CamlinternalMenhirLib.LexerUtil(3) OCaml library CamlinternalMenhirLib.LexerUtil(3)

# [NAME](#NAME)

CamlinternalMenhirLib.LexerUtil - no description

# [Module](#Module)

Module CamlinternalMenhirLib.LexerUtil

# [Documentation](#Documentation)

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** . It is synonymous with **Lexing.new\_line 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** .

2026-10-23 OCamldoc

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Document: CamlinternalMenhirLib.LexerUtil(3o) from ocaml 5.5.2-r0 (Chainguard OS)
Source: https://github.com/ocaml/ocaml