类型 Sedlexing.lexbuf 与类型 Lexing.lexbuf 不兼容

Question

我想通过 sedlex+menhir 将 menhir 的增量 API 和错误处理添加到我的项目中；我试图在我的代码中采用 attempt2 和 fail of this sample。这是示例的 attempt2：

let attempt2 filename text =
  (* Allocate and initialize a lexing buffer. *)
  let lexbuf = L.init filename (Lexing.from_string text) in
  (* Wrap the lexer and lexbuf together into a supplier, that is, a
     function of type [unit -> token * position * position]. *)
  let supplier = I.lexer_lexbuf_to_supplier Lexer.token lexbuf in
  (* Equip the supplier with a two-place buffer that records the positions
     of the last two tokens. This is useful when a syntax error occurs, as
     these are the token just before and just after the error. *)
  let buffer, supplier = E.wrap_supplier supplier in
  (* Fetch the parser's initial checkpoint. *)
  let checkpoint = UnitActionsParser.Incremental.main lexbuf.lex_curr_p in
  (* Run the parser. *)
  (* We do not handle [Lexer.Error] because we know that we will not
     encounter a lexical error during this second parsing run. *)
  I.loop_handle succeed (fail text buffer) supplier checkpoint

在我的代码中，我试过：

let lexbuf : Lexing.lexbuf = MenhirLib.LexerUtil.init "filename" (Lexing.from_string s) in
let supplier = UnitActionsParser_e.MenhirInterpreter.lexer_lexbuf_to_supplier Sedlexer_e.token_ao lexbuf in

但是编译报错：

260 |       let supplier = UnitActionsParser_e.MenhirInterpreter.lexer_lexbuf_to_supplier Sedlexer_e.token_ao lexbuf in
                                                                                          ^^^^^^^^^^^^^^^^^^^
Error: This expression has type Sedlexing.lexbuf -> Parser_e.token
       but an expression was expected of type
         Lexing.lexbuf -> UnitActionsParser_e.MenhirInterpreter.token
       Type Sedlexing.lexbuf is not compatible with type Lexing.lexbuf 
make: *** [expression/e.cmo] Error 2

有人能帮忙吗？

(* link 在 GitHub *)

Answer 1

lexer_lexbuf_to_supplier的代码如下：

  let lexer_lexbuf_to_supplier
      (lexer : Lexing.lexbuf -> token)
      (lexbuf : Lexing.lexbuf)
  : supplier =
    fun () ->
      let token = lexer lexbuf in
      let startp = lexbuf.Lexing.lex_start_p
      and endp = lexbuf.Lexing.lex_curr_p in
      token, startp, endp

所以我做了一个lexer_lexbuf_to_supplier_sedlex:

  let lexer_lexbuf_to_supplier_sedlex
    (lexer: Sedlexing.lexbuf -> token)
    (lexbuf : Sedlexing.lexbuf) 
  : supplier =
    fun () ->
      let token = lexer lexbuf in
      let startp, endp = Sedlexing.lexing_positions lexbuf in
      token, startp, endp

目前有效。

类型 Sedlexing.lexbuf 与类型 Lexing.lexbuf 不兼容

Type Sedlexing.lexbuf is not compatible with type Lexing.lexbuf

ocaml

menhir

sedlex