On Wed, Dec 04, 2002 at 11:38:35AM -0800, Michael Lazzaro wrote:
: We still need to verify whether we can have, in qq strings:
:
: \033 - octal (p5; deprecated but allowed in p6?)
I think it's disallowed.
: \o33 - octal (p5)
: \x1b - hex (p5)
: \d123 - decimal (?)
: \b1001 - binary (?)
Can't really have \d and \b if they keep their current regex meanings.
I think the general form is:
\0o33 - octal
\0x1b - hex
\0d123 - decimal
\0b1001 - binary
\x and \o are then just shortcuts.
: and if so, if these are allowed too:
:
: \o{777} - (?)
: \x{1b} - "wide" hex (p5)
: \d{123} - (?)
: \b{1001} - (?)
The general form could be
\0o[33] - octal
\0x[1b] - hex
\0d[123] - decimal
\0b[1001] - binary
Or it could be
\c[0o33] - octal
\c[0x1b] - hex
\c[0d123] - decimal
\c[0b1001] - binary
since \c is taking over \N's (rather ill-defined) duties.
: 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.
\c[^H], for instance. We can overload the \c notation to our heart's
desire, as long as we don't conflict with its use for named characters:
\c[GREEK CAPITAL LETTER OMEGA WITH PSILI AND PERISPOMENI AND PROSGEGRAMMENI]
: But I think we'd definitely like to introduce \d.
Can't, unless we change \d to <digit> in regexen.
: 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.
There ain't no such thing as a "wide" character. \xff is exactly
the same character as \x[ff]. A character in Perl is an abstract
codepoint number--how it's represented is of no concern to the
programmer (though it might be of concern to any interface to the
outside world, of course). Do not think of Perl 6 strings as arrays
of bytes (except when they are (and probably not even then...)).
Larry
