@U attempt

[Karl Berry]

So, I attempted to implement @U (didn't do the user documentation or
tests yet).  What I did seems to get the right output, but I confess I'm
not at all sure I did the right thing -- especially to get the text of
the argument.  I read the pod docs that I could find, but probably
missed some crucial stuff; the elements of the overall tree+list data
structure remain opaque to me, I'm afraid.  Patrice, if you wrote up
some overall documentation about that, please send a pointer.

Also, I just assumed the arg would be literal hex digits, that is, not
supporting things like @address@hidden or @address@hidden  I
know the code could easily handle such, but I felt like enough time had
passed already without delving into that.

Below are the important diffs (not in applyable form; I committed the
actual changes).  Patrice, if you could give it a quick look, that would
be greatly appreciated.  If I'm totally on the wrong track, just say so,
and I'll revert it and we won't have @U in the forthcoming release.  Not
the end of the world.

Thanks,
Karl

--- tp/Texinfo/Common.pm        (revision 6107)
+++ tp/Texinfo/Common.pm        (working copy)
@@ -599,9 +602,8 @@
 
-foreach my $one_arg_command (
-  'ctrl','dmn', 'w', 'key',
-  'titlefont','hyphenation','anchor','errormsg') {
+foreach my $one_arg_command ('U', 'ctrl', 'dmn', 'w', 'key',
+    'titlefont', 'hyphenation', 'anchor', 'errormsg') {
   $brace_commands{$one_arg_command} = 1;
 }
 
--- tp/Texinfo/Parser.pm        (revision 6107)
+++ tp/Texinfo/Parser.pm        (working copy)
@@ -436,10 +437,10 @@
 
-foreach my $command ('titlefont', 'anchor', 'xref','ref','pxref', 
+foreach my $command ('titlefont', 'anchor', 'xref','ref', 'pxref', 
                      'inforef', 'shortcaption', 'math', 'indicateurl',
                      'email', 'uref', 'url', 'image', 'abbr', 'acronym', 
-                     'dmn', 'ctrl', 'errormsg') {
+                     'dmn', 'ctrl', 'errormsg', 'U') {
   $simple_text_commands{$command} = 1;
 }

--- tp/Texinfo/Convert/HTML.pm  (revision 6107)
+++ tp/Texinfo/Convert/HTML.pm  (working copy)
@@ -1831,9 +1831,36 @@

+sub _convert_U_command($$$$)
+{
+  my $self = shift;
+  my $cmdname = shift;
+  my $command = shift;
+  my $args = shift;
+  my $res;
+
+  my $text = $args->[0]->{'normal'};
+  # these tests should be in the parser; duplicated in Plaintext.pm
+  if (!defined($text) || !$text) {
+    $self->line_warn($self->__("no argument specified for address@hidden"),
+                     $command->{'line_nr'});
+    $res = '';
+
+  } elsif ($text !~ /^[0-9A-Fa-f]+$/) {
+    $self->line_error(
+      sprintf($self->__("non-hex digits in argument for address@hidden: %s"), 
$text),
+      $command->{'line_nr'});
+    $res = '';
+
+  } else {
+    $res = "&#x$text;"; # ok
+  }
+  return $res;
+}
+$default_commands_conversion{'U'} = \&_convert_U_command;
+
 sub _default_comment($$) {
   my $self = shift;
   my $text = shift;

--- tp/Texinfo/Convert/Plaintext.pm     (revision 6107)
+++ tp/Texinfo/Convert/Plaintext.pm     (working copy)
@@ -2185,6 +2186,32 @@
       $self->_add_text_count($result);
       $self->_add_lines_count(2);
       return $result;
+
+    } elsif ($command eq 'U') {
+      my $arg = $root->{'extra'}->{'brace_command_contents'}
+                ->[0]->[0]->{'text'};
+      my $res;
+      # these tests should be in the parser; duplicated in HTML.pm
+      if (!defined($arg) || !$arg) {
+        $self->line_warn($self->__("no argument specified for address@hidden"),
+                         $root->{'line_nr'});
+        $res = '';
+
+      } elsif ($arg !~ /^[0-9A-Fa-f]+$/) {
+        $self->line_error(
+          sprintf($self->__("non-hex digits in argument for address@hidden: 
%s"), $arg),
+          $root->{'line_nr'});
+        $res = '';
+
+      } else {
+        # binary if utf-8 being output, else ascii.
+        $res = $self->{'to_utf8'} ? chr(hex($arg)) : "U+$arg";
+      }
+
+      $result .= $self->_count_added($formatter->{'container'}, 
+                 $formatter->{'container'}->add_text($res, $res)); 
+      return $result;
+
     } elsif ($command eq 'value') {
       my $expansion = $self->gdt('@{No value for `{value}\'@}', 
                                     {'value' => $root->{'type'}});

--- tp/Texinfo/Convert/DocBook.pm       (revision 6107)
+++ tp/Texinfo/Convert/DocBook.pm       (working copy)
@@ -1069,6 +1072,19 @@
         } else {
           return '';
         }
+
+      } elsif ($root->{'cmdname'} eq 'U') {
+        my $argument = $root->{'extra'}->{'brace_command_contents'}->[0]
+                       ->[0]->{'text'};
+        if (defined($argument) && $argument) {
+          $result = "&#x$argument;";
+        } else {
+          $self->line_warn($self->__("no argument specified for 
address@hidden"),
+                           $root->{'line_nr'});
+          $result = '';
+        }
+        return $result;
+
       } elsif ($Texinfo::Common::inline_commands{$root->{'cmdname'}}) {
         my $expand = 0;
         if ($Texinfo::Common::inline_format_commands{$root->{'cmdname'}}) {