OCaml compiler library : CamlinternalMenhirLib.LexerUtil

# Module CamlinternalMenhirLib.LexerUtil

    module LexerUtil: sig .. end

    val init : string -> Lexing.lexbuf -> Lexing.lexbuf

`init filename lexbuf` initializes the lexing buffer `lexbuf` so that the positions that are subsequently read from it refer to the file `filename`. It returns `lexbuf`.

    val read : string -> string * Lexing.lexbuf

`read filename` reads the entire contents of the file `filename` and returns a pair of this content (a string) and a lexing buffer that has been initialized, based on this string.

    val newline : Lexing.lexbuf -> unit

`newline lexbuf` increments the line counter stored within `lexbuf`. It should be invoked by the lexer itself every time a newline character is consumed. This allows maintaining a current the line number in `lexbuf`.

    val range : Lexing.position * Lexing.position -> string

`range (startpos, endpos)` prints a textual description of the range delimited by the start and end positions `startpos` and `endpos`. This description is one line long and ends in a newline character. This description mentions the file name, the line number, and a range of characters on this line. The line number is correct only if `newline` has been correctly used, as described dabove.

    val tabulate : ('a -> bool) -> (unit -> 'a) -> unit -> 'a

`tabulate is_eof lexer` tabulates the lexer `lexer`: that is, it immediately runs this lexer all the way until an EOF token is found, stores the tokens in an array in memory, and returns a new lexer which (when invoked) reads tokens from this array. The function `lexer` is not allowed to raise an exception, and must produce a finite stream of tokens: that is, after a finite number of invocations, it must return a token that is identified by the function `is_eof` as an EOF token.

Both the existing lexer `lexer` and the new lexer returned by `tabulate
is_eof lexer` are functions of type `unit -> 'a`, where the type `'a` is likely to be instantiated with a triple of a token and two positions, as per the revised lexer API described in the module `CamlinternalMenhirLib.Convert`.