[regexp] implement character classes for unicode regexps.

src/ostreams.cc

Index: src/ostreams.cc
diff --git a/src/ostreams.cc b/src/ostreams.cc
index a7a67f5d2f06002fc9899b7c391476fd16022932..1652d4f6d57086884767a98101f7cbfdb7b5305d 100644
--- a/src/ostreams.cc
+++ b/src/ostreams.cc
@@ -60,6 +60,14 @@ std::ostream& PrintUC16(std::ostream& os, uint16_t c, bool (*pred)(uint16_t)) {
   return os << buf;
 }
 
+
+std::ostream& PrintUC32(std::ostream& os, int32_t c, bool (*pred)(uint16_t)) {
+  if (c <= 0xffff) return PrintUC16(os, static_cast<uint16_t>(c), pred);

[erikcorry, 2016/01/20 10:47:05]

kMaxUtf16CodeUnit

[Yang, 2016/01/20 13:06:20]

Done.

+  char buf[12];

[erikcorry, 2016/01/20 10:47:05]

Perhaps 13 so that if c.value is somehow a maximal 32 bit value outside the
Unicode range we still have space for the final }

[Yang, 2016/01/20 13:06:20]

Done.

+  snprintf(buf, sizeof(buf), "\\u{%06x}", c);
+  return os << buf;
+}
+
 }  // namespace
 
 
@@ -81,5 +89,10 @@ std::ostream& operator<<(std::ostream& os, const AsUC16& c) {
   return PrintUC16(os, c.value, IsPrint);
 }
 
+
+std::ostream& operator<<(std::ostream& os, const AsUC32& c) {
+  return PrintUC32(os, c.value, IsPrint);
+}
+
 }  // namespace internal
 }  // namespace v8