Pattern matching accepted for Python

Re:Pattern matching accepted for Python by carapace on Wednesday February 10, 2021 @09:05PM (#26097395)

The underlying mechanism doesn't work the same though, e.g. in C assigning to a variable "mutates" the contents of RAM, in Python it mutates the namespace dictionary (which of course also results in some RAM contents changing too, but through a relatively elaborate abstraction.)

> Shouldn't terms like this be cross-language?

Variables in C are different beasties than variables in Python, and variables in Prolog are different from both, and none of those are like variables in math. It's a source of confusion that we use the word "variable" for a host of similar concepts. The word "type" is similarly overloaded in CS. (See https://www.cs.kent.ac.uk/people/staff/srk21/research/papers... )

FWIW, I'm just explaining what wendyshu was on about above. :)

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Re:Pattern matching accepted for Python by Dylan16807 on Thursday February 11, 2021 @01:10AM (#26098754)

That's not exactly how C works, but I wasn't going to use C as my primary example, I was going to use Rust. You have to write "let mut" to let a variable be reassigned/mutated, and variables in Rust are almost identical to ones in Python as far as being an abstract 'namespace' binding.

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Re:Pattern matching accepted for Python by carapace on Thursday February 11, 2021 @10:18AM (#26102337)

> That's not exactly how C works

Sure, I elided a bajillion details, and who knows what the CPU is doing under the hood anyway? :)

I've never used rust (yet) so I can't really comment on that.

FWIW namespaces in Python aren't abstract, they exist as dicts at runtime. You can modify the dict you get back from locals() or globals() and change your "variables" in scope:

    >>> d = locals()
    >>> d['cats'] = 'meow'
    >>> cats
    'meow'

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