Module Parsexp.Eager_just_positions

Same as Parser but gives back a s-expression as soon as they are found in the input.

For instance you can use this function to parse a stream and stop at the first s-expression:

        exception Got_sexp of Sexp.t

        let fetch_sexp stream =
          let module P = Parsexp.Sexp_parsing.Eager in
          let rec hot_loop state stream stack =
            match Stream.peek stream with
            | None -> P.feed_eoi state stack
            | Some char ->
              let stack = P.feed state char stack in
              Stream.junk stream;
              hot_loop state stream stack
          in
          let got_sexp state sexp =
            raise_notrace (Got_sexp sexp)
          in
          let count = Stream.count stream in
          let state = P.State.create ~f:got_sexp ~no_sexp_is_error:true in
          match hot_loop state stream P.Stack.empty with
          | () -> assert false
          | exception (Got_sexp sexp) ->
            (* This test is true if the s-expression includes the last character passed to
               the parser *)
            if P.State.offset state > Stream.count stream - count then Stream.junk stream;
            sexp