On Wed, Dec 1, 2021 at 7:51 AM Chris Angelico rosuav@gmail.com wrote:
On Wed, Dec 1, 2021 at 10:30 PM André Roberge andre.roberge@gmail.com wrote:
- Independently: Is the syntactic distinction between "=" and "=>" a
cognitive burden?
Yes. I really think that using a keyword like defer, or from_calling_scope
;-), would significantly reduce the cognitive burden.
Also fair. I'm not a fan of keywords for this sort of thing, since it implies that you could do this:
def f(x=defer []): ...
dflt = defer [] def f(x=dflt): ...
which is a completely different proposal (eg it would be evaluated only when you "touch" that, rather than being guaranteed to be evaluated before the first line of the function body). That's why I want to adorn the equals sign and nothing else.
Shouldn't the PEP contain a rejected idea section where this could be mentioned?
- If "no" to question 1, is there some other spelling or other small
change that WOULD mean you would use it? (Some examples in the PEP.)
*Perhaps* if a keyword would be used instead of symbols, I might
reconsider.
I find the emphasis of trying to cram too much information in single
lines of code to be really a burden. Many years ago, I argued very unsuccessfully for using a 'where:' code block for annotations. (To this day, I still believe it would make the code much more readable, at the cost of a slight duplication.) Using what is at first glance a cryptic operator like => for late binding is not helping readability, especially when type annotations are thrown in the mix.
Aside: at the same time, I can see how using => instead of lambda as a
potential win in readability, including for beginners.
It's interesting how different people's views go on that sort of thing. It depends a lot on how much people expect to use something. Features you use a lot want to have short notations, features you seldom use are allowed to have longer words.
I rarely use lambda in my own code, and have never written a line of code
anywhere that uses a '=>' operator.
If Python had a 'function' keyword instead of 'lambda', I would prefer to keep the function keyword instead of adding => as a symbol. For me, it is not a question of terseness for commonly used features, but one of easing the learning curve. Starting from zero, I do believe that => would be easier to grasp than learning about lambda as a keyword and the syntactic rules to use with it. With function as a keyword, I believe that it is the other way around. No doubt many others will disagree!
André Roberge
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