Re: [Caml-list] quasiquoting: 3 parsers for camlp4 vs 1 for haskell?
Excerpts from Jon Harrop's message of Thu Apr 23 01:19:09 +0200 2009: On Friday 17 April 2009 19:24:31 Joel Reymont wrote: From the quasiquoting paper by Geoffrey Mainland [1], page 7: The major advantage of our approach over that of camlp4 is that we demonstrate how to use generic programming to reuse a single parser to parse quasiquoted patterns, quasiquoted expressions and plain syntax that does not include antiquotes. Because OCaml does not support generic programming out of the box, I have no idea what he meant by this. in camlp4 this would require three separate parsers, AFAICT, that was not true when he wrote it (Sept 2007) and is not true today. There was indeed three different parsers for OCaml-like syntax in the old camlp4. Actually there was one classical parser for the official/original OCaml syntax but this one was not embeddable in quotations. There was also two parsers for the revised syntax one being the classical one and the other being for quotations. each generating different representations of the same concrete syntax. That has never been true. We are talking about quotations here, and I can confirm that the two parsers for the revised syntax where generating to different representations of the concrete syntax. Example (simplified): f 42 = App (Var f) (Int 42) f 42 = App (App (Con Var) (Str f)) (App (Con Int) (Str 42)) The new version of camlp4 use only one grammar for the revised syntax (instead of two) and a grammar extension for the official/original syntax. Best regards, -- Nicolas Pouillard ___ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
Re: [Caml-list] quasiquoting: 3 parsers for camlp4 vs 1 for haskell?
On Friday 17 April 2009 19:24:31 Joel Reymont wrote: From the quasiquoting paper by Geoffrey Mainland [1], page 7: The major advantage of our approach over that of camlp4 is that we demonstrate how to use generic programming to reuse a single parser to parse quasiquoted patterns, quasiquoted expressions and plain syntax that does not include antiquotes. Because OCaml does not support generic programming out of the box, I have no idea what he meant by this. in camlp4 this would require three separate parsers, AFAICT, that was not true when he wrote it (Sept 2007) and is not true today. each generating different representations of the same concrete syntax. That has never been true. Can someone shed light on how, where and why three different parsers are required for camlp4? I've CC'd the author. Perhaps he can shed some light on this. -- Dr Jon Harrop, Flying Frog Consultancy Ltd. http://www.ffconsultancy.com/?e ___ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
Re: [Caml-list] quasiquoting: 3 parsers for camlp4 vs 1 for haskell?
On Thu, Apr 23, 2009 at 12:19:09AM +0100, Jon Harrop wrote: On Friday 17 April 2009 19:24:31 Joel Reymont wrote: From the quasiquoting paper by Geoffrey Mainland [1], page 7: The major advantage of our approach over that of camlp4 is that we demonstrate how to use generic programming to reuse a single parser to parse quasiquoted patterns, quasiquoted expressions and plain syntax that does not include antiquotes. Because OCaml does not support generic programming out of the box, I have no idea what he meant by this. in camlp4 this would require three separate parsers, AFAICT, that was not true when he wrote it (Sept 2007) and is not true today. each generating different representations of the same concrete syntax. That has never been true. Can someone shed light on how, where and why three different parsers are required for camlp4? I've CC'd the author. Perhaps he can shed some light on this. I actually spoke with Nicolas Pouillard about this at the workshop, and he informed me that his rewrite of camlp4 for the 3.10 release included a facility for translating a value into an OCaml AST representing that value, so yes, that statement is now incorrect. I think Jake Donham's reply to Joel's message of 4/15 made this clear and even helpfully pointed to some code. As for my work, I hope that anyone reading the paper will find the technique I used to provide this functionality in the Haskell implementation of quasiquotation both elegant and easy to understand. Geoff ___ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
Re: [Caml-list] quasiquoting: 3 parsers for camlp4 vs 1 for haskell?
On Fri, Apr 17, 2009 at 11:24 AM, Joel Reymont joe...@gmail.com wrote: Can someone shed light on how, where and why three different parsers are required for camlp4? Is this still the case with 3.11? I haven't read the Mainland paper so I don't know exactly what he's talking about, but with the MetaGenerator module in Camlp4 you can use one parser for all three tasks. Antiquotations can be used in pattern matching (you can see this all over the Camlp4 source for the OCaml AST). Don't be misled by my jsgen.ml; it's just not finished. Jake ___ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
