Force RVALUE macros when in PERL_DEBUG_COW

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

diff --git a/pod/perlebcdic.pod b/pod/perlebcdic.pod
index 0053d91..942526b 100644 (file)
--- a/pod/perlebcdic.pod
+++ b/pod/perlebcdic.pod
@@ -117,6 +117,24 @@ all the possible code points, pack("U",ord("A")) would in EBCDIC
 equal I<A with acute> or chr(101), and unpack("U", "A") would equal
 65, or I<non-breaking space>, not 193, or ord "A".)
 
+=head2 Remaining Perl Unicode problems in EBCDIC
+
+=over 4
+
+=item *
+
+Many of the remaining seem to be related to case-insensitive matching:
+for example, C<< /[\x{131}]/ >> (LATIN SMALL LETTER DOTLESS I) does
+not match "I" case-insensitively, as it should under Unicode.
+(The match succeeds in ASCII-derived platforms.)
+
+=item *
+
+The extensions Unicode::Collate and Unicode::Normalized are not
+supported under EBCDIC, likewise for the encoding pragma.
+
+=back
+
 =head2 Unicode and UTF
 
 UTF is a Unicode Transformation Format.  UTF-8 is a Unicode conforming
@@ -150,6 +168,27 @@ and from Latin-1 code points to EBCDIC code points
 For doing I/O it is suggested that you use the autotranslating features
 of PerlIO, see L<perluniintro>.
 
+Since version 5.8 Perl uses the new PerlIO I/O library.  This enables
+you to use different encodings per IO channel.  For example you may use
+
+    use Encode;
+    open($f, ">:encoding(ascii)", "test.ascii");
+    print $f "Hello World!\n";
+    open($f, ">:encoding(cp37)", "test.ebcdic");
+    print $f "Hello World!\n";
+    open($f, ">:encoding(latin1)", "test.latin1");
+    print $f "Hello World!\n";
+    open($f, ">:encoding(utf8)", "test.utf8");
+    print $f "Hello World!\n";
+
+to get two files containing "Hello World!\n" in ASCII, CP 37 EBCDIC,
+ISO 8859-1 (Latin-1) (in this example identical to ASCII) respective
+UTF-EBCDIC (in this example identical to normal EBCDIC).  See the
+documentation of Encode::PerlIO for details.
+
+As the PerlIO layer uses raw IO (bytes) internally, all this totally
+ignores things like the type of your filesystem (ASCII or EBCDIC).
+
 =head1 SINGLE OCTET TABLES
 
 The following tables list the ASCII and Latin 1 ordered sets including
@@ -625,13 +664,13 @@ it in tr/// like so:
     '\060\061\062\063\064\065\066\067\070\071\263\333\334\331\332\237' ;
 
     my $ebcdic_string = $ascii_string;
-    eval '$ebcdic_string =~ tr/\000-\377/' . $cp_037 . '/';
+    eval '$ebcdic_string =~ tr/' . $cp_037 . '/\000-\377/';
 
 To convert from EBCDIC 037 to ASCII just reverse the order of the tr/// 
 arguments like so:
 
     my $ascii_string = $ebcdic_string;
-    eval '$ascii_string = tr/' . $cp_037 . '/\000-\377/';
+    eval '$ascii_string =~ tr/\000-\377/' . $cp_037 . '/';
 
 Similarly one could take the output of the third column from recipe 0 to
 obtain a C<$cp_1047> table.  The fourth column of the output from recipe
@@ -819,7 +858,11 @@ As of perl 5.005_03 the letter range regular expression such as
 [A-Z] and [a-z] have been especially coded to not pick up gap 
 characters.  For example, characters such as E<ocirc> C<o WITH CIRCUMFLEX> 
 that lie between I and J would not be matched by the 
-regular expression range C</[H-K]/>.  
+regular expression range C</[H-K]/>.  This works in
+the other direction, too, if either of the range end points is
+explicitly numeric: C<[\x89-\x91]> will match C<\x8e>, even
+though C<\x89> is C<i> and C<\x91 > is C<j>, and C<\x8e>
+is a gap character from the alphabetic viewpoint.
 
 If you do want to match the alphabet gap characters in a single octet 
 regular expression try matching the hex or octal code such 
@@ -1226,12 +1269,16 @@ Legacy multi byte EBCDIC code pages XXX.
 There may be a few system dependent issues 
 of concern to EBCDIC Perl programmers.
 
-=head2 OS/400 
-
-The PASE environment.
+=head2 OS/400
 
 =over 8
 
+=item PASE
+
+The PASE environment is runtime environment for OS/400 that can run
+executables built for PowerPC AIX in OS/400, see L<perlos400>.  PASE
+is ASCII-based, not EBCDIC-based as the ILE.
+
 =item IFS access
 
 XXX.