Re: js_of_ocaml and ocamllex

Le 21/11/2015 20:02, Sébastien Dailly [email protected]
[ocaml_beginners] a écrit :
>  
> 
> Hello,
> 
> I'm looking for a documentation for js_of_ocaml
> 
> - Reading a local file with the File api
> - Send the data to ocamllex/menhir
> 
> is there some examples available ?
> 

Hello,

I'm trying to experiment Lexer and refill function but does not
understand how it works :

I've used the example provided by the document :

> {
> type token = EOL | INT of int | PLUS
> 
> module Make (M : sig
> type 'a t
> val return: 'a -> 'a t
> val bind: 'a t -> ('a -> 'b t) -> 'b t
> val fail : exn -> 'a t
> 
> (* Set up lexbuf *)
> val on_refill : Lexing.lexbuf -> unit t
> end)
> = struct
> 
> let refill_handler k lexbuf arg =
> M.bind (M.on_refill lexbuf) (fun () -> k lexbuf arg)
> 
> }
> 
> refill {refill_handler}
> 
> rule token = parse
> | [' ' '\t']
> { token lexbuf }
> | '\n'
> { M.return EOL }
> | ['0'-'9']+ as i
> { M.return (INT (int_of_string i)) }
> | '+'
> { M.return PLUS }
> | _
> { M.fail (Failure "unexpected character") }
> {
> end
> }

with a simple example :

main.ml :
> 
> module L = Lexer.Make(struct
> include Lwt
> 
> let on_refill lexer =
> Lwt.return_unit
> 
> end)

But this does not compile, and I don't understand this error message :

$ ocamlbuild -pkgs lwt main.native
File "lexer.ml", line 152, characters 9-55:
Error: This expression has type token M.t
       but an expression was expected of type 'a -> 'b M.t

What did I did wrong ? It seems that the errors comes from the generated
lexer.

Thanks for your help !

-- 
Sébastien