[omega] Re: Antonio

[gabor.bella at enst-bretagne.fr]

Quoting Antonio Regidor García <a_regidor at yahoo.es>:

>
> --- Yannis Haralambous <yannis.haralambous at enst-bretagne.fr> wrote:
>
> > don't forget that OTPs and fonts act on characters or on glyphs (or
> > on properties). It is easier to act on something simple
> > so that we can write patterns and regular expressions. I think that
> > we should start experimenting with only simple
> > properties (name = single value), and switch to complex properties
> > only if we find it absolutely necessary.
>
> I see the convenience of having a simple and at some extent standard
> key to index and manage textemes (I like the term too). Anyway, if the
> character is simple, I don't see too much problems on allowing property
> values that are pointers to complex structures.

Pointers only work if the underlying memory structure is shared among all
steps of the text layout process. This is true if layout is done by a
single programme such as TeX but not if the texteme string is passed to
completely separate processes like external OTP's. IMHO, one of the main
advantage of textemes is that they are (most of the time) stand-alone,
self-containing entities, as opposed to the separate
character/glyph/property string model used by other layout systems.

Having said that, I still think that attaching more complex structures to
properties is something we will definitely need sooner or later. But this
complexity, as Yannis said, should not interfere with plain regex-based
OTP's that only act on simple properties.

> I was only worried about the possibility that allways supposing that a
> property is simple will hard-code this limitation in Omega, and
> subsecuent extensions will became very difficult.

We agree on this.

Lastly let me add that I'm thrilled to be able to discuss questions such as
these on this mailing list. Besides working on Omega, I'm doing my thesis
precisely on this subject so your input and ideas are helpful in two ways
at the same time. :-)

Regards,
Gábor