[Caml-list] Ocaml parser reports strange syntax-error position.

[Caml-list] Ocaml parser reports strange syntax-error position.

[Matej Kosik]

Hi,

If I type this to the Ocaml toplevel:

  Printf "%d" 10;;

The actual problem is that instead of "Printf" I should have typed "Printf.printf".

However, the parser complains about literal "10".

Is this the expected behavior or a bug (in parser's error-reporting routines)?

Re: [Caml-list] Ocaml parser reports strange syntax-error position.

[Romain Bardou]

Le 05/06/2013 11:49, Matej Kosik a écrit :
> Hi,
> 
> If I type this to the Ocaml toplevel:
> 
>   Printf "%d" 10;;
> 
> The actual problem is that instead of "Printf" I should have typed "Printf.printf".
> 
> However, the parser complains about literal "10".
> 
> Is this the expected behavior or a bug (in parser's error-reporting routines)?
> 

I guess it believes Printf here is not a module name (there is no dot)
but a constructor (it is a capitalized identifier). But the syntax for
constructors is either:
  A
  A x
  A (x1, ..., xn)
In other words, if A is a constructor, "A x y" is never a valid
expression. It could also be a type error ("A x" is not a function, it
cannot be applied) but apparently it is catched by the parser.

So I would say it is the expected behavior, but that it could be
improved, as all error messages.

-- 
Romain Bardou

Re: [Caml-list] Ocaml parser reports strange syntax-error position.

[Goswin von Brederlow]

On Wed, Jun 05, 2013 at 11:52:49AM +0200, Romain Bardou wrote:
> Le 05/06/2013 11:49, Matej Kosik a écrit :
> > Hi,
> > 
> > If I type this to the Ocaml toplevel:
> > 
> >   Printf "%d" 10;;
> > 
> > The actual problem is that instead of "Printf" I should have typed "Printf.printf".
> > 
> > However, the parser complains about literal "10".
> > 
> > Is this the expected behavior or a bug (in parser's error-reporting routines)?
> > 
> 
> I guess it believes Printf here is not a module name (there is no dot)
> but a constructor (it is a capitalized identifier). But the syntax for
> constructors is either:
>   A
>   A x
>   A (x1, ..., xn)
> In other words, if A is a constructor, "A x y" is never a valid
> expression. It could also be a type error ("A x" is not a function, it
> cannot be applied) but apparently it is catched by the parser.
> 
> So I would say it is the expected behavior, but that it could be
> improved, as all error messages.

Can't be a function since it start with an uppercase.

Otherwise you are spot on:

# Printf "%d";;
Error: Unbound constructor Printf

MfG
	Goswin