Dump LeafGreen encounters

tools/jsonproc/jsonproc.cpp

@@ -39,6 +39,13 @@ int main(int argc, char *argv[])
         return "//\n// DO NOT MODIFY THIS FILE! It is auto-generated from " + jsonfilepath +" and Inja template " + templateFilepath + "\n//\n";
     });
 
+    env.add_callback("contains", 2, [](Arguments& args) {
+        string word = args.at(0)->get<string>();
+        string check = args.at(1)->get<string>();
+
+        return word.find(check) != std::string::npos;
+    });
+
     env.add_callback("subtract", 2, [](Arguments& args) {
         int minuend = args.at(0)->get<int>();
         int subtrahend = args.at(1)->get<int>();