Even if f{1} creates a frozenset, I don't think f{} should create a frozenset. I think it makes more sense to keep f{1: 2} open for frozendict if it ever makes it in. Also, {} should be consisten with f{} (both should create dicts). If you want an empty frozenset, you would have to do it the same way you do it for sets: either frozenset() or f{*()}. Best Neil On Tuesday, January 18, 2022 at 1:19:30 PM UTC-5 João Bernardo wrote:
One thing to consider is if we're going to have a syntax capable of creating an empty frozenset, we need one that creates an empty set.
if f{...} exists, then s{...} should also exist?
Regards João Bernardo
On Tue, Jan 18, 2022 at 2:59 PM Rob Cliffe via Python-ideas < python...@python.org> wrote:
I'm +1 on the idea. I'm happy with the f{ ... } syntax (although I did suggest something else). We already have letter-prefixes, let's stick to them rather than adding something new (which conceivably might one day find another use). Best wishes Rob Cliffe
On 18/01/2022 15:53, Ricky Teachey wrote:
On Tue, Jan 18, 2022 at 10:02 AM Joao S. O. Bueno <jsb...@python.org.br> wrote:
but I don't think we should underestimate the cost of even this small complexity increase in the language.
Actually, I think _maybe_ in this case the "complexity increase" cost is _negative_. People might waste more time looking for a way of spelling a frozenset literal than just filling in "frozenset(....)". I for one, even knowing that the cost of writing "frozenset({1,2,3})" is negligible, would "feel" better there was a way to spell that without the needless conversions.
That said, an appropriate prefix for the {} just as we do for strigns would be nice, and I disagree that it would be a significant source for "bugs". The "@{" is a nice way out if people think "f{}" would be too close to "f()". And "<1,2,3>" just for frozensets are indeed overkill. We already do "literal prefixing" with `"` after all. and formally extending this prefix usage as needed for other literals seems like a nice path. But, as far as bikeshedding go, we also have "literal sufixing" (2.0j anyone?)- maybe "{1,2,3}f" ?
I have been following along with not much to comment but this response sparked something in me.
After reading all the viewpoints I think I would be +1 on the basic idea, and a +1 on the postfix/suffix syntax just suggested... the other syntaxes I'm more of +0.5
I like the way the suffix FLOWS with the act of writing the program. When I write a set, I am primarily focused on *what I am going to put in it*, and whether or not it should be mutable is kind of a later thought/debate in my head after I have established what it contains.
As a dumb example, if my task at hand is "I need to create a bag of sports balls", I am mostly thinking about what goes into that bag at first, so I will write that first:
{Ball("basketball"), Ball("soccer"), Ball("football"), Ball("golf")}
Now I get to the end of that line, and I then sort of naturally think "ok does it make sense to freeze this" after i know what is in it. With the postfix syntax, I then either type the f:
{Ball("basketball"), Ball("soccer"), Ball("football"), Ball("golf")}f
...or not. With a prefix type syntax, or a smooth bracket syntax, either:
A. it takes slightly more "work' at this point to "convert" the set to a frozenset, OR B. i have to think about ahead of time-- before i have actually written what is in the set- whether it will be frozen, or not.
In contrast, when you are deciding whether to write a list vs a tuple, you are deciding between two things that are fundamentally far more different IDEAS than a "bag of things, frozen or unfrozen". A list is very often more of an open ended stack than it is "an unfrozen tuple". A tuple is very often much more of an object that can be used as a dictionary key, or a member of a set, than it is a container of things (of course, it is a container of things, too). These differences make is a lot easier to choose, ahead of time, which one makes sense before you have even written the line of code.
Maybe I'm making too much of this, but I really like the idea of deciding at the END of the set literal whether to tack on that "f".
--- Ricky.
"I've never met a Kentucky man who wasn't either thinking about going home or actually going home." - Happy Chandler
_______________________________________________ Python-ideas mailing list -- python...@python.org To unsubscribe send an email to python-id...@python.orghttps://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python...@python.org/message/T7X3XI3ZQ... <https://mail.python.org/archives/list/python-ideas@python.org/message/T7X3XI...> Code of Conduct: http://python.org/psf/codeofconduct/
_______________________________________________ Python-ideas mailing list -- python...@python.org To unsubscribe send an email to python-id...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/
Message archived at
https://mail.python.org/archives/list/python...@python.org/message/VRGSQR7IS... <https://mail.python.org/archives/list/python-ideas@python.org/message/VRGSQR...>
Code of Conduct: http://python.org/psf/codeofconduct/