Use the standard
to escape special characters,
in both string literals, and outside.
In general (outside string literals) a
by a non-letter character makes that character be treated as a letter.
\1\+2 is a 3-character identifiers consisting of
even if the languages normally otherwise doesn't allow identifiers
to start with digits or to contain
Letters don't need to be escaped, in either identifiers or names.
So we're free to use
followed by a letter for
other purposes, including the standard C string escapes.
I suggested at least the following:
\xNNNN - A Unicode escape. Terminated by the first
character that is neither a digit or a letter.
If that character is a space, it is ignored.
Only a single space is ignored.
\n - A newline.
The string form of regular expressions should be compatible with this convention.