[ZPT] Re: [Zope3-dev] attr name space (was: RFC: abolishing python: expressions)

[Fred Drake]

Alexander Limi sent this note to the zope3-dev list:

    http://mail.zope.org/pipermail/zope3-dev/2005-December/017270.html

Essentially, he proposed that we introduce additional namespaces to
allow each define or attribute to be computed in a separate attribute,
something like this:

> <a attr:href="some/url"
>    attr:title="some/title" />

There's been a good bit of discussion, with both proponents and
detractors.  I'll try to summarize fairly; if anyone thinks I've
mis-represented what's been said, please correct me.

Proponents say:

- Using ";" and multiple lines to define variables is hard to read.
- Using ";;" as an escape is difficult to understand.
- Separate attributes are easier to handle for XML tools (no
semicolons with any meaning)
- More consistent syntax, no need to learn a special way to separate
several attributes/defines

Opponents say:

- The more limitted attribute set makes it easier to verify using schemas.
- Order of evaluation could not be well-defined without being arbitrary.
- More namespaces means more to learn.

Continuing discussion should take place on the ZPT list, since this
affects more than just the Zope-based ZPT users.


  -Fred

--
Fred L. Drake, Jr.    <fdrake at gmail.com>
"There is no wealth but life." --John Ruskin