Suggestion: make sequence and map interfaces more similar

[Steven D'Aprano]

On Wed, 30 Mar 2016 11:50 pm, Random832 wrote:

> Absolutely nothing is stable under a *completely unrestricted* set of
> operations.

Yes, you're absolutely correct. If I create a Python dict, {1: 'a'}, and
then smash the computer to smithereens with a 50lb sledge hammer, neither
the key nor the value will still be accessible. Well done. I never would
have thought of that violation of the dict invariants without you.


>> Specifically, insertions and deletions to the mapping never affect the
>> existing keys.
> 
> You can't say that, because there is no insert and delete method in the
> mapping interface.

There are in the dict API though.

# insertions
d[key] = value

# deletions
del d[key]



>> If somebody wants to insist that this is a kind of mapping, I can't
>> disagree, but it isn't useful as a mapping type.
> 
> Javascript seems to manage it just fine.

I wouldn't exactly hold Javascript up as the exemplar of intelligent design
decisions.


-- 
Steven