Module Stream

include module type of struct include Stream end
type 'a t = 'a Stream.t

The type of streams holding values of type 'a.

exception Failure

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

exception Error of string

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

Stream builders

val from : (int -> 'a option) -> 'a t

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.

Do note that the indices passed to f may not start at 0 in the general case. For example, [< '0; '1; Stream.from f >] would call f the first time with count 2.

val of_list : 'a list -> 'a t

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

val of_string : string -> char t

Return the stream of the characters of the string parameter.

val of_bytes : bytes -> char t

Return the stream of the characters of the bytes parameter.

  • since 4.02.0
val of_channel : in_channel -> char t

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

Stream iterator

val iter : ('a -> unit) -> 'a t -> unit

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

Predefined parsers

val next : 'a t -> 'a

Return the first element of the stream and remove it from the stream. Raise Stream.Failure if the stream is empty.

val empty : 'a t -> unit

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

Useful functions

val peek : 'a t -> 'a option

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

val junk : 'a t -> unit

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

val count : 'a t -> int

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

val npeek : int -> 'a t -> 'a list

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.