Add more known sprintf failures.

[p5sagit/p5-mst-13.2.git] / pod / perlunicode.pod

diff --git a/pod/perlunicode.pod b/pod/perlunicode.pod
index c9954d8..b8bbc57 100644 (file)
--- a/pod/perlunicode.pod
+++ b/pod/perlunicode.pod
@@ -10,13 +10,14 @@ WARNING: The implementation of Unicode support in Perl is incomplete.
 
 The following areas need further work.
 
-=over
+=over 4
 
 =item Input and Output Disciplines
 
 There is currently no easy way to mark data read from a file or other
 external source as being utf8.  This will be one of the major areas of
-focus in the near future.
+focus in the near future.  Unfortunately it is unlikely that the Perl
+5.6 and earlier will ever gain this capability.
 
 =item Regular Expressions
 
@@ -66,7 +67,8 @@ or from literals and constants in the source text.
 If the C<-C> command line switch is used, (or the ${^WIDE_SYSTEM_CALLS}
 global flag is set to C<1>), all system calls will use the
 corresponding wide character APIs.  This is currently only implemented
-on Windows.
+on Windows as other platforms do not have a unified way of handling
+wide character APIs.
 
 Regardless of the above, the C<bytes> pragma can always be used to force
 byte semantics in a particular lexical scope.  See L<bytes>.
@@ -127,8 +129,7 @@ attempt to canonicalize variable names for you.)
 
 Regular expressions match characters instead of bytes.  For instance,
 "." matches a character instead of a byte.  (However, the C<\C> pattern
-is provided to force a match a single byte ("C<char>" in C, hence
-C<\C>).)
+is available to force a match a single byte ("C<char>" in C, hence C<\C>).)
 
 =item *
 
@@ -198,13 +199,28 @@ byte-oriented C<chr()> and C<ord()> under utf8.
 
 =item *
 
+The bit string operators C<& | ^ ~> can operate on character data.
+However, for backward compatibility reasons (bit string operations
+when the characters all are less than 256 in ordinal value) one cannot
+mix C<~> (the bit complement) and characters both less than 256 and
+equal or greater than 256.  Most importantly, the DeMorgan's laws
+(C<~($x|$y) eq ~$x&~$y>, C<~($x&$y) eq ~$x|~$y>) won't hold.
+Another way to look at this is that the complement cannot return
+B<both> the 8-bit (byte) wide bit complement, and the full character
+wide bit complement.
+
+=item *
+
 And finally, C<scalar reverse()> reverses by character rather than by byte.
 
 =back
 
 =head2 Character encodings for input and output
 
-[XXX: This feature is not yet implemented.]
+This feature is in the process of getting implemented.
+
+(For Perl 5.6 and earlier the support is unlikely to get integrated
+to the core language and some external module will be required.)
 
 =head1 CAVEATS