Re: : in the flow context for PyYAML and SnakeYAML

On 08/25/2010 04:03 AM, Andrey Somov wrote:
> I still do not understand why we do not follow the spec:
>
> 1) {a:1} ->  {"a:1": null} (yes, it is not intuitive, but according to the spec)
> 2) {url: http://dot.com} ->  "url": "http://dot.com"
>
> I think it is better to implement p.1 instead of the current failure
> because we can give a chance to a user to fix the problem at runtime.
>
>
>> I strongly disagreed with it because it does not follow Python or Javascript conventions,
>> but I didn't want to decide one way or another until some consensus is reached.
>> So I made ':' (colon followed by a non-whitespace character) an error when it is a part of a plain literal in the flow context.
>
> People agree on the specification exactly to avoid personal flavors.

I just treated these issues as bugs in the spec.

> For instance I totally disagree to have 18 (!!!) possible alternatives
> for a boolean value but nevertheless I had to implement them all.
> SnakeYAML does not fail on 'Yes'. (even though I am sure it should be
> just !!str)

Yet you may notice that YAML 1.2 spec reduced them to:
  true | True | TRUE | false | False | FALSE

And now we have a problem with compatibility: how could we move to 1.2 
without breaking user's YAML data.  Had we followed the common sense in 
this case, it would be much better for everyone.


> Since 1.2 specification did not make any change about a colon on the
> flow context I feel it is better to follow the spec. I think that this
> is the indication that the consensus is reached.

You are wrong about the 1.2 spec not changing interpretation of a colon 
in the flow context; it is now much closer to what PyYAML does, and 
exactly for the same reasons: compatibility.

In 1.1: {"a":"b"} -> error
In 1.2 (and PyYAML): {"a":"b"} -> {"a": "b"}


Thanks,
Kirill

------------------------------------------------------------------------------
Sell apps to millions through the Intel(R) Atom(Tm) Developer Program
Be part of this innovative community and reach millions of netbook users 
worldwide. Take advantage of special opportunities to increase revenue and 
speed time-to-market. Join now, and jumpstart your future.
http://p.sf.net/sfu/intel-atom-d2d