>
> ruby-mode uses syntax-propertize to make it so that
>
>     config.allow_sites = %w{twitter facebook pinterest linkedin}
>
> is treated somewhat like
>
>     config.allow_sites = "w{twitter facebook pinterest linkedin"
>
> So if you go to the end of the line and try to skip back over the
> previous `sexp` you'll end up in front of the `%` rather than in front
> of the `{`.
>
> The purpose is probably to handle things like:
>
>     config.allow_sites = %w{twitter facebook # pinterest linkedin}
>
> where the `#` would otherwise be taken as the beginning of a comment.
>

Ah right, that makes sense.



> > If I comment out the call to `ruby-syntax-propertize-percent-literal',
> then
> > the bug in evil-surround is gone, and everything just looks the same
> > visually (the percent literals are correctly highlighted).
>
> Not sure what "comment out the call" means exactly, but from my reading
> of the code, it would result in mayhem (the %w{ above would probably
> be highlighted as if he extended to the end of the buffer).
>

What I meant was "if I edit `ruby-syntax-propertize' so it never calls
`ruby-syntax-propertize-percent-literal' at line 1929". But I think you are
right, it would probably break on your example with the comment above.


In order to interact better with things like Evil's
> delimiter-replacement, ruby-mode.el could be changed so that instead of
> marking the opening `%` and the closing `}` with the `|` syntax, it
> would mark the `%` and `w` part with `'` syntax and then arrange to mark
> the inside of the delimited text with an ad-hoc syntax table that
> doesn't treat `#` as a comment started nor `"` as a string delimiter
> (i.e., the same syntax-table used by the `with-syntax-table`
> in `ruby-syntax-propertize-percent-literal`).  Or alternatively, it
> could look for things like `#` and `"` and give them a `.` syntax.


Thank you a lot for the explanation and the suggestion! We'll see what we
can do :-)

Kind regards,
Philippe