Lists implemented as integer-hashed Dictionaries?

[Stephen Hansen]

On Fri, Feb 6, 2009 at 7:32 PM, er <erobererunc at gmail.com> wrote:
> Thanks Chris.  Lua tables are one of my favorite linguistic traits, which
> was actually part of the discussion that brought up this nugget.
> Nevertheless, any details you care to provide about the details.  I'm going
> to dive into the source code in more depth tomorrow, just so I can get a
> better understanding anyway, but I'd love to hear some details, or see any
> links, if you have them.

Yeah, as Chris said, Python lists are not dictionaries at all. They're
PyObjects that contain an array of pointers to other PyObjects. Basic
Python types try to be efficient and reliable. They're not always the
perfect choice, but they strive to be good enough for most situations
in terms of both functionality and speed... and while they have put a
lot of effort into tuning Python's hash implementation, an array has
to beat it hands down when you're implementing an ordered sequence.

Now, I believe Python sets *are* for all intents and purposes
dictionaries, but I think that's just because its the easiest and most
efficient way to implement their uniqueness properties; they took the
very-well-tuned dictionary implementation and cut out the stuff not
needed by sets and did some tweaks here or there. I /believe/.

--S