Re: Implicit Typing

On Wed, 2007-05-02 at 01:09 -0700, Ingy dot Net wrote:
> > The boolean case raises a second issue however. There is a conflict
> > between "correctly" guessing the types of data with utter lack of schema
> > information, and "correctly" interpreting the value of data when the
> > schema is known. In the boolean case, this means that when reading a
> > random-off-the-street file without any knowledge what it means,
> > interpreting Y as a string seems to be the right thing to do. At the
> > same time, when a server application is reading reading a boolean field
> > in its own dedicated configuration file, interpreting the same Y
> > character as the boolean value true also seems as the right thing to do.
> > 
> > This leaves us in something of a bind. The immediate solution that comes
> > to mind is:
> 
> Why does this leave us in a bind? 
>
> I would say that your server application would be aware that its
> configuration file had implicit booleans, and would then set the appropriate
> option in the YAML Loader module/object/whatever to DTRT.

So far, so good. The problem is that, say, a YAML-pretty printer would
feel justified in stripping away quotes around a "Y", not knowing that
the server application will then start treating it as a boolean (assume
a polymorphic field for a second).

The challenge is to define rules that allow the specific application to
do what it wants to without a fuss, while keeping the generic programs
safe. The spec addresses this for the most part; the missing piece is
defining the "basic set of types".

How do you feel about defining such a basic set and requiring an
explicit tag if venturing outside it?

> One more thing... could you stop referring to the "Parser" when talking bout
> typing. IMO, no typing activity happens at the parser level. Use the term
> Composer or at least Loader.

My bad, you are absolutely correct. The name of the relevant processing
phase is "compose" so I suppose I should have said "composer" :-)

Have fun,

	Oren Ben-Kiki


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