[Caml-list] two bugs in camlp4? Help!!

[Caml-list] two bugs in camlp4? Help!!

[bob zhang]

Hi, all,
I am not sure that I made a mistake or two minor bugs in camlp4 revised
syntax?

Both cases are in toploop, after I type

#camlp4r;;
#load "camlp4rf.cma";
Register.loaded_modules;
- : ref (list string) =
{Pervasives.contents=
["Camlp4ListComprenhsion"; "Camlp4MacroParser"; "Camlp4MacroParser";
"Camlp4GrammarParser"; "Camlp4OCamlRevisedParserParser";
"Camlp4QuotationExpander"; "Camlp4OCamlRevisedParser"]}


case1:
for the signature parsing,

when I type
value x ~num(num=3) y = num > 0 ;
--> value x: ~?num:int -> bool

However, the signature can not be parsed by Camlp4
value parse_sig = Camlp4.PreCast.Syntax.(Gram.parse_string sig_item
Loc.ghost);

parse_sig "value x : ~?num:int -> bool;" will raie an exception
however, I tried parse_sig "value x : ?num:int -> bool ;", it's ok,

- : Camlp4.PreCast.Syntax.Ast.sig_item =
Camlp4.PreCast.Syntax.Ast.SgVal <abstr> "x"
(Camlp4.PreCast.Syntax.Ast.TyArr <abstr>
(Camlp4.PreCast.Syntax.Ast.TyOlb <abstr> "num"
(Camlp4.PreCast.Syntax.Ast.TyId <abstr>
(Camlp4.PreCast.Syntax.Ast.IdLid <abstr> "int")))
(Camlp4.PreCast.Syntax.Ast.TyId <abstr>
(Camlp4.PreCast.Syntax.Ast.IdLid <abstr> "bool")))
case 2:
when I type
module X = struct type a = int and b = (int * int); end;
in the toploop
module X : sig type a = int; and b = (int * int); end
you can see the semi is redudant, it is an error?

I thought Camlp4 was heavily used in bootstrapping itself, did I make
some stupid assumptions??

Thanks

Re: [Caml-list] two bugs in camlp4? Help!!

[Gabriel Scherer]

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>
> when I type
> value x ~num(num=3) y = num > 0 ;
>
--> value x: ~?num:int -> bool
>
> However, the signature can not be parsed by Camlp4

however, I tried parse_sig "value x : ?num:int -> bool ;", it's ok,
>

This seems to be a bug in the printer.
(By the way, it is not useful to declare an optional argument as last
parameter of a function, because it cannot be erased. You will have to pass
it explicitely (otherwise caml couldn't make the difference between writing
the function and writing the function application, writing (x ~num:None) to
get the default value).

 module X : sig type a = int; and b = (int * int); end
> you can see the semi is redudant, it is an error?
>

Again, this looks like a printer issue. The correct syntax has no semicolon
before "and":  (type .. and .. and ...) is a single phrase.

For a relatively comprehensive documentation of the revised syntax¹, see
  http://caml.inria.fr/pub/docs/tutorial-camlp4/tutorial005.html
(This is the revised syntax as of camlp4 < 3.10, and possibly Camlp5; in
current versions of Camlp4 I think the rules have been slightly relaxed, but
that it is backward-compatible.)

2011/5/9 bob zhang <bobzhang1988@gmail.com>

> Hi, all,
> I am not sure that I made a mistake or two minor bugs in camlp4 revised
> syntax?
>
> Both cases are in toploop, after I type
>
> #camlp4r;;
> #load "camlp4rf.cma";
> Register.loaded_modules;
> - : ref (list string) =
> {Pervasives.contents=
> ["Camlp4ListComprenhsion"; "Camlp4MacroParser"; "Camlp4MacroParser";
> "Camlp4GrammarParser"; "Camlp4OCamlRevisedParserParser";
> "Camlp4QuotationExpander"; "Camlp4OCamlRevisedParser"]}
>
>
> case1:
> for the signature parsing,
>
> when I type
> value x ~num(num=3) y = num > 0 ;
> --> value x: ~?num:int -> bool
>
> However, the signature can not be parsed by Camlp4
> value parse_sig = Camlp4.PreCast.Syntax.(Gram.parse_string sig_item
> Loc.ghost);
>
> parse_sig "value x : ~?num:int -> bool;" will raie an exception
> however, I tried parse_sig "value x : ?num:int -> bool ;", it's ok,
>
> - : Camlp4.PreCast.Syntax.Ast.sig_item =
> Camlp4.PreCast.Syntax.Ast.SgVal <abstr> "x"
> (Camlp4.PreCast.Syntax.Ast.TyArr <abstr>
> (Camlp4.PreCast.Syntax.Ast.TyOlb <abstr> "num"
> (Camlp4.PreCast.Syntax.Ast.TyId <abstr>
> (Camlp4.PreCast.Syntax.Ast.IdLid <abstr> "int")))
> (Camlp4.PreCast.Syntax.Ast.TyId <abstr>
> (Camlp4.PreCast.Syntax.Ast.IdLid <abstr> "bool")))
> case 2:
> when I type
> module X = struct type a = int and b = (int * int); end;
> in the toploop
> module X : sig type a = int; and b = (int * int); end
> you can see the semi is redudant, it is an error?
>
> I thought Camlp4 was heavily used in bootstrapping itself, did I make
> some stupid assumptions??
>
> Thanks
>
>
>
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa-roc.inria.fr/wws/info/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs
>
>

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[Caml-list] Re: two bugs in camlp4? Help!!

[bobzhang]

Hi, thanks, the first bug is the parser, I mean 
Camlp4.PreCast.Syntax.Gram.sig_item
The second is about printer, right?

I used the two toy examples just to demonstrate my ideas.
Thanks again.

于 11-5-9 下午11:05, Gabriel Scherer 写道:
>     when I type
>     value x ~num(num=3) y = num > 0 ;
>
>     --> value x: ~?num:int -> bool
>
>     However, the signature can not be parsed by Camlp4
>
>     however, I tried parse_sig "value x : ?num:int -> bool ;", it's ok,
>
>
> This seems to be a bug in the printer.
> (By the way, it is not useful to declare an optional argument as last
> parameter of a function, because it cannot be erased. You will have to
> pass it explicitely (otherwise caml couldn't make the difference between
> writing the function and writing the function application, writing (x
> ~num:None) to get the default value).
>
>       module X : sig type a = int; and b = (int * int); end
>     you can see the semi is redudant, it is an error?
>
>
> Again, this looks like a printer issue. The correct syntax has no
> semicolon before "and":  (type .. and .. and ...) is a single phrase.
>
> For a relatively comprehensive documentation of the revised syntax¹, see
> http://caml.inria.fr/pub/docs/tutorial-camlp4/tutorial005.html
> (This is the revised syntax as of camlp4 < 3.10, and possibly Camlp5; in
> current versions of Camlp4 I think the rules have been slightly relaxed,
> but that it is backward-compatible.)
>
> 2011/5/9 bob zhang <bobzhang1988@gmail.com <mailto:bobzhang1988@gmail.com>>
>
>     Hi, all,
>     I am not sure that I made a mistake or two minor bugs in camlp4 revised
>     syntax?
>
>     Both cases are in toploop, after I type
>
>     #camlp4r;;
>     #load "camlp4rf.cma";
>     Register.loaded_modules;
>     - : ref (list string) =
>     {Pervasives.contents=
>     ["Camlp4ListComprenhsion"; "Camlp4MacroParser"; "Camlp4MacroParser";
>     "Camlp4GrammarParser"; "Camlp4OCamlRevisedParserParser";
>     "Camlp4QuotationExpander"; "Camlp4OCamlRevisedParser"]}
>
>
>     case1:
>     for the signature parsing,
>
>     when I type
>     value x ~num(num=3) y = num > 0 ;
>     --> value x: ~?num:int -> bool
>
>     However, the signature can not be parsed by Camlp4
>     value parse_sig = Camlp4.PreCast.Syntax.(Gram.parse_string sig_item
>     Loc.ghost);
>
>     parse_sig "value x : ~?num:int -> bool;" will raie an exception
>     however, I tried parse_sig "value x : ?num:int -> bool ;", it's ok,
>
>     - : Camlp4.PreCast.Syntax.Ast.sig_item =
>     Camlp4.PreCast.Syntax.Ast.SgVal <abstr> "x"
>     (Camlp4.PreCast.Syntax.Ast.TyArr <abstr>
>     (Camlp4.PreCast.Syntax.Ast.TyOlb <abstr> "num"
>     (Camlp4.PreCast.Syntax.Ast.TyId <abstr>
>     (Camlp4.PreCast.Syntax.Ast.IdLid <abstr> "int")))
>     (Camlp4.PreCast.Syntax.Ast.TyId <abstr>
>     (Camlp4.PreCast.Syntax.Ast.IdLid <abstr> "bool")))
>     case 2:
>     when I type
>     module X = struct type a = int and b = (int * int); end;
>     in the toploop
>     module X : sig type a = int; and b = (int * int); end
>     you can see the semi is redudant, it is an error?
>
>     I thought Camlp4 was heavily used in bootstrapping itself, did I make
>     some stupid assumptions??
>
>     Thanks
>
>
>
>
>     --
>     Caml-list mailing list.  Subscription management and archives:
>     https://sympa-roc.inria.fr/wws/info/caml-list
>     Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
>     Bug reports: http://caml.inria.fr/bin/caml-bugs
>
>

Re: [Caml-list] two bugs in camlp4? Help!!

[xclerc]

Le 9 mai 2011 à 16:16, bob zhang a écrit :

> Hi, all,
> I am not sure that I made a mistake or two minor bugs in camlp4 revised
> syntax?
> 
> Both cases are in toploop, after I type
> 
> #camlp4r;;
> #load "camlp4rf.cma";
> Register.loaded_modules;
> - : ref (list string) =
> {Pervasives.contents=
> ["Camlp4ListComprenhsion"; "Camlp4MacroParser"; "Camlp4MacroParser";
> "Camlp4GrammarParser"; "Camlp4OCamlRevisedParserParser";
> "Camlp4QuotationExpander"; "Camlp4OCamlRevisedParser"]}
> 
> 
> case1:
> for the signature parsing,
> 
> when I type
> value x ~num(num=3) y = num > 0 ;
> --> value x: ~?num:int -> bool

Under 3.12.x, "value x ~num(num=3) y = num > 0 ;" cannot be parsed.
It is likely that what you want to write is "value x ?(num = 3) y = num > 0;".

The printed signature is then "value x : ~?num:int -> 'a -> bool" which is bogus.
It should be "value x : ?num:int -> 'a -> bool"; a fix has just been committed for
inclusion in the upcoming 3.12.1.


> case 2:
> when I type
> module X = struct type a = int and b = (int * int); end;
> in the toploop
> module X : sig type a = int; and b = (int * int); end
> you can see the semi is redudant, it is an error?

This is another bug in the toplevel printer for the revised grammar.
Another fix has been committed.


Thanks for reporting,

Xavier Clerc