Convert (docs.other.menhirLib.MenhirLib.Convert)

type ('token, 'semantic_value) traditional =
  (Lexing.lexbuf -> 'token) ->
  Lexing.lexbuf ->
  'semantic_value

An ocamlyacc-style, or Menhir-style, parser requires access to the lexer, which must be parameterized with a lexing buffer, and to the lexing buffer itself, where it reads position information.

This traditional API is convenient when used with ocamllex, but inelegant when used with other lexer generators.

type ('token, 'semantic_value) revised = (unit -> 'token) -> 'semantic_value

The revised API is independent of any lexer generator. Here, the parser only requires access to the lexer, and the lexer takes no parameters. The tokens returned by the lexer may contain position information.

val traditional2revised : 
  ('token -> 'raw_token) ->
  ('token -> Lexing.position) ->
  ('token -> Lexing.position) ->
  ('raw_token, 'semantic_value) traditional ->
  ('token, 'semantic_value) revised

traditional2revised converts a traditional parser, produced by ocamlyacc or Menhir, into a revised parser.

A token of the revised lexer is essentially a triple of a token of the traditional lexer (or raw token), a start position, and and end position. The three get functions are accessors.

We do not require the type 'token to actually be a triple type. This enables complex applications where it is a record type with more than three fields. It also enables simple applications where positions are of no interest, so 'token is just 'raw_token and get_startp and get_endp return dummy positions.

val revised2traditional : 
  ('raw_token -> Lexing.position -> Lexing.position -> 'token) ->
  ('token, 'semantic_value) revised ->
  ('raw_token, 'semantic_value) traditional

revised2traditional converts a revised parser to a traditional parser.

module Simplified : sig ... end

This submodule offers simplified versions of the above conversions. In this simplified API, concrete triples are used.