[Python-ideas] Smart/Curly Quote Marks and cPython

[Nick Coghlan]

On 22 October 2016 at 17:36, Ryan Birmingham <rainventions at gmail.com> wrote:
> Per the comments in this thread, I believe that a better error message for
> this case would be a reasonable way to fix the use case around this issue.
> It can be difficult to notice that your quotes are curved if you don't know
> that's what you're looking for.

Looking for particular Unicode confusables when post-processing
SyntaxErrors seems like a reasonable idea to me - that's how we ended
up implementing the heuristic that reports "Missing parenthesis in
call to print" when folks attempt to run Python 2 code under Python 3.

At the moment, tokenizer and parser errors are some of the most
beginner-hostile ones we offer, since we don't have any real context
when raising them - it's just a naive algorithm saying "This isn't the
text I expected to see next". By contrast, later in the code
generation pipeline, we have more information about what the user was
trying to do, and can usually offer better errors.

What Guido pointed out when I was working on the "print" heuristic is
that we actually get a second go at this: the *exception constructor*
usually has access to the text that the tokenizer or parser couldn't
handle, and since it isn't on the critical performance path for
anything, we can afford to invest some time in looking for common
kinds of errors and try to nudge folks in a better direction when we
think they've tripped over one of them.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia