On Sep 24, 2005, at 12:57 AM, Steven Arnold wrote:

> Hi,
>
> I was reading PickAxe and came across the very cool concept of  
> "once" methods, which are methods that only evaluate when first  
> called, returning a cached value for subsequent calls.

This is usually called memoization, but I'm not aware of a standard  
library that handles it.

James Edward Gray II