[Python-ideas] Make keywords KEYwords only in places they would have syntactical meaning
steve at pearwood.info
Fri May 18 07:59:46 EDT 2018
On Fri, May 18, 2018 at 07:22:13PM +0800, Ken Hilton wrote:
> Only treat keywords as having any special meaning when they are in places
> with syntactical significance.
> My idea is to only treat keywords as having special meaning when they're in
> the right place.
Chris discussed his experience with REXX, which works like that:
The problem is that you can go a long way down the road of
using a particular name, only to find that suddenly you can't
use it in some particular context. [...]
So the question is: Is it better to be able to use a keyword
as an identifier for a while, and then run into trouble later,
or would you prefer to be told straight away "no, sorry, pick
a different name"?
I think its a no-brainer: I'd much rather get an error earlier, when I
first decide its a good idea to call a method "while", rather than six
months later when I stumble across a corner case that stops me from
I'm sure that everyone is absolutely champing at the bit to write code
for = if if while else else
or = [in or for for in in for if if]
*wink* but I think we should be conservative about allowing keywords as
identifiers. Requiring a clear and obvious escaping mechanism (verbatim
strings \name) or a clear and obvious renaming convension (name_) is
better than a context-sensitive grammar.
That's even assuming such a context-sensitive grammar would be possible
within the requirement that Python's parser is LL(1).
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