Re: [Yaml-core] "syntax only" model, type agnosticism

[Brian I. <in...@tt...>]

On 07/09/02 09:52 +0200, Rolf Veen wrote:
> Clark C . Evans wrote:
> 
> > What do you think about requiring parenthesis around all items
> > which are implicitly typed?
> > 
> > strings:
> >  - 23
> >  - 2002-01-02
> >  - true
> >  - 2.3
> > typed:
> >   integer: (23)
> >   timestamp: (2002-01-02)
> >   boolean: (true)
> >   floating: (2.3)
> > 
> 
> 
> I'll repeat myself:
> 
> strings:
>   - 23
>   - 2002-01-02
>   - true
>   - 2.3
> typed:
>    integer: ! 23
>    timestamp: ! 2002-01-02
>    boolean: ! true
>    floating: ! 2.3
> typed:
>    integer: !int 23
>    timestamp: !time 2002-01-02
>    boolean: !bool true
>    floating: !float 2.3

+1 on the above

parens:
   integer: (23)
   timestamp: (2002-01-02)
   boolean: (true)
   floating: (2.3)

This syntax is a little nicer looking than '! foo'. I could go either
way, but I'd prefer both ways.

> 
> and my vote for this proposal :-):
> 
> +1
> 
> The single transfer indicator turns implicit type detection
> on. This is compatible with an #IMPLICIT directive, also.
> The #IMPLICIT directive defines the default. No directive means
> OFF.

Just turning implicit typing on/off is a good start. But Clark's breakthrough
of specifying *which* implicits, and my breakthrough of grouping them into
classes, is much more powerful. It allows a user to select their
implicits for various domains. It allows us to come up with many more
implicit patterns than we were comfortable with before. Currency anyone? Most
importantly it allows user domains to define their own implicits.

The key was to get explicit about being implicit. And when you're completely
implicit you get strings, which seems to cause the least trouble by far.

> 
> Also -1 for using '-' as an implicit boolean. It complicates
> the productions. Grammar complexity surfaces up to the user
> level, which has to remember too many rules when writing or
> reading a YAML file.

+1 

But that's a fight for a different day :)

Cheers, Brian