[Zope3-dev] ? vs $

[Jim Fulton]

"Barry A. Warsaw" wrote:
> 
...

> If you're worried about colliding with identifiers that start with $,
> write
> 
>     <span tal:replace="context/${jobid}/summary">...
> 
> Probably a low likelihood of collisions (and if so, use $$ to
> disambiguate).  I think it's more important to make similar operations
> look similar so it's clear at first glance what the intention is.

This reminds me of another reason that '?' was used.

We really didn't want to allow arbitrary string substitution because the
semantics get a but squishy.

  foo/?bar

means traverser foo with the name contained in bar, no matter what
characters were in the name.

Suppose the value of bar is "baz/splat". I might
expect:

  foo/$bar 

to be equivalent to:

  foo/baz/splat

but part of the value of foo/?bar is that it 
allows you to use '/' in a name.

Consistent use of syntax is a bad thing when the semantics are different.


Jim

--
Jim Fulton           mailto:jim@zope.com       Python Powered!        
CTO                  (888) 344-4332            http://www.python.org  
Zope Corporation     http://www.zope.com       http://www.zope.org