[Zope-dev] 'not:' kludgey?!

[Marc Lindahl]

on 5/13/02 3:11 PM, Chris Withers at chrisw@nipltd.com scrivened:

>> 
>> For the reasons 'else' was invented in the first place,
> 
> 'else' in what context?!

Meaning, in procedural languages.

> 
>>  I guess:  prone to
>> errors, inefficient, bulky.
> 
> Can you give any material that actually backs up these sweeping claims? ;-)

Prone to errors: when changing the condition, have to duplicated edits in 2
places, so you could make an error which would be hard to track down.
Inefficient: have to evaluate an expression twice (unless someone makes a
jit compiler!)
Bulky: in terms of taking more space in the source file, without clarifying
what's being done.

> 
>> The biggest thing I see is: isn't linked to the
>> other construct, so it's prone to errors when editing the conditions.
> 
> Well, I've already shown the way I'd do this which only has the condition in
> one
> place....

Yes you did, and re-reading the TAL wiki
(http://www.zope.org//Wikis/DevSite/Projects/ZPT/TAL%20Specification%201.2)
it's clear that your approach is the one the language is designed for.
Also, your approach can easily accommodate other logic structures like case
statement.  Well, I guess I'm convinced!