[regexp] extend property classes by unicode blocks.

src/regexp/regexp-parser.cc

Index: src/regexp/regexp-parser.cc
diff --git a/src/regexp/regexp-parser.cc b/src/regexp/regexp-parser.cc
index 21992e42a64ee337a5448444f30e6f9cb050bf44..cfbdb6b3e416f7f06ef01bb29bb2bec8768b96b8 100644
--- a/src/regexp/regexp-parser.cc
+++ b/src/regexp/regexp-parser.cc
@@ -836,60 +836,79 @@ bool RegExpParser::ParseUnicodeEscape(uc32* value) {
   return result;
 }
 
+ZoneList<CharacterRange>* LookupPropertyClass(UProperty property,
+                                              const char* property_name,
+                                              Zone* zone) {
+  int32_t property_value = u_getPropertyValueEnum(property, property_name);
+  if (property_value == UCHAR_INVALID_CODE) return nullptr;
+
+  USet* set = uset_openEmpty();
+  UErrorCode ec = U_ZERO_ERROR;
+  uset_applyIntPropertyValue(set, property, property_value, &ec);
+  ZoneList<CharacterRange>* ranges = nullptr;
+  if (ec == U_ZERO_ERROR && !uset_isEmpty(set)) {
+    uset_removeAllStrings(set);
+    int item_count = uset_getItemCount(set);
+    ranges = new (zone) ZoneList<CharacterRange>(item_count, zone);
+    int item_result = 0;
+    for (int i = 0; i < item_count; i++) {
+      uc32 start = 0;
+      uc32 end = 0;
+      item_result += uset_getItem(set, i, &start, &end, nullptr, 0, &ec);
+      ranges->Add(CharacterRange::Range(start, end), zone);
+    }
+    DCHECK_EQ(U_ZERO_ERROR, ec);
+    DCHECK_EQ(0, item_result);
+  }
+  uset_close(set);
+  return ranges;
+}
+
 ZoneList<CharacterRange>* RegExpParser::ParsePropertyClass() {
 #ifdef V8_I18N_SUPPORT
-  ZoneList<char> property_name(0, zone());
+  List<char> property_name_list(0);
   if (current() == '{') {
     for (Advance(); current() != '}'; Advance()) {
       if (!has_next()) return nullptr;
-      property_name.Add(static_cast<char>(current()), zone());
+      property_name_list.Add(static_cast<char>(current()));
     }
   } else if (current() != kEndMarker) {
-    property_name.Add(static_cast<char>(current()), zone());
+    property_name_list.Add(static_cast<char>(current()));
   } else {
     return nullptr;
   }
   Advance();
-  property_name.Add(0, zone());  // null-terminate string.
+  property_name_list.Add(0);  // null-terminate string.
+
+  const char* property_name = property_name_list.ToConstVector().start();
+
+  ZoneList<CharacterRange>* ranges = nullptr;
+
+#define PROPERTY_NAME_LOOKUP(PROPERTY)                             \
+  do {                                                             \
+    ranges = LookupPropertyClass(PROPERTY, property_name, zone()); \
+    if (ranges != nullptr) return ranges;                          \
+  } while (false)
 
   // Property names are defined in unicode database files. For aliases of
   // these property names, see PropertyValueAliases.txt.
-  UProperty kPropertyClasses[] = {
-      // General_Category (gc) found in PropertyValueAliases.txt
-      UCHAR_GENERAL_CATEGORY_MASK,
-      // Script (sc) found in Scripts.txt
-      UCHAR_SCRIPT,
-  };
-
-  for (int i = 0; i < arraysize(kPropertyClasses); i++) {
-    UProperty property_class = kPropertyClasses[i];
-    int32_t category = u_getPropertyValueEnum(
-        property_class, property_name.ToConstVector().start());
-    if (category == UCHAR_INVALID_CODE) continue;
-
-    USet* set = uset_openEmpty();
-    UErrorCode ec = U_ZERO_ERROR;
-    uset_applyIntPropertyValue(set, property_class, category, &ec);
-    ZoneList<CharacterRange>* ranges = nullptr;
-    if (ec == U_ZERO_ERROR && !uset_isEmpty(set)) {
-      uset_removeAllStrings(set);
-      int item_count = uset_getItemCount(set);
-      ranges = new (zone()) ZoneList<CharacterRange>(item_count, zone());
-      int item_result = 0;
-      for (int i = 0; i < item_count; i++) {
-        uc32 start = 0;
-        uc32 end = 0;
-        item_result += uset_getItem(set, i, &start, &end, nullptr, 0, &ec);
-        ranges->Add(CharacterRange::Range(start, end), zone());
-      }
-      DCHECK_EQ(U_ZERO_ERROR, ec);
-      DCHECK_EQ(0, item_result);
-    }
-    uset_close(set);
-    return ranges;
+  // General_Category (gc) found in PropertyValueAliases.txt
+  PROPERTY_NAME_LOOKUP(UCHAR_GENERAL_CATEGORY_MASK);
+  // Script (sc) found in Scripts.txt
+  PROPERTY_NAME_LOOKUP(UCHAR_SCRIPT);
+  // Block (blk) found in Blocks.txt
+  PROPERTY_NAME_LOOKUP(UCHAR_BLOCK);
+  // For disambiguation, script names may have an "Is"-prefix and block names
+  // may have an "In"-prefix. This convention is up for debate and for the spec
+  // to settle.

[Dan Ehrenberg, 2016/03/10 18:43:20]

I don't like this mechanism, of letting them overlap and then also allowing
disambiguation! If there's a block by a particular name in one Unicode version,
and then a script is added later by the same name, then you'll get different
results. I think Brian Terlson proposed making "In" for blocks mandatory and not
exist ever for scripts. What if we either did that, or Is/In mandatory?

+  if (property_name_list.length() > 3 && property_name[0] == 'I') {
+    char second_char = property_name[1];
+    property_name += 2;
+    if (second_char == 's') PROPERTY_NAME_LOOKUP(UCHAR_SCRIPT);
+    if (second_char == 'n') PROPERTY_NAME_LOOKUP(UCHAR_BLOCK);
   }
+#undef PROPERTY_NAME_LOOKUP
 #endif  // V8_I18N_SUPPORT
-
   return nullptr;
 }