Turning `header` patterns into `signature` patterns in all syntax files
was a mistake. The two are different things. In almost all syntax files
those patterns are things like shebangs or <?xml ... ?> or
<!DOCTYPE html5> i.e. things that:
1. can be (and should be) used for detecting the filetype when there is
no `filename` match (and that is actually the purpose of those
patterns, so it's a regression that it doesn't work anymore).
2. should only occur in the first line of the file, not in the first
100 lines or so.
In other words, the old `header` semantics was exactly what was needed
for those filetypes, while the new `signature` semantics makes little
sense for them.
So replace `signature` back with `header` in most syntax files. Keep
`signature` only in C++ and Objective-C syntax files, for which it was
actually introduced.
1. Python decorators begin a compound statement, so they only appear
at the start of a line. So match at the line start to avoid giving
decorator colors to matrix multiplication (@) expressions. Source:
https://docs.python.org/3/reference/compound_stmts.html#function-definitions
2. Python decorators go to the end of the line and might not include
parentheses (for example @functools.cache). So instead of matching
everything until an `(`, just match as many non-`(` characters
as possible---which both catches the @functools.cache example and
allows decorator parameters to fall back to the default color.
3. Instead of hardcoding `brightgreen` (which railscast.micro also
complains about), color decorators as `preproc` (otherwise unused
by the python syntax files, and arguably the right colorscheme
group to be using for syntactic sugars anyway). Note this will
change decorator colors---for example from bright green to kinda
brown on monokai, and from yellow to more of a light orange on
railscast.
* Python syntax: multiline string should be comment.string, not comment
''' delimits multiline strings, not comments
* Python syntax: multiline string should be comment.string, not comment
''' delimits multiline strings, not comments
* Update python3.yaml for python3.10 keywords
The python3 syntax had "filename" instead of "filetype"
as the header. This commit also makes standard py extensions
use the python3 highlighting and requires .py2 or a python2
env to use python2 highlighting because python3 is the standard
python now.
Fixes#1592
Use the 'regexp2' library for lookahead and lookbehind in region
start and end regular expressions to support things like closing quotes
that aren't preceded by backslashes.