[... big snip...]
On 22Jan2022 01:41, Chris Angelico <[email protected]> wrote:
>On Sat, 22 Jan 2022 at 00:56, Joao S. O. Bueno <[email protected]> wrote:
>> At that point, I argue that despite adding still more things to
>> the syntax, it is one that will spare time in average than the other
>> way around, due to the time people, needing frozensets for
>> the first time in any project, waste looking for a literal syntax for them
>> only to find out there is not any.
>
>Have you any stats on this? There is no literal/display syntax for
>datetimes, regular expressions, ranges, bytearrays, or a host of other
>common types. How often do people reach for a literal syntax for
>those? (I say "literal/display" since, technically, dicts have a
>display syntax, not a literal, and complex numbers are written as a
>constant-folded sum, but in practical terms, those count. The other
>types don't even get that.) If frozensets are so special that they
>need syntax, why not ranges, which are used far more frequently?
Well, some data.
a) if the, for example, f{constant-set-display} syntax is generalisable
(notionally, where we generalise it or not), it offers a path to frozen
literals for other things via a prefix notation, should be become
desirable.
b) literal regexps: people use these _all the time_, conceptually.
To the latter: Perl has literal regexps, you just write:
/regexp-goes-here/
It even has a verbose commentable form of that to aid writing
understandable regexps (hahaha!).
What, we're not Perl? True, but you see _lots_ of code like this:
# apologies if I have the argument order wrong here
if re.match('regexp-string', 'target-string'):
which effectively relies on the re module's autocaching of regexps to be
efficient while skipping the more overt:
# top of module
foo_re = re.compile('regexp-string'[,options])
....
# in the main code
if m := foo_re.match('target-string'):
The former is nothing else but a metaphor for a literal regexp.
I'm _not_ arguing for regexp literals in Python - IMO they're
undesirable, a separate argument. (Note: not "undesired", just
undesirable: to be avoided except when they're the right solution.)
Cheers,
Cameron Simpson <[email protected]>
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