Front page | perl.perl6.compiler |
Postings from November 2005
On Mon, Nov 07, 2005 at 10:51:59AM -0600, Patrick R. Michaud wrote:
: In p6rules, how should specify characters (glyphs, bytes, whatever)
: using octal notation?
:
: Currently S02 says that integer constants in octal are written with
: as "0o" prefix (as in 0o123), just as we would use the "0x" prefix
: to specify integers using base-16.
:
: It doesn't seem to be written anywhere, but I think it's assumed
: that in string literals one would use "\o123", just as we use
: "\x0a".
That should certainly be permissible even if we don't force it.
And I suspect we should force it. Probably \0123 needs to be
completely illegal, at least for a decade or two, so we can let
our descendents decide what it should mean.
: Should rules work the same -- i.e., use "\o123" to specify a
: character (glyph, byte, whatever) using octal notation?
I believe so.
: And are we officially eliminating the \nnn notation from rules
: and string literals? This seems to be implied by Larry's post at
: http://www.nntp.perl.org/group/perl.perl6.language/19385 , but
: several items in that thread seem to have been dropped without
: a final resolution, or at least haven't made it into a design
: document.
I currently think that, given current trends toward installing whitespace
between tokens, we can reasonably allow \d123 for decimal and require
people to say \d 123 if they mean a digit followed by 123. Of course,
we then have a little problem under :w, which we can solve with \d<null>123.
Maybe <> is short for <null>, and you can write \d<>123. Though
there's always [\d]123 too, which oddly enough is the same as <+[\d]>123
in this case. I wonder how often people would be fooled into thinking
[\d] is a character class...
: It's worth noting that both S05 and A05 make use of the traditional
: \nnn notation in descriptions, and we probably need to update these
: to bring them in line with whatever decision is made.
Yes.
By the way, found an interesting bug in pugs that might or might not
be related:
say +'0012'
prints 0. Should print 12. If someone with time and a commit bit
wants to install a test, I'd be obliged.
Larry
Thread Previous
|
Thread Next