diff --git a/src/ast_dumper.cpp b/src/ast_dumper.cpp
index 900fdd8..a12a0e7 100644
--- a/src/ast_dumper.cpp
+++ b/src/ast_dumper.cpp
@@ -6,7 +6,7 @@ namespace nasal {
 
 bool ast_dumper::visit_use_stmt(use_stmt* node) {
     dump_indent();
-    std::cout << "use" << format_location(node->get_location());
+    std::cout << "use" << format_location(node);
     push_indent();
     for(auto i : node->get_path()) {
         if (i==node->get_path().back()) {
@@ -20,48 +20,48 @@ bool ast_dumper::visit_use_stmt(use_stmt* node) {
 
 bool ast_dumper::visit_null_expr(null_expr* node) {
     dump_indent();
-    std::cout << "null" << format_location(node->get_location());
+    std::cout << "null" << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_nil_expr(nil_expr* node) {
     dump_indent();
-    std::cout << "nil" << format_location(node->get_location());
+    std::cout << "nil" << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_number_literal(number_literal* node) {
     dump_indent();
     std::cout << "number " << node->get_number();
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_string_literal(string_literal* node) {
     dump_indent();
     std::cout << "string \"" << rawstr(node->get_content()) << "\"";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_identifier(identifier* node) {
     dump_indent();
     std::cout << "identifier " << node->get_name();
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_bool_literal(bool_literal* node) {
     dump_indent();
     std::cout << "bool " << node->get_flag();
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_vector_expr(vector_expr* node) {
     dump_indent();
     std::cout << "vector";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     for(auto i : node->get_elements()) {
         if (i==node->get_elements().back()) {
@@ -76,7 +76,7 @@ bool ast_dumper::visit_vector_expr(vector_expr* node) {
 bool ast_dumper::visit_hash_expr(hash_expr* node) {
     dump_indent();
     std::cout << "hash";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     for(auto i : node->get_members()) {
         if (i==node->get_members().back()) {
@@ -91,7 +91,7 @@ bool ast_dumper::visit_hash_expr(hash_expr* node) {
 bool ast_dumper::visit_hash_pair(hash_pair* node) {
     dump_indent();
     std::cout << "pair " << node->get_name();
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     if (node->get_value()) {
         push_indent();
         set_last();
@@ -104,7 +104,7 @@ bool ast_dumper::visit_hash_pair(hash_pair* node) {
 bool ast_dumper::visit_function(function* node) {
     dump_indent();
     std::cout << "function";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     for(auto i : node->get_parameter_list()) {
         i->accept(this);
@@ -118,7 +118,7 @@ bool ast_dumper::visit_function(function* node) {
 bool ast_dumper::visit_code_block(code_block* node) {
     dump_indent();
     std::cout << "block";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     for(auto i : node->get_expressions()) {
         if (i==node->get_expressions().back()) {
@@ -133,7 +133,7 @@ bool ast_dumper::visit_code_block(code_block* node) {
 bool ast_dumper::visit_parameter(parameter* node) {
     dump_indent();
     std::cout << "parameter " << node->get_parameter_name();
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     if (node->get_default_value()) {
         push_indent();
         set_last();
@@ -146,7 +146,7 @@ bool ast_dumper::visit_parameter(parameter* node) {
 bool ast_dumper::visit_ternary_operator(ternary_operator* node) {
     dump_indent();
     std::cout << "ternary_operator";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     node->get_condition()->accept(this);
     node->get_left()->accept(this);
@@ -166,7 +166,7 @@ bool ast_dumper::visit_binary_operator(binary_operator* node) {
         return true;
     }
     dump_indent();
-    std::cout << "binary_operator ";
+    std::cout << "binary_operator \"";
     switch(node->get_operator_type()) {
         case binary_operator::binary_type::add: std::cout << "+"; break;
         case binary_operator::binary_type::sub: std::cout << "-"; break;
@@ -185,7 +185,7 @@ bool ast_dumper::visit_binary_operator(binary_operator* node) {
         case binary_operator::binary_type::condition_and: std::cout << "and"; break;
         case binary_operator::binary_type::condition_or: std::cout << "or"; break;
     }
-    std::cout << format_location(node->get_location());
+    std::cout << "\"" << format_location(node);
     push_indent();
     node->get_left()->accept(this);
     set_last();
@@ -200,13 +200,13 @@ bool ast_dumper::visit_unary_operator(unary_operator* node) {
         return true;
     }
     dump_indent();
-    std::cout << "unary_operator ";
+    std::cout << "unary_operator \"";
     switch(node->get_operator_type()) {
         case unary_operator::unary_type::negative: std::cout << "-"; break;
         case unary_operator::unary_type::logical_not: std::cout << "!"; break;
         case unary_operator::unary_type::bitwise_not: std::cout << "~"; break;
     }
-    std::cout << format_location(node->get_location());
+    std::cout << "\"" << format_location(node);
     push_indent();
     set_last();
     node->get_value()->accept(this);
@@ -217,7 +217,7 @@ bool ast_dumper::visit_unary_operator(unary_operator* node) {
 bool ast_dumper::visit_call_expr(call_expr* node) {
     dump_indent();
     std::cout << "call_expr";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     if (!node->get_calls().size()) {
         set_last();
@@ -236,14 +236,14 @@ bool ast_dumper::visit_call_expr(call_expr* node) {
 bool ast_dumper::visit_call_hash(call_hash* node) {
     dump_indent();
     std::cout << "call_hash " << node->get_field();
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_call_vector(call_vector* node) {
     dump_indent();
     std::cout << "call_vector";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     for(auto i : node->get_slices()) {
         if (i==node->get_slices().back()) {
@@ -258,7 +258,7 @@ bool ast_dumper::visit_call_vector(call_vector* node) {
 bool ast_dumper::visit_call_function(call_function* node) {
     dump_indent();
     std::cout << "call_function";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     for(auto i : node->get_argument()) {
         if (i==node->get_argument().back()) {
@@ -273,7 +273,7 @@ bool ast_dumper::visit_call_function(call_function* node) {
 bool ast_dumper::visit_slice_vector(slice_vector* node) {
     dump_indent();
     std::cout << "slice";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     if (!node->get_end()) {
         set_last();
@@ -290,7 +290,7 @@ bool ast_dumper::visit_slice_vector(slice_vector* node) {
 bool ast_dumper::visit_definition_expr(definition_expr* node) {
     dump_indent();
     std::cout << "definition";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     if (node->get_variable_name()) {
         node->get_variable_name()->accept(this);
@@ -321,7 +321,7 @@ bool ast_dumper::visit_assignment_expr(assignment_expr* node) {
         case assignment_expr::assign_type::bitwise_or_equal: std::cout << "|="; break;
         case assignment_expr::assign_type::bitwise_xor_equal: std::cout << "^="; break;
     }
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     node->get_left()->accept(this);
     set_last();
@@ -333,7 +333,7 @@ bool ast_dumper::visit_assignment_expr(assignment_expr* node) {
 bool ast_dumper::visit_multi_identifier(multi_identifier* node) {
     dump_indent();
     std::cout << "multiple_identifier";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     for(auto i : node->get_variables()) {
         if (i==node->get_variables().back()) {
@@ -348,7 +348,7 @@ bool ast_dumper::visit_multi_identifier(multi_identifier* node) {
 bool ast_dumper::visit_tuple_expr(tuple_expr* node) {
     dump_indent();
     std::cout << "tuple";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     for(auto i : node->get_elements()) {
         if (i==node->get_elements().back()) {
@@ -363,7 +363,7 @@ bool ast_dumper::visit_tuple_expr(tuple_expr* node) {
 bool ast_dumper::visit_multi_assign(multi_assign* node) {
     dump_indent();
     std::cout << "multiple_assignment";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     node->get_tuple()->accept(this);
     set_last();
@@ -375,7 +375,7 @@ bool ast_dumper::visit_multi_assign(multi_assign* node) {
 bool ast_dumper::visit_while_expr(while_expr* node) {
     dump_indent();
     std::cout << "while";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     node->get_condition()->accept(this);
     set_last();
@@ -387,7 +387,7 @@ bool ast_dumper::visit_while_expr(while_expr* node) {
 bool ast_dumper::visit_for_expr(for_expr* node) {
     dump_indent();
     std::cout << "for";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     node->get_initial()->accept(this);
     node->get_condition()->accept(this);
@@ -405,7 +405,7 @@ bool ast_dumper::visit_iter_expr(iter_expr* node) {
     } else {
         std::cout << "iterator";
     }
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     set_last();
     if (node->get_name()) {
@@ -424,7 +424,7 @@ bool ast_dumper::visit_forei_expr(forei_expr* node) {
     } else {
         std::cout << "forindex";
     }
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     node->get_iterator()->accept(this);
     node->get_value()->accept(this);
@@ -437,7 +437,7 @@ bool ast_dumper::visit_forei_expr(forei_expr* node) {
 bool ast_dumper::visit_condition_expr(condition_expr* node) {
     dump_indent();
     std::cout << "condition";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     if (!node->get_elsif_stataments().size() &&
         !node->get_else_statement()) {
@@ -462,7 +462,7 @@ bool ast_dumper::visit_condition_expr(condition_expr* node) {
 bool ast_dumper::visit_if_expr(if_expr* node) {
     dump_indent();
     std::cout << "if";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     push_indent();
     if (node->get_condition()) {
         node->get_condition()->accept(this);
@@ -476,21 +476,21 @@ bool ast_dumper::visit_if_expr(if_expr* node) {
 bool ast_dumper::visit_continue_expr(continue_expr* node) {
     dump_indent();
     std::cout << "continue";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_break_expr(break_expr* node) {
     dump_indent();
     std::cout << "break";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     return true;
 }
 
 bool ast_dumper::visit_return_expr(return_expr* node) {
     dump_indent();
     std::cout << "return";
-    std::cout << format_location(node->get_location());
+    std::cout << format_location(node);
     if (node->get_value()) {
         push_indent();
         set_last();
diff --git a/src/ast_dumper.h b/src/ast_dumper.h
index c762f79..5825ed7 100644
--- a/src/ast_dumper.h
+++ b/src/ast_dumper.h
@@ -16,29 +16,37 @@ private:
 private:
     void push_indent() {
         if (indent.size()) {
-            if (indent.back()=="|--") {
-                indent.back() = "|  ";
-            } else if (indent.back()=="+--") {
+            if (indent.back()=="├──") {
+                indent.back() = "│  ";
+            } else if (indent.back()=="└──") {
                 indent.back() = "   ";
             }
         }
-        indent.push_back("|--");
+        indent.push_back("├──");
     }
-    void pop_indent() {indent.pop_back();}
-    void set_last() {indent.back() = "+--";}
+
+    void pop_indent() {
+        indent.pop_back();
+    }
+
+    void set_last() {
+        indent.back() = "└──";
+    }
+
     void dump_indent() {
-        if (indent.size() && indent.back()=="|  ") {
-            indent.back() = "|--";
+        if (indent.size() && indent.back()=="│  ") {
+            indent.back() = "├──";
         }
         for(const auto& i : indent) {
             std::cout << i;
         }
     }
-    std::string format_location(const span& location) {
+
+    std::string format_location(expr* node) {
         std::stringstream ss;
-        ss << " -> ";
-        location.dump_begin(ss);
-        ss << "\n";
+        ss << " → [";
+        node->get_location().dump_begin(ss);
+        ss << "]\n";
         return ss.str();
     }
 
diff --git a/src/main.cpp b/src/main.cpp
index 422cd27..2108732 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -45,7 +45,7 @@ std::ostream& help(std::ostream& out) {
     << "option:\n"
     << "   -h,   --help     | get help.\n"
     << "   -v,   --version  | get version.\n"
-    << "   -r,   --repl     | use repl interpreter(experimental).\n"
+    << "   -r,   --repl     | use repl interpreter.\n"
     << "\nnasal [option] <file> [argv]\n"
     << "option:\n"
     << "   -a,   --ast      | view ast after link/optimize process.\n"
@@ -101,11 +101,12 @@ std::ostream& version(std::ostream& out) {
     for(u32 i = 0; i<5; ++i) {
         num = (num+rand())*(1.0/(RAND_MAX+1.0));
     }
-    if (num<0.01) {
+    // give you 5% to see this easter egg
+    if (num<0.05) {
         nasal::parse::easter_egg();
     }
 
-    out << "nasal interpreter version " << __nasver__;
+    out << "nasal version " << __nasver__;
     out << " " << nasal::get_platform() << " " << nasal::get_arch();
     out << " (" << __DATE__ << " " << __TIME__ << ")\n";
     return out;