[Newbies] constants

Mark Volkmann mark at ociweb.com
Mon Sep 29 10:53:11 UTC 2008


On Sep 28, 2008, at 11:32 PM, K. K. Subramaniam wrote:

> On Sunday 28 Sep 2008 7:26:43 pm Mark Volkmann wrote:
>> I think my main issue is scoping. I want to define a constant that is
>> associated with a class to avoid name conflicts.
> See classes Color, Cursor or Float for examples of scoped constants:
>   Color red
>   Cursor wait
>   Float pi
>
> For constants that should be exposed to a few (but not all) classes,  
> use pool
> dictionaries.

Thanks! This brings up another question. Where is a good place to  
initialize a constant? I see in the case of "Float pi" that it is held  
in a class variable that is initialized in the initialize method.  
Isn't it the case that the initialize method is only called if a Float  
object is created? Also, isn't it called every time a Float object is  
created? It seems that would mean if I followed that pattern for one  
of my own constants then I wouldn't be sure it was set and I'd pay the  
cost of setting it many times.

---
Mark Volkmann






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