Usage of \[oxdb] (was Re: String Literals, take 2)

[Michael Lazzaro]

We still need to verify whether we can have, in qq strings:

\033 - octal (p5; deprecated but allowed in p6?)
\o33 - octal (p5)
\x1b - hex (p5)
\d123 - decimal (?)
\b1001 - binary (?)

and if so, if these are allowed too:

\o{777} - (?)
\x{1b} - "wide" hex (p5)
\d{123} - (?)
\b{1001} - (?)

Only four of these nine constructs are allowed in Perl5.

Note that \b conflicts with backspace. I'd rather keep backspace than binary, personally; I have yet to feel the need to call out a char in binary. :-) Or we can make it dependent on the trailing digits, or require the brackets, or require backspace to be spelt differently.

But I think we'd definitely like to introduce \d.

There is also the question of what the bracketed format does. "Wide" chars, e.g. for Unicode, seem appropriate only in hex. But it would seem useful to allow a bracketed form for the others that prevents ambiguities:

"\o164" ne "\o{16}4"
"\d100" ne "\d{10}0"

Whether that means you can actually specify wide chars in \o, \d, and \b or it's just a disambiguification of the Latin-1 case is open to question.

MikeL

*Not to be confused with an eigendisambiguification, of course.