Re: Shortcut for \repeat unfold

[Hans Åberg]

> On 25 Sep 2021, at 19:25, Werner LEMBERG <wl@gnu.org> wrote:
> 
>>>> Perhaps the LilyPond syntax might be tweaked so that identifiers
>>>> starting with a UTF-8 multi-byte (high bit set) character do not
>>>> need the backslash.  Then simply ×2 would look good.
>>> 
>>> This reminds me of TeX's 'active characters'.  I think we shouldn't
>>> go this route.  IMHO, a command should always be introduced with a
>>> backslash.
>> 
>> The idea here is different, it is for identifiers, and in the input
>> syntax only, does not change the internal semantics at all.  It is
>> good not having to type backslash when a command is used.
> 
> Really?  I highly doubt that.  In particular, what about lyrics mode?

The idea would be to change the file lexer.ll by adding U and UCOMMAND:
A               [a-zA-Z\200-\377]
U               [\200-\377]
AA              {A}|_
N               [0-9]
ANY_CHAR        (.|\n)
SYMBOL          {A}([-_]{A}|{A})*
COMMAND         \\{SYMBOL}
UCOMMAND        {U}{SYMBOL}

Then in select places, that is context switches, add {UCOMMAND}:
        {COMMAND}       {
                return scan_escaped_word (YYText_utf8 () + 1); 
        }
        {UCOMMAND}      {
                return scan_escaped_word (YYText_utf8 ());
        }