Stream (bytesrw.Bytesrw.Bytes.Stream)

Positions

type pos = int

The type for stream positions.

The position of a stream is the zero-based byte index of the next byte to read or write. It can also be seen as the count of bytes read or written by a stream reader or writer.

Formats

type format = string

The type for stream formats. An identifier for the format of read or written bytes. Favour mime types or lowercased file extensions without the dot.

Errors

Read more about errors in the tutorial.

type error = ..

The type for stream errors. Stream formats add their own cases to this type. See an example.

type error_context

The type for error contexts.

exception Error of error * error_context

The exception raised by streams reader, writers and their creation functions.

val error_message : (error * error_context) -> string

error_message e turns error e into an error message for humans.

val error_to_result : (error * error_context) -> ('a, string) Stdlib.result

error_to_result e is Result.Error (error_message e).

type 'e format_error

The type for describing errors of type 'e for a stream format.

val make_format_error : 
  format:format ->
  case:('e -> error) ->
  message:(error -> string) ->
  'e format_error

make_format_error ~format ~case ~message describes the type of error for format format:

format identifies the stream format.
case is the function that injects the type into error.
message is a function that must stringify the results of case.

See an example.

val error : 'e format_error -> ?context:[ `R | `W ] -> 'e -> 'a

error fmt e errors with e for a stream fmt by raising an Error exception.

Limits

type error +=

| Limit of int
(*
The inclusive byte count limit.
*)

The type for stream limits errors.

val limit_error : int format_error

limit_error is a stream limit error.