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Equivalent of Quotation.ExStr in new camlp4?
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Date: 2007-07-26 (16:49)
From: Harrison, John R <john.r.harrison@i...>
Subject: RE: [Caml-list] Equivalent of Quotation.ExStr in new camlp4?
Trying your example in 3.10.0, I get the following:

| $ ocamlc -pp camlp4of -I +camlp4 -c ex_str.ml
| File "ex_str.ml", line 2, characters 2-24:
| Unbound module Camlp4OCamlParser.Make

I get a similar error in the toplevel even after #load "camlp4o.cma".
Do I need to load and/or open something else?


-----Original Message-----
From: Nicolas Pouillard [mailto:nicolas.pouillard@gmail.com] 
Sent: Thursday, July 26, 2007 1:44 AM
To: Harrison, John R
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Equivalent of Quotation.ExStr in new camlp4?

On 7/25/07, Harrison, John R <john.r.harrison@intel.com> wrote:
> | No ExStr is no more supported. But you can do it your self by
> | the parser on your string if you really don't want switch to an AST
> | based quotation expander.
> OK, that's fine. But how do I do that? Concretely, this is what I had
> before, so what should I have now?
>   Quotation.add "" (Quotation.ExStr (fun x -> quotexpander));;
> I don't mind in principle writing an AST-producing expander, but at
> moment the priority is to get my code working in 3.10 with minimal
> expenditure of effort.

You can instanciate an OCaml parser that way:

$ cat ex_str.mlmodule Caml =

let quotexpander str =
  "[1; 2; 3]" (* ... do some real code on str *)

let patt_quotexpander loc _loc_name_opt str =
  Gram.parse_string Caml.patt loc (quotexpander str)

let expr_quotexpander loc _loc_name_opt str =
  Gram.parse_string Caml.expr loc (quotexpander str)

let str_item_quotexpander loc loc_name_opt str =
  <:str_item@loc< $exp: expr_quotexpander loc loc_name_opt str$ >>

let () =
  Syntax.Quotation.add "" Syntax.Quotation.DynAst.expr_tag
  Syntax.Quotation.add "" Syntax.Quotation.DynAst.str_item_tag
  Syntax.Quotation.add "" Syntax.Quotation.DynAst.patt_tag

$ ocamlc -pp camlp4of -I +camlp4 -c ex_str.ml
$ camlp4o ./ex_str.cmo -str '<<>>;;'


Nicolas Pouillard