Raw string highlighting

[jcrmatos]

Environment data

VS Code version: 1.18.1
Python Extension version: 0.80.0
Python Version: CPython 3.5.4 32b
OS and version: Windows 7 Pro SP1 x64

Actual behavior

I have the following line

fops.save_txt(environ['SystemRoot'] + r'\explorer.exe '
                      + bdexp.EXPORTS_DIR,
                      bpl.PROGS_TO_LAUNCH_PN)

and the r and \e shows in blue with the first ' and xplorer.exe ' shows in brown(?).
My point is that it isn't recognizing it as a string (raw in this case) like it does with the previous 'SystemRoot' which shows all brown(?) and the Intellisense recognizes as a string.

Expected behavior

It should show r'\explorer.exe ' all brown(?) and recognize it as a string.

I reported this first in VS Code Python at microsoft/vscode-python#337 (comment) but Brett Cannon told me to open it here because their syntax highlighting depends on MagicPython.

Thanks,

JM

[elprans]

This is a feature.

foo = r'\nregexp'  # this is parsed as a "regexp-string"
bar = R'\nregexp'  # this is parsed as a raw string

[jcrmatos]

Hello,

I'm sorry but I can't find that difference in the CPython spec.
In fact what I find in both Py2 and Py3 official docs is:

Both string and bytes literals may optionally be prefixed with a letter 'r' or 'R'; such strings are called raw strings and treat backslashes as literal characters.

...

Unless an 'r' or 'R' prefix is present, escape sequences in string and bytes literals are interpreted according to rules similar to those used by Standard C.

Please reconsider changing MagicPython behavior to be in sync with CPython.

Thanks,

JM

[jcrmatos]

Hello,

I forgot to include the CPython official docs links:
https://docs.python.org/3/reference/lexical_analysis.html
and
https://docs.python.org/2/reference/lexical_analysis.html

Thanks,

JM

[1st1]

Please reconsider changing MagicPython behavior to be in sync with CPython.

You're correct—there's no "regex" literal in Python, and r"string" is the same thing as R"string". However, TextMate originally, and Sublime Text later both highlighted r"strings" as regular expressions for years, and a lot of users expect MagicPython to do the same, as it's positioned as a "drop in replacement" for Python syntax highlighters in those editors. Therefore, unfortunately, we are not going to reconsider having this feature in MagicPython.

[jcrmatos]

Hello,

I understand.
Can I ask you please to add a Settings option to disable that behavior?

Thanks,

JM

[1st1]

Generally syntax highlighters don't have settings panels and aren't configurable. We had an idea how to do that for MP, but don't have time to pursue it. So unfortunately there's no ETA for this feature.

[vors]

This "feature" is super confusing and annoying, please consider dropping it.

[memeplex]

There is a problem with the approach here that was not mentioned: it doesn't play well with the super popular black code formatter, which will turn R into r again.

[elprans]

Black can be told not to do that via --skip-string-normalization