class Jieba: support default dictpath

include/cppjieba/Jieba.hpp

@@ -8,19 +8,24 @@ namespace cppjieba {
 
 class Jieba {
  public:
-  Jieba(const string& dict_path, 
-        const string& model_path,
-        const string& user_dict_path, 
-        const string& idfPath, 
-        const string& stopWordPath) 
-    : dict_trie_(dict_path, user_dict_path),
-      model_(model_path),
+  Jieba(const string& dict_path = "", 
+        const string& model_path = "",
+        const string& user_dict_path = "", 
+        const string& idf_path = "", 
+        const string& stop_word_path = "") 
+    : dict_trie_(getPath(dict_path, "jieba.dict.utf8")),
+      model_(getPath(model_path, "hmm_model.utf8")),
       mp_seg_(&dict_trie_),
       hmm_seg_(&model_),
       mix_seg_(&dict_trie_, &model_),
       full_seg_(&dict_trie_),
       query_seg_(&dict_trie_, &model_),
-      extractor(&dict_trie_, &model_, idfPath, stopWordPath) {
+      extractor(&dict_trie_, &model_, 
+                getPath(idf_path, "idf.utf8"), 
+                getPath(stop_word_path, "stop_words.utf8")) {
+    if (!user_dict_path.empty()) {
+      dict_trie_.LoadUserDict(user_dict_path);
+    }
   }
   ~Jieba() {
   }
@@ -115,6 +120,39 @@ class Jieba {
   }
 
  private:
+  static string pathJoin(const string& dir, const string& filename) {
+    if (dir.empty()) {
+        return filename;
+    }
+
+    char last_char = dir[dir.length() - 1];
+    if (last_char == '/' || last_char == '\\') {
+        return dir + filename;
+    } else {
+        #ifdef _WIN32
+        return dir + '\\' + filename;
+        #else
+        return dir + '/' + filename;
+        #endif
+    }
+  }
+
+  static string getCurrentDirectory() {
+    string path(__FILE__);
+    size_t pos = path.find_last_of("/\\");
+    return (pos == string::npos) ? "" : path.substr(0, pos);
+  }
+
+  static string getPath(const string& path, const string& default_file) {
+    if (path.empty()) {
+      string current_dir = getCurrentDirectory();
+      string parent_dir = current_dir.substr(0, current_dir.find_last_of("/\\"));
+      string grandparent_dir = parent_dir.substr(0, parent_dir.find_last_of("/\\"));
+      return pathJoin(pathJoin(grandparent_dir, "dict"), default_file);
+    }
+    return path;
+  }
+
   DictTrie dict_trie_;
   HMMModel model_;