There are three constructs in the lexer that are obsolete and that issue warning messages when they are used. The first of these is using the
'...' construct as a line continuation inside of a double quoted string. The decision was made in this thread Support line continuations within single-quoted strings? - #7 by rik to deprecate that usage in Octave version 7 and remove it completely in Octave version 9.
Should the other two constructs which are obsolete also be deprecated? They are
'\'as a line continuation character. The issue is that this looks like left division.
octave:1> x = 5 \ warning: using continuation marker \ outside of double quoted strings is deprecated and will be removed from a future version of Octave, use ... instead
- Extra white space characters after line continuation character in double-quoted strings.
str = "abc \ warning: white space and comments after continuation markers in double-quoted character strings are obsolete and will not be allowed in a future version of Octave