[Python-Dev] from tuples to immutable dicts (original) (raw)

Armin Rigo arigo@tunes.org
Fri, 29 Nov 2002 03:50:43 -0800 (PST)

Hello Martin,

On Sun, Nov 24, 2002 at 06:10:54PM +0100, Martin v. Loewis wrote:

> point = tuple(5, 6, color=RED, visible=False)

I have to problems imagining such an extension: 1. I'm not sure this would be useful. 2. I can't imagine how to implement it, without compromising performance for tuples.

By introducing a subtype of tuple, just as you do in Python. By the way, doing it in Python is a nice thing, but then we end up with two ways of making this kind of small structures: one easily available in Python but not in C, and one (structseq) for C. Having a C-based implementation of tuple-with-immutable-dict would unify the two. But well, I realize that I'm getting stuck with minor things here.

An example that comes in mind where a C-based immutable dict would be handy is to implement table-based jumps in the bytecode (for switches), but again this discussion drifted in incompatible directions as we need non-string keys for this.

Let's just forget it all.

Armin