[ZPT] Possible changes to path-related

[R. David Murray]

On Tue, 1 May 2001, Evan Simpson wrote:
> The only thing I've been able to think of, and I don't really like it,
> is to get wordy:
> 
> (use-if-exists)
> (use-if-true)

(use-if-exists-and-true) ?

I actually kind of like these <wry grin>.  They seem more expressive of
what's going on.

> I think about these modifier using an analogy to Python.  I translate as
> follows (ZPT spelling on the first line, then Python spelling):
> 
> tal:action="path:foo"
> action(foo)
> 
> tal:action="path:(if) foo"
> if foo:
>     action(foo)
> 
> tal:action="path:(exists) foo"
> action(exists('foo'))

So 'action' knows not to do anything if exists returns "some special flag",
right?

> tal:action="path:(if exists) foo"
> if exists('foo'):
>     action(foo)

Now here is exactly where I think the confusion lies, and if I'm
right this makes a pretty dramatic statement of how confusing it is,
if the inventor got it wrong <grin>.  Shouldn't this read:

if exists('foo') and foo:
	action(foo)

--RDM