Re: List container strawman 1.2

[Ted Dennison<dennison@telepath.com>]

In article <3BF3EDE5.FE0ED701@brighton.ac.uk>, John English says...
(good stuff all)
>
>Iterator is nice too but instantiating the generic (and wrapping the
>operation in an approapriately-shaped procedure first) is probably
>more hassle than a while I <> Last(L) loop, IMHO...

That's my feelings on it too. Additionally, I've found you have to use globals
in the routine to get all of your real work done, which rubs the wrong way
against about 13 years of training on my part. But there are those here who
swear by passive iterators.

>another one I might one would be Shuffle, which is about the same
>level of difficulty... maybe a generalisation such as Swap(Index,Index)
>might be a useful building block for algorithms of this sort.

I suppose. That would let someone write themselves a Bogo-sort if they really
want to.

>I also think that an Index needs to know which list it refers to,
..

We've been down that road. The place it leads is that if you want safe
iterators, you have to make both the indices and the lists controlled and keep a
little mini-list of iterators in each list. The algorithms for doing this
properly aren't unachieveable, but they do make everything quite a bit more
complex. They also create a situation where real-time users will have to be a
lot more careful when they iterate through a list to aviod heap operations.

The current version takes the opposite stance. I'm wavering quite a bit in my
support for it though.

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