On 4 November 2016 at 08:36, Simon Cross <hodgestar+python...@gmail.com> wrote: > On Fri, Nov 4, 2016 at 9:56 AM, Eric V. Smith <e...@trueblade.com> wrote: >> 2. The parser sees that it's an f-string, and breaks it into expression and >> text parts. > > I'm with Fabio here. It would be really nice to have a grammar > specified and documented for this step, even if it's not implemented > that way. Otherwise it's going to be very hard for, e.g., syntax > highlighters to know what is intended to be allowed.
I think that if the docs explain the process, essentially as noted by Eric above: > Step 2 is the part that limits what types of expressions are allowed. > While scanning for the end of an expression, it stops at the first '!', ':', > or '}' that > isn't inside of a string and isn't nested inside of parens, braces, and > brackets. [...] > Also, backslashes are not allowed anywhere inside of the expression. then that would be fine. Possibly a bit more detail would be helpful, but I'm pretty sure I could reimplement the behaviour (for a syntax highlighter, for example) based on the above. I assume that the open item Eric mentions to fix the PEP and docs is sufficient to cover this, so it'll be documented in due course. Paul _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
