diff --git a/include/cppjieba/SegmentBase.hpp b/include/cppjieba/SegmentBase.hpp
index 8630cfd..9ce21c4 100644
--- a/include/cppjieba/SegmentBase.hpp
+++ b/include/cppjieba/SegmentBase.hpp
@@ -8,27 +8,50 @@
 
 namespace cppjieba {
 
-//const char* const SPECIAL_CHARS = " \t\n，。";
-const Rune SPECIAL_SYMBOL[] = {32u, 9u, 10u, 65292u, 12290u};
+const char* const SPECIAL_RUNES = " \t\n，。";
 
 using namespace limonp;
 
 class SegmentBase {
  public:
   SegmentBase() {
-    LoadSpecialSymbols();
+    XCHECK(Insert(SPECIAL_RUNES));
   }
   ~SegmentBase() {
   }
 
  protected:
-  void LoadSpecialSymbols() {
-    size_t size = sizeof(SPECIAL_SYMBOL)/sizeof(*SPECIAL_SYMBOL);
-    for (size_t i = 0; i < size; i ++) {
-      symbols_.insert(SPECIAL_SYMBOL[i]);
+  bool Insert(const string& s) {
+    RuneStrArray runes;
+    if (!DecodeRunesInString(s, runes)) {
+      XLOG(ERROR) << "decode " << s << " failed";
+      return false;
     }
-    assert(symbols_.size());
+    for (size_t i = 0; i < runes.size(); i++) {
+      if (!symbols_.insert(runes[i].rune).second) {
+        XLOG(ERROR) << s.substr(runes[i].offset, runes[i].len) << " already exists";
+        return false;
+      }
+    }
+    return true;
   }
+  //bool Remove(const string& s) {
+  //  RuneStrArray runes;
+  //  if (!DecodeRunesInString(s, runes)) {
+  //    XLOG(ERROR) << "decode " << s << " failed";
+  //    return false;
+  //  }
+  //  for (size_t i = 0; i < runes.size(); i++) {
+  //    unordered_set<Rune>::iterator iter = symbols_.find(runes[i].rune);
+  //    if (iter == symbols_.end()) {
+  //      XLOG(ERROR) << s.substr(runes[i].offset, runes[i].len) << " not found";
+  //      return false;
+  //    }
+  //    symbols_.erase(iter);
+  //  }
+  //  return true;
+  //}
+
   unordered_set<Rune> symbols_;
 }; // class SegmentBase