[PATCH rfc] check-code: detect r'...\'...'

[Matt Mackall]

On Wed, 2011-11-09 at 18:19 +0100, Martin Geisler wrote:
> Mads Kiilerich <mads at kiilerich.com> writes:
> 
> > On 11/09/2011 03:31 PM, Matt Mackall wrote:
> >> On Wed, 2011-11-09 at 02:37 +0100, Mads Kiilerich wrote:
> >>> # HG changeset patch
> >>> # User Mads Kiilerich<mads at kiilerich.com>
> >>> # Date 1320802647 -3600
> >>> # Node ID 20fe74e6bcd0518b108f85270c880f330963c490
> >>> # Parent  de7e2fba4326cad80bda0cb100d2ae2f58e67ee8
> >>> check-code: detect r'...\'...'
> >>
> >> Not sure why this matters:
> >>
> >>>>> a = r'x\'x'
> >>>>> b = 'x\'x'
> >>>>> a == b
> >> False
> >>>>> b.replace(a, 'foo') # shouldn't work
> >> "x'x"
> >>>>> import re
> >>>>> re.sub(a, 'foo', b) # should work
> >> 'foo'
> >>
> >> Despite the fact that r'x\'x' is really "x\\'x", the regex engine
> >> turns "\\'" back into a "'" and the expression functions as expected.
> >
> > You are right. Assuming the raw strings are used as regexp then it for
> > all(?) practical purposes doesn't matter that there are extra \'s in
> > the string. It just looks confusing and sloppy, IMHO.
> 
> I agree on the sloppiness.
> 
> But there's also another small reason when it comes to docstrings:
> they're extracted by i18n/hggettext and to add line numbers to the .po
> file, it searches for the docstring in the original .py file. If there
> are extra backslashes in the docstring, then it cannot find the
> docstring and so it defaults to a line number of 1.

Do we have docstrings prefixed with 'r'?

-- 
Mathematics is the supreme nostalgia of our time.