From: Matthieu Riou <matthieu.riou@...>
Date: 2007-02-20T13:27:33+09:00
Subject: Re: [YAML] To quote or not to quote (I think it's a bug)

------=_Part_35406_3474792.1171945646635
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

Hi Tim,

In that page:

"Any "*_*" characters in the number are ignored, allowing a readable
representation of large values."

So clearly they're allowed, in 1.2_3 the underscore is simply ignored and
the parser should undestand 1.23. If I fancy to write my own YAML by hand
and make it easily readable (which is kind of the original purpose) I could
write 100_000_000.03 which would be a nice looking float. Hence the
ambiguity with "1.2_3".

Cheers,
Matthieu

On 2/19/07, Tim Pease <tim.pease@gmail.com> wrote:
>
> On 2/19/07, Matthieu Riou <matthieu.riou@gmail.com> wrote:
> > Hi,
> >
> > I'm not sure this is the right place to report issues about Syck but
> that's
> > the best I've found so far :) I think I've found a problem with the way
> Syck
> > quotes strings that could look like floats. Here is a short example:
> >
> > irb(main):001:0> require 'yaml'
> > => true
> > irb(main):002:0> YAML.dump(["1.2", "1.2.3", "1.2_3"])
> > => "--- \n- \"1.2\"\n- 1.2.3\n- 1.2_3\n"
> >
> > The first element is quoted appropriately, the second isn't because
> there's
> > no ambiguity but the third should be quoted. The YAML float can have
> > underscores, they're used as visual separators and should be ignored by
> the
> > parser. So when seeing 1.2_3 the parser should read the float 1.23. Then
> to
> > disambiguates the string "1.2_3" should be quoted.
> >
> > Practically this isn't really a problem as YAML converts on writes so
> > YAML.dump(1.2_3) gets directly written as 1.23. However it creates some
> > interoperability issues when "1.2_3" gest written unquoted by Syck and
> then
> > read by another parser as being 1.23. The string isn't a string anymore
> in
> > that case.
> >
>
> Are you certain that 1.2_3 is a valid YAML float?
>
> http://yaml.org/type/float.html
>
> I do not believe underscores are valid in either YAML floats or YAML
> integers. Although they are allowed in Ruby, I believe Syck is
> handling your example case properly and without ambiguity.
>
> Blessings,
> TwP
>
>

------=_Part_35406_3474792.1171945646635--