# Module Lexer

    module Lexer: sig .. end

    val init : unit -> unit

    val token : Lexing.lexbuf -> Parser.token

    val skip_sharp_bang : Lexing.lexbuf -> unit

    type error =

`|` | `Illegal_character of `char``
`|` | `Illegal_escape of `string``
`|` | `Unterminated_comment of `Location.t``
`|` | `Unterminated_string`
`|` | `Unterminated_string_in_comment of `Location.t * Location.t``
`|` | `Keyword_as_label of `string``
`|` | `Invalid_literal of `string``

    exception Error of error * Location.t

    val report_error : Format.formatter -> error -> unit

    val in_comment : unit -> bool

    val in_string : unit -> bool

    val print_warnings : bool ref

    val handle_docstrings : bool ref

    val comments : unit -> (string * Location.t) list

    val token_with_comments : Lexing.lexbuf -> Parser.token

    val set_preprocessor : (unit -> unit) ->
           ((Lexing.lexbuf -> Parser.token) -> Lexing.lexbuf -> Parser.token) -> unit