Improve [:alpha:] and [:alnum:] for multibyte characters (Bug#19878)

 src/character.c (alphabeticp, decimalnump): New functions.
 src/character.h (alphabeticp, decimalnump): Add prototypes.
 src/regex.c (ISALNUM, ISALPHA): Check Unicode character properties
 for multibyte characters by calling alphabeticp and decimalnump.
 (BIT_ALPHA, BIT_ALNUM): New bit masks.
 (re_wctype_to_bit): Return them when the class is RECC_ALPHA or
 RECC_ALNUM.
 (re_match_2_internal): Call ISALPHA and ISALNUM when appropriate.

 doc/lispref/searching.texi (Char Classes): Update the documentation of
 [:alpha:] and [:alnum:].

 etc/NEWS: Mention the changes in [:alpha:] and [:alnum:].

4 files changed, 70 insertions, 6 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index df687914911..97ecbac0953 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2015-02-28  Eli Zaretskii  <eliz@gnu.org>
+
+        * character.c (alphabeticp, decimalnump): New functions.
+        * character.h (alphabeticp, decimalnump): Add prototypes.
+
+        * regex.c (ISALNUM, ISALPHA): Check Unicode character properties
+        for multibyte characters by calling alphabeticp and decimalnump.
+        (BIT_ALPHA, BIT_ALNUM): New bit masks.
+        (re_wctype_to_bit): Return them when the class is RECC_ALPHA or
+        RECC_ALNUM.
+        (re_match_2_internal): Call ISALPHA and ISALNUM when appropriate.
+        (Bug#19878)
+
 2015-02-27  Jan Djärv  <jan.h.d@swipnet.se>
 
         * xterm.h (x_real_pos_and_offsets): Take outer_border as arg also.
diff --git a/src/character.c b/src/character.c
index 39d32c9d41a..999f99aa003 100644
--- a/src/character.c
+++ b/src/character.c
@@ -984,6 +984,48 @@ character is not ASCII nor 8-bit character, an error is signaled.  */)
 
 #ifdef emacs
 
+/* Return 'true' if C is an alphabetic character as defined by its
+   Unicode properties.  */
+bool
+alphabeticp (int c)
+{
+  Lisp_Object category = CHAR_TABLE_REF (Vunicode_category_table, c);
+
+  if (INTEGERP (category))
+    {
+      unicode_category_t gen_cat = XINT (category);
+
+      /* See UTS #18.  There are additional characters that should be
+         here, those designated as Other_uppercase, Other_lowercase,
+         and Other_alphabetic; FIXME.  */
+      return (gen_cat == UNICODE_CATEGORY_Lu
+              || gen_cat == UNICODE_CATEGORY_Ll
+              || gen_cat == UNICODE_CATEGORY_Lt
+              || gen_cat == UNICODE_CATEGORY_Lm
+              || gen_cat == UNICODE_CATEGORY_Lo
+              || gen_cat == UNICODE_CATEGORY_Mn
+              || gen_cat == UNICODE_CATEGORY_Mc
+              || gen_cat == UNICODE_CATEGORY_Me
+              || gen_cat == UNICODE_CATEGORY_Nl) ? true : false;
+    }
+}
+
+/* Return 'true' if C is an decimal-number character as defined by its
+   Unicode properties.  */
+bool
+decimalnump (int c)
+{
+  Lisp_Object category = CHAR_TABLE_REF (Vunicode_category_table, c);
+
+  if (INTEGERP (category))
+    {
+      unicode_category_t gen_cat = XINT (category);
+
+      /* See UTS #18.  */
+      return (gen_cat == UNICODE_CATEGORY_Nd) ? true : false;
+    }
+}
+
 void
 syms_of_character (void)
 {
diff --git a/src/character.h b/src/character.h
index 5043880cb42..7d902952db6 100644
--- a/src/character.h
+++ b/src/character.h
@@ -660,6 +660,9 @@ extern ptrdiff_t lisp_string_width (Lisp_Object, ptrdiff_t,
 extern Lisp_Object Vchar_unify_table;
 extern Lisp_Object string_escape_byte8 (Lisp_Object);
 
+extern bool alphabeticp (int);
+extern bool decimalnump (int);
+
 /* Return a translation table of id number ID.  */
 #define GET_TRANSLATION_TABLE(id) \
   (XCDR (XVECTOR (Vtranslation_table_vector)->contents[(id)]))
diff --git a/src/regex.c b/src/regex.c
index 41fe3fa8088..1afc5037594 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -324,12 +324,12 @@ enum syntaxcode { Swhitespace = 0, Sword = 1, Ssymbol = 2 };
                     ? (((c) >= 'a' && (c) <= 'z')       \
                        || ((c) >= 'A' && (c) <= 'Z')    \
                        || ((c) >= '0' && (c) <= '9'))   \
-                    : SYNTAX (c) == Sword)
+                    : (alphabeticp (c) || decimalnump (c)))
 
 # define ISALPHA(c) (IS_REAL_ASCII (c)                  \
                     ? (((c) >= 'a' && (c) <= 'z')       \
                        || ((c) >= 'A' && (c) <= 'Z'))   \
-                    : SYNTAX (c) == Sword)
+                    : alphabeticp (c))
 
 # define ISLOWER(c) lowercasep (c)
 
@@ -1872,6 +1872,8 @@ struct range_table_work_area
 #define BIT_SPACE       0x8
 #define BIT_UPPER       0x10
 #define BIT_MULTIBYTE   0x20
+#define BIT_ALPHA       0x40
+#define BIT_ALNUM       0x80
 
 
 /* Set the bit for character C in a list.  */
@@ -2072,7 +2074,9 @@ re_wctype_to_bit (re_wctype_t cc)
     {
     case RECC_NONASCII: case RECC_PRINT: case RECC_GRAPH:
     case RECC_MULTIBYTE: return BIT_MULTIBYTE;
-    case RECC_ALPHA: case RECC_ALNUM: case RECC_WORD: return BIT_WORD;
+    case RECC_ALPHA: return BIT_ALPHA;
+    case RECC_ALNUM: return BIT_ALNUM;
+    case RECC_WORD: return BIT_WORD;
     case RECC_LOWER: return BIT_LOWER;
     case RECC_UPPER: return BIT_UPPER;
     case RECC_PUNCT: return BIT_PUNCT;
@@ -2930,7 +2934,7 @@ regex_compile (const_re_char *pattern, size_t size, reg_syntax_t syntax,
 #endif  /* emacs */
                         /* In most cases the matching rule for char classes
                            only uses the syntax table for multibyte chars,
-                           so that the content of the syntax-table it is not
+                           so that the content of the syntax-table is not
                            hardcoded in the range_table.  SPACE and WORD are
                            the two exceptions.  */
                         if ((1 << cc) & ((1 << RECC_SPACE) | (1 << RECC_WORD)))
@@ -2945,7 +2949,7 @@ regex_compile (const_re_char *pattern, size_t size, reg_syntax_t syntax,
                         p = class_beg;
                         SET_LIST_BIT ('[');
 
-                        /* Because the `:' may starts the range, we
+                        /* Because the `:' may start the range, we
                            can't simply set bit and repeat the loop.
                            Instead, just set it to C and handle below.  */
                         c = ':';
@@ -5513,7 +5517,9 @@ re_match_2_internal (struct re_pattern_buffer *bufp, const_re_char *string1,
                     | (class_bits & BIT_PUNCT && ISPUNCT (c))
                     | (class_bits & BIT_SPACE && ISSPACE (c))
                     | (class_bits & BIT_UPPER && ISUPPER (c))
-                    | (class_bits & BIT_WORD  && ISWORD (c)))
+                    | (class_bits & BIT_WORD  && ISWORD  (c))
+                    | (class_bits & BIT_ALPHA && ISALPHA (c))
+                    | (class_bits & BIT_ALNUM && ISALNUM (c)))
                   not = !not;
                 else
                   CHARSET_LOOKUP_RANGE_TABLE_RAW (not, c, range_table, count);