Upgrade to Math::BigInt 1.45; from Tels.

[perl5.git] / lib / utf8.pm

diff --git a/lib/utf8.pm b/lib/utf8.pm
index d9e9bec..cb19686 100644 (file)
--- a/lib/utf8.pm
+++ b/lib/utf8.pm
@@ -1,17 +1,22 @@
 package utf8;
 
+$utf8::hint_bits = 0x00800000;
+
+our $VERSION = '1.00';
+
 sub import {
-    $^H |= 0x00800000;
+    $^H |= $utf8::hint_bits;
     $enc{caller()} = $_[1] if $_[1];
 }
 
 sub unimport {
-    $^H &= ~0x00800000;
+    $^H &= ~$utf8::hint_bits;
 }
 
 sub AUTOLOAD {
     require "utf8_heavy.pl";
-    goto &$AUTOLOAD;
+    goto &$AUTOLOAD if defined &$AUTOLOAD;
+    Carp::croak("Undefined subroutine $AUTOLOAD called");
 }
 
 1;
@@ -19,7 +24,7 @@ __END__
 
 =head1 NAME
 
-utf8 - Perl pragma to enable/disable UTF-8 in source code
+utf8 - Perl pragma to enable/disable UTF-8 (or UTF-EBCDIC) in source code
 
 =head1 SYNOPSIS
 
@@ -28,13 +33,10 @@ utf8 - Perl pragma to enable/disable UTF-8 in source code
 
 =head1 DESCRIPTION
 
-WARNING: The implementation of Unicode support in Perl is incomplete.
-Expect sudden and unannounced changes!
-
 The C<use utf8> pragma tells the Perl parser to allow UTF-8 in the
-program text in the current lexical scope.  The C<no utf8> pragma
-tells Perl to switch back to treating the source text as literal
-bytes in the current lexical scope.
+program text in the current lexical scope (allow UTF-EBCDIC on EBCDIC based
+platforms).  The C<no utf8> pragma tells Perl to switch back to treating 
+the source text as literal bytes in the current lexical scope.
 
 This pragma is primarily a compatibility device.  Perl versions
 earlier than 5.6 allowed arbitrary bytes in source code, whereas
@@ -42,34 +44,55 @@ in future we would like to standardize on the UTF-8 encoding for
 source text.  Until UTF-8 becomes the default format for source
 text, this pragma should be used to recognize UTF-8 in the source.
 When UTF-8 becomes the standard source format, this pragma will
-effectively become a no-op.
+effectively become a no-op.  For convenience in what follows the
+term I<UTF-X> is used to refer to UTF-8 on ASCII and ISO Latin based
+platforms and UTF-EBCDIC on EBCDIC based platforms.
 
-Enabling the C<utf8> pragma has the following effects:
+Enabling the C<utf8> pragma has the following effect:
 
-=over
+=over 4
 
 =item *
 
 Bytes in the source text that have their high-bit set will be treated
-as being part of a literal UTF-8 character.  This includes most literals
-such as identifiers, string constants, constant regular expression patterns
-and package names.
+as being part of a literal UTF-8 character.  This includes most
+literals such as identifiers, string constants, constant regular
+expression patterns and package names.  On EBCDIC platforms characters
+in the Latin 1 character set are treated as being part of a literal
+UTF-EBCDIC character.
 
-=item *
+=back
+
+=head2 Utility functions
+
+The following functions are defined in the C<utf8::> package by the perl core.
+
+=over 4
+
+=item * $num_octets = utf8::upgrade($string);
+
+Converts internal representation of string to the Perl's internal
+I<UTF-X> form.  Returns the number of octets necessary to represent
+the string as I<UTF-X>.
+
+=item * utf8::downgrade($string[, CHECK])
+
+Converts internal representation of string to be un-encoded bytes.
+
+=item * utf8::encode($string)
+
+Converts (in-place) I<$string> from logical characters to octet sequence
+representing it in Perl's I<UTF-X> encoding.
+
+=item * $flag = utf8::decode($string)
 
-In the absence of inputs marked as UTF-8, regular expressions within the
-scope of this pragma will default to using character semantics instead
-of byte semantics.
+Attempts to convert I<$string> in-place from Perl's I<UTF-X> encoding
+into logical characters.
 
-    @bytes_or_chars = split //, $data; # may split to bytes if data
-                                       # $data isn't UTF-8
-    {
-       use utf8;                       # force char semantics
-       @chars = split //, $data;       # splits characters
-    }
+=back
 
 =head1 SEE ALSO
 
-L<perlunicode>, L<byte>
+L<perlunicode>, L<bytes>
 
 =cut