Suggestion: make sequence and map interfaces more similar

[Marco S.]

Steven D'Aprano wrote:

> The point you might have missed is that treating lists as if they were
> mappings violates at least one critical property of mappings: that the
> relationship between keys and values are stable.


This is true for immutable maps, but for mutable ones, you can simply do

map[key] = new_value

You can easily create a new class that extend dict and add to it a
method that emulated the insert method of lists. It will definitively
not break any contract, if your contract is "sequences are maps with
ordered integer keys that starts from zero and have no gaps".

Mark Lawrence wrote:

> I cannot see this happening unless you provide a patch on the bug
> tracker.  However I suspect you can get the same thing by subclassing
> dict.  Why don't you try it and let us know how you get on?

The problem with a vdict is that I should also create by zero a new
interface (ABC), since MutableMapping have an incompatible contract.
And to be much more useful I should code it inc C, and my C skills are
not so magnificent. Furthermore I would try to create a new sequence
interface that inherit from the vdict interface. More briefly, I need
much free time. But I suppose I can start with something quick and
dirty.