Re: [Jython-dev] Implementing PyList with java.util.ArrayList

[Michael H. <hag...@jp...>]

Frank Wierzbicki wrote:
> I'm working on implementing some Python 2.3 list behaviors in PyList
> and I've come to deleting a slice with a step value greater than one. 
> Thinking about the problem, it will be a little annoying to do this by
> creating a new array and copying the diffed array in (this is
> essentially how the slice deleting works now).  It occurred to me that
> this would be *much* easier to implement if PyList was backed by an
> ArrayList (just remove() the elements).  In fact much of PyList would
> become simpler, at least with respect to readability and
> maintainability.  Does anyone have any objections to replacing the
> internal array in PyList with an ArrayList, especially given that we
> are dropping Java 1.1 support?

I don't have anything against backing PyList with ArrayList, but you 
should definitely not use remove() to delete a slice. ArrayList would 
have to make a copy for every deleted element, making it an order n*m 
operation (n = length of array, m = length of slice) instead of linear 
in n, as is the copying version.

Michael

-- 
Michael Haggerty
JPK Instruments
hag...@jp...