Re: [Caml-list] infix precedence

[dengping zhu <zhudp@cs.bu.edu>]

I tried camlp4 before. I got the example from the camlp4 tutorial and
modified a little bit. 

The code is as follows:
---------------------------------------------
let gram = Grammar.create (Plexer.make());;
let expr = Grammar.Entry.create gram "expr";;

EXTEND
  expr:
      [ "1" LEFTA [] | "2" LEFTA []];
END;;

let add_infix lev op =
         EXTEND
           GLOBAL: expr;
           expr: LEVEL $lev$
            [ [ x = expr; $op$; y = expr -> <:expr< $lid:op$ $x$ $y$ >> ] ];
         END;;
-------------------------------------------------------------------

After I compile it in ocaml 

# #use "foo.ml";;

I can use the function 'add_infix':
# add_infix "1" "op1";;

But how can I use the infix "op1" later? 
I tried to use as follows:

#let op1 x y = x + y;;
#Grammar.Entry.parse expr ( Stream.of_string "x op1 y");;

But I got an error. 

Can someboday pass an example for me?

Thanks!




On Tue, 28 May 2002, Daniel de Rauglaudre wrote:

>Hi,
>
>On Tue, May 28, 2002 at 02:16:12PM -0400, dengping zhu wrote:
>
>> Hi, John, thanks for your help.  Hope I could solve it today.
>> Anyway, I think that Ocaml should support infix as SML.
>
>Camlp4
>
>-- 
>Daniel de RAUGLAUDRE
>daniel.de_rauglaudre@inria.fr
>http://cristal.inria.fr/~ddr/
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