the same order.

map2 f streama streamb applies f in turn to elements of corresponding positions from streama and streamb. The results are constructed in the same order as a stream. If one stream is short, excess elements of the longer stream are ignored.

scanl f init stream returns a stream of successive reduced values from the left: scanl f init [< 'e0; 'e1; ... >] is equivalent to [< 'init; '(f init e0); '(f (f init e0) e1); ... >]

scan is similar to scanl but without the init value: scanl f init [< 'e0; 'e1; 'e2; ... >] is equivalent to [< 'e0; '(f e0 e1); '(f (f e0 e1) e2); ... >]

concatenate a stream of streams

Composition of concat and map. concat_map f e is the same as concat (map f e).

• since 2.3.0

take n stream returns the prefix of stream of length n, or stream itself if n is greater than the length of stream

drop n stream returns the suffix of stream after the first n elements, or a empty stream if n is greater than the length of stream

take_while test stream returns the longest (possibly empty) prefix of stream of elements that satisfy test.

drop_while test stream returns the remaining suffix of take_while test stream.

dup stream returns a pair of streams which are identical to stream. Note that stream is a destructive data structure, the point of dup is to return two streams can be used independently.

NOT IMPLEMENTED CORRECTLY - WILL RAISE Failure UNTIL CORRECT IMPLEMENTATION FOUND

comb transform a pair of stream into a stream of pairs of corresponding elements. If one stream is short, excess elements of the longer stream are ignored.

split is the opposite of comb

merge test (streama, streamb) merge the elements from streama and streamb into a single stream. The bool type here represents the id of the two input streams where true is the first and false represents the second. The test function is applied to each element of the output stream together with the id of the input stream from which it was extracted, to decide which stream should the next element come from. The first element is always taken from streama. When a stream runs out of elements, the merge process will continue to take elements from the other stream until both streams reach their ends.

switch test stream split stream into two streams, where the first stream have all the elements satisfying test, the second stream is opposite. The order of elements in the source stream is preserved.

cons x stream equals [<'x; stream>].

apnd fla flb equals [<fla;flb>].

is_empty stream tests whether stream is empty. But note that it forces the evaluation of the head element if any.

Return the first element of the stream and remove it from the stream.

• raises Stream.Failure

  if the stream is empty.

Note This module is provided essentially for backwards-compatibility. If you feel like using Stream.t, please take a look at BatEnum or LazyList and GenParser.