If `def(if=3)...` works implicitly, then why not make `if = 3`, `x.if = 3`, `import if`, `def if` and `class if` implicit too?
Another issue is what happens here: keyword if import if f(if=3) f.if = 3 The keyword will be a valid name in old code, so you need to be able to reference it as a name in code that uses it as a keyword. -- Carl Smith carl.in...@gmail.com On 16 May 2018 at 18:24, Adam Bartoš <dre...@gmail.com> wrote: > Hello, > > I have yet another idea regarding the the clashes between new keywords and > already used names. How about introducing two new keywords *wink* that > would serve as lexical keyword/nonkeyword declarations, similarly to > nonlocal and global declarations? > > def f(): > nonkeyword if > if = 2 # we use 'if' as an identifier > def g(): > keyword if > if x > 0: pass # now 'if' again introduces a conditional statement > > This allows to have a name as both identifier and keyword in a single > module, and since it's lexical, it could be in principle syntax-highlighted > correctly. > > When a new keyword is added to the list of standard keywords like 'given' > or 'where', a module that uses the name as identifier could be easily fixed > by a global declaration 'nonkeyword given'. Maybe even exception messages > pointing to this could be added. If 'nonkeyword keyword' is allowed, we can > also fix code using the name 'keyword' as an identifier, but doing so in > the global scope couldn't be undone. > > On the other hand, new language features depending on new keywords could > be made provisionary by not adding the keywords to the standard list, so > people who would like to use them would need to opt in by e.g. 'keyword > given'. Surely, this provisional mechanism isn't robust at all since new > features may just extend the usage of current keywords. > > Declaring a keyword that has no meaning in the language would result in an > exception: > > keyword foo # SyntaxError: undefined keyword 'foo' > > It should be possible to use a keyword as a parameter name without need to > declare it in the surrounding scope, the local declaration would suffice: > > # nonkeyword if # not needed > def f(if=3): # ok > nonkeyword if > > Other option is to interpret parameters always as nonkeywords or to raise > a special syntax error when a keyword occurs at a place of a formal > parameter (similarly to 'def f(x): nonlocal x'). > > Clearly, even if this proposal diminished the cost of adding new keywords, > the cost would still be high. > > > Best regards, > Adam Bartoš > > > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/ > >
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