On Tue, May 15, 2018, 23:03 Carl Smith <carl.in...@gmail.com> wrote: > > >> On Tue, May 15, 2018 at 8:41 PM, Steven D'Aprano <st...@pearwood.info> >> wrote: >> >>> Inspired by Alex Brault's post: >>> >>> https://mail.python.org/pipermail/python-ideas/2018-May/050750.html >>> >>> I'd like to suggest we copy C#'s idea of verbatim identifiers, but using >>> a backslash rather than @ sign: >>> >>> \name >>> >>> would allow "name" to be used as an identifier, even if it clashes with >>> a keyword. >> >> > I strongly disagree, but can't seem to get anyone > to bite. > > We want to be able to introduce a keyword that was formally a name, still > allow > it to be used as a name, still allow code that uses it as a keyword to > interoperate > > with code that uses it as a name > , without changing the language > or implementation > too much. > > Ideally, Python would still not allow the keyword to be used as a name > and a > keyword in the same file?? > > The lexer could class the tokens as *keynames*, and the parser could use > the > context of the first instance of each keyname to determine if it's a name > or > keyword for the rest of that file. Projects that used the word as a name > would > only be prevented from also using it as a keyword in the same file. > > It's really then a question of whether users could elegantly and naturally > reference a name in another module without introducing the name to the > current module's namespace. > > We only reference external names (as syntactic names) in import statements, > as properties after the dot operator, and as keyword arguments. > > If code that used the word as a keyword was still allowed to use the word > as > a name after the dot operator and as a keyword argument *in an invocation*, > it would only change the language in a subtle way. > > If we could reference keynames in import statements, but not import the > name, > so basically allow `from keyname import keyname as name`, but not allow > `import keyname`, we could still easily import things that used the keyname > as a name. This wouldn't change the language too dramatically either. > > Maybe I'm just being dumb, but it seems like three subtle changes to the > language would allow for everything we want to have, with only minor > limitations > on the rare occasion that you want to use the new keyword with a library > that is > also using the same keyword as a name. > > I promise not to push this idea again, but would really appreciate someone > taking > a couple of minutes to explain why it's not worth responding to. I'm not > offended, > but would like to know what I'm doing wrong. > > Thanks. >
I think your idea would work okay if everyone followed good programming practices. But when you have files that are tens of thousands of ugly code written by dozens of non-programmers over a dozen years it sounds like a recipe for a nightmare. For example someone you never met that left your group ten years ago could have made "True" be "np.bool_(1)" on a whim that makes your code break later in very hard-to-debug ways. To put it simply, I think it encourages people to take convenient shortcuts with implications they don't understand. >
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