Implement support for character classes.

This patch uses standard C++ headers, contrary to the rest of groff.
Ideally, everything in groff should be updated to do the same.

* src/include/font.h (glyph_to_unicode): New function.

* src/libs/libgroff/font.cpp (glyph_to_unicode): Implement it.
(font::contains, font::get_code): Use it.

* src/roff/troff/charinfo.h: Include <vector> and <utility>.
(charinfo): New members `ranges' and `nested_classes'.
New member functions `get_unicode_code' and `get_flags'.
New member functions `add_to_class', `is_class', and `contains'.
(charinfo::overlaps_horizontally, charinfo::overlaps_vertically,
charinfo::can_break_before, charinfo::can_break_after,
charinfo::can_break_after, charinfo::ends_sentence,
charinfo::transparent,, charinfo:ignore_hcodes): Use `get_flags',
which handles character classes also.

* src/roff/troff/input.cpp (char_class_dictionary): New global
variable.
(define_class): New function.
(init_input_requests): Register `class'.

(charinfo::get_unicode_code, charinfo::get_flags,
charinfo::contains): Implement it.

* NEWS, doc/groff.texinfo (Character Classes), man/groff_diff.man,
man/groff.man: Document it.

9 files changed, 446 insertions, 109 deletions

diff --git a/ChangeLog b/ChangeLog
index d59fd991..e47e1a0b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,37 @@
+2010-12-06  Colin Watson  <cjwatson@debian.org>
+	    Daiki Ueno  <ueno@unixuser.org>
+
+	Implement support for character classes.
+
+	This patch uses standard C++ headers, contrary to the rest of groff. 
+	Ideally, everything in groff should be updated to do the same.
+
+	* src/include/font.h (glyph_to_unicode): New function.
+
+	* src/libs/libgroff/font.cpp (glyph_to_unicode): Implement it.
+	(font::contains, font::get_code): Use it.
+
+	* src/roff/troff/charinfo.h: Include <vector> and <utility>.
+	(charinfo): New members `ranges' and `nested_classes'.
+	New member functions `get_unicode_code' and `get_flags'.
+	New member functions `add_to_class', `is_class', and `contains'.
+	(charinfo::overlaps_horizontally, charinfo::overlaps_vertically,
+	charinfo::can_break_before, charinfo::can_break_after,
+	charinfo::can_break_after, charinfo::ends_sentence,
+	charinfo::transparent,, charinfo:ignore_hcodes): Use `get_flags',
+	which handles character classes also.
+
+	* src/roff/troff/input.cpp (char_class_dictionary): New global
+	variable.
+	(define_class): New function.
+	(init_input_requests): Register `class'.
+
+	(charinfo::get_unicode_code, charinfo::get_flags,
+	charinfo::contains): Implement it.
+
+	* NEWS, doc/groff.texinfo (Character Classes), man/groff_diff.man,
+	man/groff.man: Document it.
+
 2010-11-11  Anton Shepelev  <anton.txt@gmail.com>
 
 	[grohtml]: Improve texinfo documentation.
diff --git a/NEWS b/NEWS
index c5028c4b..00a41b47 100644
--- a/NEWS
+++ b/NEWS
@@ -24,6 +24,10 @@ o There is a new warning category `file', enabled by default.  The `mso'
   request emits warnings in this category when the requested macro file does
   not exist.
 
+o The new `class' request assigns a short name to a set of characters
+  which can be referred to in the `cflags' request.  This is especially
+  useful to control line-breaking and hyphenation rules in CJK languages.
+
 Tbl
 ---
 
diff --git a/doc/groff.texinfo b/doc/groff.texinfo
index 8d2e5c68..42cf6166 100644
--- a/doc/groff.texinfo
+++ b/doc/groff.texinfo
@@ -6052,7 +6052,7 @@ aaa bbb ccc ddd eee fff ggg hhh\h'0'\R':k \n[.k]'
 @endExample
 
 If you process this with the PostScript device (@code{-Tps}), there
-will be a line break eventually after @code{ggg} in both input lines. 
+will be a line break eventually after @code{ggg} in both input lines.
 However, after processing the space after @code{ggg}, the partially
 collected line is not overfull yet, so @code{troff} continues to
 collect input until it sees the space (or in this case, the newline)
@@ -8726,6 +8726,7 @@ special symbols (Greek, mathematics).
 * Font Families::
 * Font Positions::
 * Using Symbols::
+* Character Classes::
 * Special Fonts::
 * Artificial Fonts::
 * Ligatures and Kerning::
@@ -9122,7 +9123,7 @@ this is font 1 again
 
 @c ---------------------------------------------------------------------
 
-@node Using Symbols, Special Fonts, Font Positions, Fonts and Symbols
+@node Using Symbols, Character Classes, Font Positions, Fonts and Symbols
 @subsection Using Symbols
 @cindex using symbols
 @cindex symbols, using
@@ -9458,7 +9459,9 @@ width, depth, and height, nothing else.  All manipulations with the
 modified with the @code{cflags} request.  The first argument is the sum
 of the desired flags and the remaining arguments are the characters or
 symbols to have those properties.  It is possible to omit the spaces
-between the characters or symbols.
+between the characters or symbols.  Instead of single characters or
+symbols you can also use character classes (see @ref{Character Classes}
+for more details).
 
 @table @code
 @item 1
@@ -9639,7 +9642,83 @@ The request @code{rfschar} removes glyph definitions defined with
 
 @c ---------------------------------------------------------------------
 
-@node Special Fonts, Artificial Fonts, Using Symbols, Fonts and Symbols
+@node Character Classes, Special Fonts, Using Symbols, Fonts and Symbols
+@subsection Character Classes
+@cindex character classes
+@cindex classes, character
+
+Classes are particularly useful for East Asian languages such as
+Chinese, Japanese, and Korean, where the number of needed characters is
+much larger than in European languages, and where large sets of
+characters share the same properties.
+
+@Defreq {class, n c1 c2 @dots{}}
+@cindex character class (@code{class})
+@cindex defining character class (@code{class})
+@cindex class of characters (@code{class})
+In @code{groff}, a @dfn{character class} (or simply ``class'') is a set
+of characters, grouped by some user aspect.  The @code{class} request
+defines such classes so that other requests can refer to all characters
+belonging to this set with a single class name.  Currently, only the
+@code{cflags} request can handle character classes.
+
+A @code{class} request takes a class name followed by a list of
+entities.  In its simplest form, the entities are characters or symbols:
+
+@Example
+.class [prepunct] , : ; > @}
+@endExample
+
+Since class and glyph names share the same namespace, it is recommended
+to start and end the class name with @code{[} and @code{]},
+respectively, to avoid collisions with normal @code{groff} symbols (and
+symbols defined by the user).  In particular, the presence of @code{]}
+in the symbol name intentionally prevents the usage of @code{\[...]},
+thus you must use the @code{\C} escape to access a class with such a
+name.
+
+@cindex GGL (groff glyph list)
+@cindex groff glyph list (GGL)
+You can also use a special character range notation, consisting of a
+start character or symbol, followed by @samp{-}, and an end character or
+symbol.  Internally, @code{gtroff} converts these two symbol names to
+Unicode values (according to the groff glyph gist) which then give the
+start and end value of the range.  If that fails, the class definition
+is skipped.
+
+Finally, classes can be nested, too.  
+
+Here is a more complex example:
+
+@Example
+.class [prepunctx] \C'[prepunct]' \[u2013]-\[u2016]
+@endExample
+
+The class @samp{prepunctx} now contains the contents of the class
+@code{prepunct} as defined above (the set @samp{, : ; > @}}), and
+characters in the range between @code{U+2013} and @code{U+2016}.
+
+If you want to add @samp{-} to a class, it must be the first character
+value in the argument list, otherwise it gets misinterpreted as a range.
+
+Note that it is not possible to use class names within range
+definitions.
+
+Typical use of the @code{class} request is to control line-breaking and
+hyphenation rules as defined by the @code{cflags} request.  For example,
+to inhibit line breaks before the characters belonging to the
+@code{prepunctx} class, you can write:
+
+@Example
+.cflags 2 \C'[prepunctx]'
+@endExample
+
+See the @code{cflags} request in @ref{Using Symbols}, for more details.
+@endDefreq
+
+@c ---------------------------------------------------------------------
+
+@node Special Fonts, Artificial Fonts, Character Classes, Fonts and Symbols
 @subsection Special Fonts
 @cindex special fonts
 @cindex fonts, special
diff --git a/man/groff.man b/man/groff.man
index c89dcfdd..8ec260c0 100644
--- a/man/groff.man
+++ b/man/groff.man
@@ -5,7 +5,7 @@ groff.man
 This file is part of groff, the GNU roff type-setting system.
 
 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
-              2009
+              2009, 2010
   Free Software Foundation, Inc.
 written by Bernd Warken <bwarken@mayn.de>
 maintained by Werner Lemberg <wl@gnu.org>
@@ -1312,6 +1312,15 @@ Chop the last character off macro, string, or diversion
 .IR object .
 .
 .TPx
+.REQ .class "name c1 c2 .\|.\|.\&"
+Assign a set of characters, character ranges, or classes
+.IR c1 ,
+.IR c2 ,
+.I .\|.\|.\&
+to
+.IR name .
+.
+.TPx
 .REQ .close "stream"
 Close the
 .IR stream .
diff --git a/man/groff_diff.man b/man/groff_diff.man
index 115c6d26..e0d355ea 100644
--- a/man/groff_diff.man
+++ b/man/groff_diff.man
@@ -138,7 +138,7 @@ Interpolate string
 taking
 .IR arg1 ,
 .IR arg2 ,
-.I .\|.\|.\&
+.IR .\|.\|. ,
 as arguments.
 .
 .TP
@@ -965,10 +965,11 @@ This is the same as
 .BR \[rs]p .
 .
 .TP
-.BI .cflags\  n\ c1\ c2\|.\|.\|.\&
+.BI .cflags\  "n c1 c2 .\|.\|."
 Characters
 .IR c1 ,
-.IR c2 ,\|.\|.\|.\&
+.IR c2 ,
+.IR .\|.\|. ,
 have properties determined by
 .IR n ,
 which is ORed from the following:
@@ -1093,6 +1094,21 @@ This is useful for removing the newline from the end of diversions
 that are to be interpolated as strings.
 .
 .TP
+.BI .class\  "name c1 c2 .\|.\|."
+Assign
+.I name
+to a set of characters
+.IR c1 ,
+.IR c2 ,
+.IR .\|.\|. ,
+so that they can be referred to from other requests easily (currently
+.B .cflags
+only).
+Character ranges (indicated by an intermediate `-') and nested classes
+are possible also.
+This is useful to assign properties to a large set of characters.
+.
+.TP
 .BI .close\  stream
 Close the stream named
 .IR stream ;
@@ -1394,12 +1410,13 @@ request but before the list of fonts declared with
 .BR .special .
 .
 .TP
-.BI .fspecial\  f\ s1\ s2\|.\|.\|.\&
+.BI .fspecial\  "f s1 s2 .\|.\|."
 When the current font is\~\c
 .IR f ,
 fonts
 .IR s1 ,
-.IR s2 ,\|.\|.\|.\&
+.IR s2 ,
+.IR .\|.\|. ,
 are special, that is, they are searched for glyphs not in
 the current font.
 .
@@ -1470,7 +1487,7 @@ is missing,
 switch to the previous glyph color.
 .
 .TP
-.BI .hcode \ c1\ code1\ c2\ code2\|.\|.\|.\&
+.BI .hcode\  "c1 code1 c2 code2 .\|.\|."
 Set the hyphenation code of character
 .I c1
 to
@@ -1478,7 +1495,8 @@ to
 and that of
 .I c2
 to
-.IR code2 .
+.IR code2 ,
+and so on.
 A hyphenation code must be a single input character (not a special
 character) other than a digit or a space.
 .
@@ -1625,7 +1643,7 @@ except that the hyphenation patterns from
 are appended to the patterns already loaded in the current language.
 .
 .TP
-.BI .hpfcode\  a\ b\ c\ d\ .\|.\|.
+.BI .hpfcode\  "a b c d .\|.\|."
 After reading a hyphenation patterns file with the
 .B hpf
 or
@@ -1930,10 +1948,11 @@ and
 with a positive value which are applied after the line is output.
 .
 .TP
-.BI .rchar\  c1\ c2\|.\|.\|.\&
+.BI .rchar\  "c1 c2 .\|.\|."
 Remove the definitions of glyphs
 .IR c1 ,
-.IR c2 ,\|.\|.\|.
+.IR c2 ,
+.I .\|.\|.
 This undoes the effect of a
 .B char
 request.
@@ -1948,10 +1967,11 @@ from the macro one level higher.
 No effect otherwise.
 .
 .TP
-.BI .rfschar\  c1\ c2\|.\|.\|.\&
+.BI .rfschar\  "c1 c2 .\|.\|."
 Remove the font-specific definitions of glyphs
 .IR c1 ,
-.IR c2 ,\|.\|.\|.
+.IR c2 ,
+.I .\|.\|.
 This undoes the effect of a
 .B fschar
 request.
@@ -2039,7 +2059,7 @@ is missing, arguments are shifted by\~1.
 Shifting by negative amounts is currently undefined.
 .
 .TP
-.BI .sizes\  s1\ s2\|.\|.\|.\|sn\  [0]
+.BI .sizes\  s1\ s2\ .\|.\|.\ sn\  [0]
 This command is similar to the
 .B sizes
 command of a
@@ -2048,7 +2068,8 @@ file.
 .
 It sets the available font sizes for the current font to
 .IR s1 ,
-.IR s2 ,\|.\|.\|.\|,\~ sn
+.IR s2 ,
+.IR .\|.\|.\| ,\~ sn
 scaled points.
 .
 The list of sizes can be terminated by an optional\~\c
@@ -2063,10 +2084,11 @@ Contrary to the font file command, the list can't extend over more
 than a single line.
 .
 .TP
-.BI .special\  s1\ s2\|.\|.\|.\&
+.BI .special\  "s1 s2 .\|.\|."
 Fonts
 .IR s1 ,
-.IR s2 ,\|.\|.\|.\&
+.IR s2 ,
+.IR .\|.\|. ,
 are special and are searched for glyphs not in the current
 font.
 .
@@ -2563,18 +2585,21 @@ In GNU troff, as in UNIX troff, you should always follow a sentence
 with either a newline or two spaces.
 .
 .TP
-.BI .ta\  n1\ n2\|.\|.\|.nn \ T\  r1\ r2\|.\|.\|.\|rn
+.BI .ta\  "n1 n2 .\|.\|. nn " "T " "r1 r2 .\|.\|. rn"
 Set tabs at positions
 .IR n1 ,
-.IR n2 ,\|.\|.\|.\|,
+.IR n2 ,
+.IR .\|.\|. ,
 .I nn
 and then set tabs at
 .IR nn \|+\| r1 ,
-.IR nn \|+\| r2 ,\|.\|.\|.\|,
+.IR nn \|+\| r2 ,
+.IR .\|.\|. ,
 .IR nn \|+\| rn
 and then at
 .IR nn \|+\| rn \|+\| r1 ,
-.IR nn \|+\| rn \|+\| r2 ,\|.\|.\|.\|,
+.IR nn \|+\| rn \|+\| r2 ,
+.IR .\|.\|. ,
 .IR nn \|+\| rn \|+\| rn ,
 and so on.
 For example,
diff --git a/src/include/font.h b/src/include/font.h
index 944250b9..75d2ef16 100644
--- a/src/include/font.h
+++ b/src/include/font.h
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-/* Copyright (C) 1989, 1990, 1991, 1992, 2002, 2004, 2006, 2009
+/* Copyright (C) 1989, 1990, 1991, 1992, 2002, 2004, 2006, 2009, 2010
    Free Software Foundation, Inc.
      Written by James Clark (jjc@jclark.com)
 
@@ -73,6 +73,9 @@ inline int glyph_to_number(glyph *);	// Convert the given glyph back to
 			// a numbered character.
 inline int glyph_to_index(glyph *);	// Return the unique index that is
 			// associated with the given glyph. It is >= 0.
+extern int glyph_to_unicode(glyph *);	// Convert the given glyph to its
+			// Unicode codepoint.  Return -1 if it does not
+			// designate a Unicode character.
 
 inline int glyph_to_number(glyph *g)
 {
diff --git a/src/libs/libgroff/font.cpp b/src/libs/libgroff/font.cpp
index d0b4a12e..8dff71e7 100644
--- a/src/libs/libgroff/font.cpp
+++ b/src/libs/libgroff/font.cpp
@@ -1,6 +1,6 @@
 // -*- C++ -*-
 /* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2001, 2002, 2003, 2004, 2005,
-                 2006, 2008, 2009
+                 2006, 2008, 2009, 2010
    Free Software Foundation, Inc.
      Written by James Clark (jjc@jclark.com)
 
@@ -147,6 +147,47 @@ void text_file::error(const char *format,
     error_with_file_and_line(path, lineno, format, arg1, arg2, arg3);
 }
 
+int glyph_to_unicode(glyph *g)
+{
+  const char *nm = glyph_to_name(g);
+  if (nm != NULL) {
+    // ASCII character?
+    if (nm[0] == 'c' && nm[1] == 'h' && nm[2] == 'a' && nm[3] == 'r'
+	&& (nm[4] >= '0' && nm[4] <= '9')) {
+      int n = (nm[4] - '0');
+      if (nm[5] == '\0')
+	return n;
+      if (n > 0 && (nm[5] >= '0' && nm[5] <= '9')) {
+	n = 10*n + (nm[5] - '0');
+	if (nm[6] == '\0')
+	  return n;
+	if (nm[6] >= '0' && nm[6] <= '9') {
+	  n = 10*n + (nm[6] - '0');
+	  if (nm[7] == '\0' && n < 128)
+	    return n;
+	}
+      }
+    }
+    // Unicode character?
+    if (check_unicode_name(nm)) {
+      char *ignore;
+      return (int)strtol(nm + 1, &ignore, 16);
+    }
+    // If `nm' is a single letter `x', the glyph name is `\x'.
+    char buf[] = { '\\', '\0', '\0' };
+    if (nm[1] == '\0') {
+      buf[1] = nm[0];
+      nm = buf;
+    }
+    // groff glyphs that map to Unicode?
+    const char *unicode = glyph_name_to_unicode(nm);
+    if (unicode != NULL && strchr(unicode, '_') == NULL) {
+      char *ignore;
+      return (int)strtol(unicode, &ignore, 16);
+    }
+  }
+  return -1;
+}
 
 /* font functions */
 
@@ -269,42 +310,11 @@ int font::contains(glyph *g)
     return 1;
   if (is_unicode) {
     // Unicode font
-    const char *nm = glyph_to_name(g);
-    if (nm != NULL) {
-      // ASCII character?
-      if (nm[0] == 'c' && nm[1] == 'h' && nm[2] == 'a' && nm[3] == 'r'
-          && (nm[4] >= '0' && nm[4] <= '9')) {
-	int n = (nm[4] - '0');
-	if (nm[5] == '\0')
-	  return 1;
-	if (n > 0 && (nm[5] >= '0' && nm[5] <= '9')) {
-	  n = 10*n + (nm[5] - '0');
-	  if (nm[6] == '\0')
-	    return 1;
-	  if (nm[6] >= '0' && nm[6] <= '9') {
-	    n = 10*n + (nm[6] - '0');
-	    if (nm[7] == '\0' && n < 128)
-	      return 1;
-	  }
-	}
-      }
-      // Unicode character?
-      if (check_unicode_name(nm))
-	return 1;
-      // If `nm' is a single letter `x', the glyph name is `\x'.
-      char buf[] = { '\\', '\0', '\0' };
-      if (nm[1] == '\0') {
-	buf[1] = nm[0];
-        nm = buf;
-      }
-      // groff glyph name that maps to Unicode?
-      const char *unicode = glyph_name_to_unicode(nm);
-      if (unicode != NULL && strchr(unicode, '_') == NULL)
-	return 1;
-    }
+    // ASCII or Unicode character, or groff glyph name that maps to Unicode?
+    if (glyph_to_unicode(g) >= 0)
+      return 1;
     // Numbered character?
-    int n = glyph_to_number(g);
-    if (n >= 0)
+    if (glyph_to_number(g) >= 0)
       return 1;
   }
   return 0;
@@ -554,43 +564,10 @@ int font::get_code(glyph *g)
   }
   if (is_unicode) {
     // Unicode font
-    const char *nm = glyph_to_name(g);
-    if (nm != NULL) {
-      // ASCII character?
-      if (nm[0] == 'c' && nm[1] == 'h' && nm[2] == 'a' && nm[3] == 'r'
-          && (nm[4] >= '0' && nm[4] <= '9')) {
-	int n = (nm[4] - '0');
-	if (nm[5] == '\0')
-	  return n;
-	if (n > 0 && (nm[5] >= '0' && nm[5] <= '9')) {
-	  n = 10*n + (nm[5] - '0');
-	  if (nm[6] == '\0')
-	    return n;
-	  if (nm[6] >= '0' && nm[6] <= '9') {
-	    n = 10*n + (nm[6] - '0');
-	    if (nm[7] == '\0' && n < 128)
-	      return n;
-	  }
-	}
-      }
-      // Unicode character?
-      if (check_unicode_name(nm)) {
-	char *ignore;
-	return (int)strtol(nm + 1, &ignore, 16);
-      }
-      // If `nm' is a single letter `x', the glyph name is `\x'.
-      char buf[] = { '\\', '\0', '\0' };
-      if (nm[1] == '\0') {
-	buf[1] = nm[0];
-        nm = buf;
-      }
-      // groff glyphs that map to Unicode?
-      const char *unicode = glyph_name_to_unicode(nm);
-      if (unicode != NULL && strchr(unicode, '_') == NULL) {
-	char *ignore;
-	return (int)strtol(unicode, &ignore, 16);
-      }
-    }
+    // ASCII or Unicode character, or groff glyph name that maps to Unicode?
+    int uni = glyph_to_unicode(g);
+    if (uni >= 0)
+      return uni;
     // Numbered character?
     int n = glyph_to_number(g);
     if (n >= 0)
diff --git a/src/roff/troff/charinfo.h b/src/roff/troff/charinfo.h
index 2c2c2685..c71383ed 100644
--- a/src/roff/troff/charinfo.h
+++ b/src/roff/troff/charinfo.h
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-/* Copyright (C) 1989, 1990, 1991, 1992, 2001, 2002, 2006, 2009
+/* Copyright (C) 1989, 1990, 1991, 1992, 2001, 2002, 2006, 2009, 2010
    Free Software Foundation, Inc.
      Written by James Clark (jjc@jclark.com)
 
@@ -18,6 +18,9 @@ for more details.
 You should have received a copy of the GNU General Public License
 along with this program. If not, see <http://www.gnu.org/licenses/>. */
 
+#include <vector>
+#include <utility>
+
 class macro;
 
 class charinfo : glyph {
@@ -35,6 +38,9 @@ class charinfo : glyph {
   char translate_input;		// non-zero means that asciify_code is
 				// active for .asciify (set by .trin)
   char_mode mode;
+  // Unicode character classes
+  std::vector<std::pair<int, int> > ranges;
+  std::vector<charinfo *> nested_classes;
 public:
   enum {		// Values for the flags bitmask.  See groff
 			// manual, description of the `.cflags' request.
@@ -66,6 +72,7 @@ public:
   unsigned char get_hyphenation_code();
   unsigned char get_ascii_code();
   unsigned char get_asciify_code();
+  int get_unicode_code();
   void set_hyphenation_code(unsigned char);
   void set_ascii_code(unsigned char);
   void set_asciify_code(unsigned char);
@@ -73,6 +80,7 @@ public:
   int get_translation_input();
   charinfo *get_translation(int = 0);
   void set_translation(charinfo *, int, int);
+  unsigned char get_flags();
   void set_flags(unsigned char);
   void set_special_translation(int, int);
   int get_special_translation(int = 0);
@@ -87,6 +95,13 @@ public:
   int is_fallback();
   int is_special();
   symbol *get_symbol();
+  void add_to_class(int);
+  void add_to_class(int, int);
+  void add_to_class(charinfo *);
+  bool is_class();
+  bool contains(int);
+  bool contains(symbol);
+  bool contains(charinfo *);
 };
 
 charinfo *get_charinfo(symbol);
@@ -95,37 +110,37 @@ charinfo *get_charinfo_by_number(int);
 
 inline int charinfo::overlaps_horizontally()
 {
-  return flags & OVERLAPS_HORIZONTALLY;
+  return get_flags() & OVERLAPS_HORIZONTALLY;
 }
 
 inline int charinfo::overlaps_vertically()
 {
-  return flags & OVERLAPS_VERTICALLY;
+  return get_flags() & OVERLAPS_VERTICALLY;
 }
 
 inline int charinfo::can_break_before()
 {
-  return flags & BREAK_BEFORE;
+  return get_flags() & BREAK_BEFORE;
 }
 
 inline int charinfo::can_break_after()
 {
-  return flags & BREAK_AFTER;
+  return get_flags() & BREAK_AFTER;
 }
 
 inline int charinfo::ends_sentence()
 {
-  return flags & ENDS_SENTENCE;
+  return get_flags() & ENDS_SENTENCE;
 }
 
 inline int charinfo::transparent()
 {
-  return flags & TRANSPARENT;
+  return get_flags() & TRANSPARENT;
 }
 
 inline int charinfo::ignore_hcodes()
 {
-  return flags & IGNORE_HCODES;
+  return get_flags() & IGNORE_HCODES;
 }
 
 inline int charinfo::numbered()
@@ -214,5 +229,27 @@ inline int charinfo::first_time_not_found()
 
 inline symbol *charinfo::get_symbol()
 {
-  return( &nm );
+  return &nm;
+}
+
+inline void charinfo::add_to_class(int c)
+{
+  // TODO ranges cumbersome for single characters?
+  ranges.push_back(std::pair<int, int>(c, c));
+}
+
+inline void charinfo::add_to_class(int lo,
+				   int hi)
+{
+  ranges.push_back(std::pair<int, int>(lo, hi));
+}
+
+inline void charinfo::add_to_class(charinfo *ci)
+{
+  nested_classes.push_back(ci);
+}
+
+inline bool charinfo::is_class()
+{
+  return (!ranges.empty() || !nested_classes.empty());
 }
diff --git a/src/roff/troff/input.cpp b/src/roff/troff/input.cpp
index 5335c1ce..cdb82fe2 100644
--- a/src/roff/troff/input.cpp
+++ b/src/roff/troff/input.cpp
@@ -1,6 +1,6 @@
 // -*- C++ -*-
 /* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2001, 2002, 2003, 2004, 2005,
-                 2006, 2007, 2008, 2009
+                 2006, 2007, 2008, 2009, 2010
    Free Software Foundation, Inc.
      Written by James Clark (jjc@jclark.com)
 
@@ -6740,6 +6740,102 @@ void hyphenation_patterns_file_code()
   skip_line();
 }
 
+dictionary char_class_dictionary(501);
+
+void define_class()
+{
+  tok.skip();
+  symbol nm = get_name(1);
+  if (nm.is_null()) {
+    skip_line();
+    return;
+  }
+  charinfo *ci = get_charinfo(nm);
+  charinfo *child1 = 0, *child2 = 0;
+  while (!tok.newline() && !tok.eof()) {
+    tok.skip();
+    if (child1 != 0 && tok.ch() == '-') {
+      tok.next();
+      child2 = tok.get_char(1);
+      if (!child2) {
+	warning(WARN_MISSING,
+		"missing end of character range in class `%1'",
+		nm.contents());
+	skip_line();
+	return;
+      }
+      if (child1->is_class() || child2->is_class()) {
+	warning(WARN_SYNTAX,
+		"nested character class is not allowed in range definition");
+	skip_line();
+	return;
+      }
+      int u1 = child1->get_unicode_code();
+      int u2 = child2->get_unicode_code();
+      if (u1 < 0) {
+	warning(WARN_SYNTAX,
+		"invalid start value in character range");
+	skip_line();
+	return;
+      }
+      if (u2 < 0) {
+	warning(WARN_SYNTAX,
+		"invalid end value in character range");
+	skip_line();
+	return;
+      }
+      ci->add_to_class(u1, u2);
+      child1 = child2 = 0;
+    }
+    else if (child1 != 0) {
+      if (child1->is_class())
+	ci->add_to_class(child1);
+      else {
+	int u1 = child1->get_unicode_code();
+	if (u1 < 0) {
+	  warning(WARN_SYNTAX,
+		  "invalid character value in class `%1'",
+		  nm.contents());
+	  skip_line();
+	  return;
+	}
+	ci->add_to_class(u1);
+      }
+      child1 = 0;
+    }
+    child1 = tok.get_char(1);
+    tok.next();
+    if (!child1) {
+      if (!tok.newline())
+	skip_line();
+      break;
+    }
+  }
+  if (child1 != 0) {
+    if (child1->is_class())
+      ci->add_to_class(child1);
+    else {
+      int u1 = child1->get_unicode_code();
+      if (u1 < 0) {
+	warning(WARN_SYNTAX,
+		"invalid character value in class `%1'",
+		nm.contents());
+	skip_line();
+	return;
+      }
+      ci->add_to_class(u1);
+    }
+    child1 = 0;
+  }
+  if (!ci->is_class()) {
+    warning(WARN_SYNTAX,
+	    "empty class definition for `%1'",
+	    nm.contents());
+    return;
+  }
+  (void)char_class_dictionary.lookup(nm, ci);
+}
+
 charinfo *token::get_char(int required)
 {
   if (type == TOKEN_CHAR)
@@ -7817,6 +7913,7 @@ void init_input_requests()
   init_request("cflags", char_flags);
   init_request("char", define_character);
   init_request("chop", chop_macro);
+  init_request("class", define_class);
   init_request("close", close_request);
   init_request("color", activate_color);
   init_request("composite", composite_request);
@@ -8367,6 +8464,13 @@ charinfo::charinfo(symbol s)
   number = -1;
 }
 
+int charinfo::get_unicode_code()
+{
+  if (ascii_code != '\0')
+    return ascii_code;
+  return glyph_to_unicode(this);
+}
+
 void charinfo::set_hyphenation_code(unsigned char c)
 {
   hyphenation_code = c;
@@ -8388,6 +8492,27 @@ void charinfo::set_translation(charinfo *ci, int tt, int ti)
   transparent_translate = tt;
 }
 
+// Get the union of all flags affecting this charinfo.
+unsigned char charinfo::get_flags()
+{
+  unsigned char all_flags = flags;
+  dictionary_iterator iter(char_class_dictionary);
+  charinfo *cp;
+  symbol s;
+  while (iter.get(&s, (void **)&cp)) {
+    assert(!s.is_null());
+    if (cp->contains(get_unicode_code())) {
+#if defined(DEBUGGING)
+      if (debug_state)
+	fprintf(stderr, "charinfo::get_flags %p %s %d\n",
+			(void *)cp, cp->nm.contents(), cp->flags);
+#endif
+      all_flags |= cp->flags;
+    }
+  }
+  return all_flags;
+}
+
 void charinfo::set_special_translation(int c, int tt)
 {
   special_translation = c;
@@ -8432,6 +8557,50 @@ int charinfo::get_number()
   return number;
 }
 
+bool charinfo::contains(int c)
+{
+  std::vector<std::pair<int, int> >::const_iterator ranges_iter;
+  ranges_iter = ranges.begin();
+  while (ranges_iter != ranges.end()) {
+    if (c >= ranges_iter->first && c <= ranges_iter->second) {
+#if defined(DEBUGGING)
+      if (debug_state)
+	fprintf(stderr, "charinfo::contains(%d)\n", c);
+#endif
+      return true;
+    }
+    ++ranges_iter;
+  }
+
+  std::vector<charinfo *>::const_iterator nested_iter;
+  nested_iter = nested_classes.begin();
+  while (nested_iter != nested_classes.end()) {
+    if ((*nested_iter)->contains(c))
+      return true;
+    ++nested_iter;
+  }
+
+  return false;
+}
+
+bool charinfo::contains(symbol s)
+{
+  const char *unicode = glyph_name_to_unicode(s.contents());
+  if (unicode != NULL && strchr(unicode, '_') == NULL) {
+    char *ignore;
+    int c = (int)strtol(unicode, &ignore, 16);
+    return contains(c);
+  }
+  else
+    return false;
+}
+
+bool charinfo::contains(charinfo *)
+{
+  // TODO
+  return false;
+}
+
 symbol UNNAMED_SYMBOL("---");
 
 // For numbered characters not between 0 and 255, we make a symbol out