perl-xml-commits

[Grant M. <gr...@us...>]

Update of /cvsroot/perl-xml/perl-xml-faq
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv18818

Modified Files:
	perl-xml-faq.xml 
Log Message:
- added Q&A re 'use utf8;' in 5.8

Index: perl-xml-faq.xml
===================================================================
RCS file: /cvsroot/perl-xml/perl-xml-faq/perl-xml-faq.xml,v
retrieving revision 1.18
retrieving revision 1.19
diff -u -d -r1.18 -r1.19
--- perl-xml-faq.xml	11 Nov 2004 08:57:33 -0000	1.18
+++ perl-xml-faq.xml	11 Nov 2004 09:25:15 -0000	1.19
@@ -1401,7 +1401,7 @@
       </formalpara>
 
       <programlisting><![CDATA[
-use utf8;
+use utf8;   # Only needed for 5.6, not 5.8 or later
 
 s/([\x{80}-\x{FFFF}])/'&#' . ord($1) . ';'/gse;
 	]]></programlisting>
@@ -1413,8 +1413,8 @@
 s/([^\x20-\x7F])/'&#' . ord($1) . ';'/gse;
 	]]></programlisting>
 
-      <para>This version does not require 'use utf8'; does not require a
-      version of Perl which recognises \x{NN} and handles characters
+      <para>This version does not require 'use utf8' with Perl 5.6; does not
+      require a version of Perl which recognises \x{NN} and handles characters
       outside the 0x80-0xFFFF range.</para>
 
       <para>Even if you are outputting Latin1, you will need to use a technique
@@ -1495,7 +1495,7 @@
       </formalpara>
 
       <programlisting><![CDATA[
-use utf8;
+use utf8;  # Not required with 5.8 or later
 
 my $u_city = "S\x{E3}o Paulo";
 my $l_city = pack("C*", unpack('U*', $u_city));
@@ -1581,6 +1581,33 @@
 
   </qandaentry>
 
+  <qandaentry id="use_utf8">
+    <question>
+      <para>What does 'use utf8;' do?</para>
+    </question>
+
+    <answer>
+
+      <para>In Perl 5.8 and later, the sole use of the 'use utf8;' pragma is to
+      tell Perl that your script is written in UTF-8 (ie: any non-ASCII or
+      multibyte characters should be interpreted as UTF-8).  So if your code is
+      plain ASCII, you don't need the pragma.</para>
+
+      <para>The original UTF8 support in Perl 5.6 required the pragma to
+      enable wide character support for builtin functions (such as length) 
+      and the regular expression engine.  This is no longer necessary in 5.8
+      since Perl automatically uses character rather than byte semantics
+      with strings that have the utf8 flag set.</para>
+
+      <para>You can find out more about how Unicode handling changed in
+      Perl 5.8 from the <ulink
+      url="http://search.cpan.org/dist/perl/pod/perl58delta.pod">perl58delta.pod</ulink>
+      file that ships with Perl.</para>
+
+    </answer>
+
+  </qandaentry>
+
   <qandaentry id="encoding_common">
     <question>
       <para>What are some commonly encountered problems with encodings?</para>