diff --git a/version2.0/abstract_syntax_tree.h b/version2.0/abstract_syntax_tree.h
index 68268fb..7b74141 100644
--- a/version2.0/abstract_syntax_tree.h
+++ b/version2.0/abstract_syntax_tree.h
@@ -119,7 +119,10 @@ void abstract_syntax_tree::set_type(const int __type)
 
 void abstract_syntax_tree::set_line(const int __line)
 {
-	line=__line;
+	if(__line>=0)
+		line=__line;
+	else
+		line=0;
 	return;
 }
 
@@ -143,6 +146,9 @@ void abstract_syntax_tree::set_name(std::string __str)
 
 void abstract_syntax_tree::add_child(abstract_syntax_tree p)
 {
+	// use abstract_syntax_tree instead of abstract_syntax_tree&
+	// because when this function get a 'p' from returned value of
+	// another function,this may result in s SIGSEGV.
 	children.push_back(p);
 	return;
 }
diff --git a/version2.0/main.cpp b/version2.0/main.cpp
index f292511..df06f97 100644
--- a/version2.0/main.cpp
+++ b/version2.0/main.cpp
@@ -22,8 +22,8 @@ int main()
 			std::cout<<">> [lib   ] add lib file."<<std::endl;
 			std::cout<<">> [rs    ] print resource code."<<std::endl;
 			std::cout<<">> [total ] print resource code with lib code."<<std::endl;
-			std::cout<<">> [lexer ] turn code into tokens."<<std::endl;
-			std::cout<<">> [parser] turn tokens into abstract syntax tree."<<std::endl;
+			std::cout<<">> [lex   ] turn code into tokens."<<std::endl;
+			std::cout<<">> [par   ] turn tokens into abstract syntax tree."<<std::endl;
 			std::cout<<">> [ast   ] check the abstract syntax tree."<<std::endl;
 			std::cout<<">> [run   ] run code."<<std::endl;
 			std::cout<<">> [exit  ] quit nasal interpreter."<<std::endl;
@@ -61,7 +61,7 @@ int main()
 		{
 			resource.print_resource(true);
 		}
-		else if(command=="lexer")
+		else if(command=="lex")
 		{
 			lexer.scanner(resource.get_source());
 			lexer.generate_detail_token();
@@ -70,7 +70,7 @@ int main()
 			else
 				std::cout<<">>[Lexer] error occurred,stop."<<std::endl;
 		}
-		else if(command=="parser")
+		else if(command=="par")
 		{
 			lexer.scanner(resource.get_source());
 			lexer.generate_detail_token();
@@ -99,6 +99,24 @@ int main()
 			else
 				std::cout<<">>[Lexer] error occurred,stop."<<std::endl;
 		}
+		else if(command=="run")
+		{
+			lexer.scanner(resource.get_source());
+			lexer.generate_detail_token();
+			if(!lexer.get_error())
+			{
+				parser.get_token_list(lexer.get_detail_token_list());
+				parser.main_generate();
+				if(!parser.get_error())
+				{
+					// run code
+				}
+				else
+					std::cout<<">>[Parse] error occurred,stop."<<std::endl;
+			}
+			else
+				std::cout<<">>[Lexer] error occurred,stop."<<std::endl;
+		}
 		else if(command=="exit")
 			break;
 		else
diff --git a/version2.0/nasal_enum.h b/version2.0/nasal_enum.h
index 0a097bc..bfad46f 100644
--- a/version2.0/nasal_enum.h
+++ b/version2.0/nasal_enum.h
@@ -25,6 +25,7 @@ void print_lexer_token(int type)
 enum parse_token_type
 {
 	__stack_end=1,
+	__stack_top,
 	__cmp_equal,__cmp_not_equal,__cmp_less,__cmp_less_or_equal,__cmp_more,__cmp_more_or_equal,
 	// == != < <= > >= 
 	__and_operator,__or_operator,__nor_operator,__add_operator,__sub_operator,__mul_operator,__div_operator,__link_operator,
@@ -62,6 +63,7 @@ void print_parse_token(int type)
 	switch(type)
 	{
 		case __stack_end:         context="#";  break;
+		case __stack_top:         context="#";  break;
 		
 		case __cmp_equal:         context="=="; break;
 		case __cmp_not_equal:     context="!="; break;
@@ -141,4 +143,30 @@ void print_parse_token(int type)
 	return;
 }
 
+enum parse_error_type
+{
+	parse_unknown_error, // unknown error
+	error_token_in_main, // when a token should not be the begin of a statement in main
+	definition_lack_var, // lack 'var' reserve word
+	definition_lack_id,  // lack identifier
+};
+
+void print_parse_error(int error_type,int line,int error_token_type=__stack_end)
+{
+	std::string error_info_head=">>[Parse-error] line ";
+	switch(error_type)
+	{
+		case parse_unknown_error: std::cout<<error_info_head<<line<<": unknown parse error. error id: parse_unknown_error."<<std::endl;break;
+		case error_token_in_main:
+			std::cout<<error_info_head<<line<<": statements should not begin with \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' in main scope."<<std::endl;
+			break;
+		case definition_lack_var: std::cout<<error_info_head<<line<<": expect a \'var\' here."<<std::endl;break;
+		case definition_lack_id:  std::cout<<error_info_head<<line<<": expect identifier(s) after \'var\'."<<std::endl;break;
+		default:                  std::cout<<error_info_head<<line<<": unknown parse error. error id: other_type."<<std::endl;break;
+	}
+	return;
+}
+
 #endif
diff --git a/version2.0/nasal_parse.h b/version2.0/nasal_parse.h
index c71f4a2..045e0fa 100644
--- a/version2.0/nasal_parse.h
+++ b/version2.0/nasal_parse.h
@@ -91,6 +91,7 @@ void nasal_parse::get_token()
 	{
 		this_token.type=__stack_end;
 		this_token.str="__stack_end";
+		std::cout<<">>[Parse-error] fatal error occurred."<<std::endl;
 		std::cout<<">>[Parse-error] empty token stack."<<std::endl;
 	}
 	return;
@@ -105,7 +106,10 @@ void nasal_parse::push_token()
 		checked_tokens.pop();
 	}
 	else
-		std::cout<<">>[Parse-error] empty checked token stack."<<std::endl;
+	{
+		std::cout<<">>[Parse-error] fatal error occurred."<<std::endl;
+		std::cout<<">>[Parse-error] empty checked-token stack."<<std::endl;
+	}
 	return;
 }
 
@@ -116,6 +120,7 @@ int nasal_parse::get_error()
 
 abstract_syntax_tree& nasal_parse::get_root()
 {
+	std::cout<<">>[Abstract-syntax-tree] get root address: "<<(&root)<<" ."<<std::endl;
 	return root;
 }
 
@@ -190,6 +195,7 @@ abstract_syntax_tree nasal_parse::var_outside_definition()
 	abstract_syntax_tree definition_node;
 	definition_node.set_type(__definition);
 	this->get_token();
+	definition_node.set_line(this_token.line);
 	if(this_token.type!=__var)
 	{
 		++error;
@@ -215,6 +221,7 @@ abstract_syntax_tree nasal_parse::loop_expr()
 	abstract_syntax_tree loop_main_node;
 	loop_main_node.set_type(__loop);
 	this->get_token();
+	loop_main_node.set_line(this_token.line);
 	switch(this_token.type)
 	{
 		case __for:
@@ -229,6 +236,8 @@ abstract_syntax_tree nasal_parse::choose_expr()
 {
 	abstract_syntax_tree choose_main_node;
 	choose_main_node.set_type(__ifelse);
+	this->get_token();
+	choose_main_node.set_line(this_token.line);
 	return choose_main_node;
 }
 #endif
diff --git a/version2.0/test.nas b/version2.0/test.nas
index 57672b0..175f6d5 100644
--- a/version2.0/test.nas
+++ b/version2.0/test.nas
@@ -1,3 +1,20 @@
+# basic type
+nil;
+2147483647;
+0x7fffffff;
+0xdeadbeef;
+0o70120327;
+"hello world!";
+'hello world!';
+-12;
+!0;
+-((30));
+[];
+{};
+[0,1,2,3,4,5][2];     # 2
+{str:"hello"}.str;    # "hello"
+{str:"hello"}["str"]; # "hello"
+
 # normal scalar
 var number_1=1;
 var number_2=0xdeadbeef;
@@ -5,6 +22,7 @@ var number_3=0x13702;
 var number_4=0.12341490239423;
 var string_1="hello";
 var string_2='hello';
+var string_3=number_1? 'yes':'no'; # yes
 
 # vector
 var vector_1=[];
@@ -51,14 +69,18 @@ print(source['member_2']());
 print(source.member_2());
 
 var test_func=func{return 1;}
-print(func test_func()); # 1
-print(test_func());      # 1
-print(func test_func);   # nothing
-print(test_func);        # nothing
+print(func test_func());       # 1
+print(test_func());            # 1
+print(func test_func);         # nothing
+print(test_func);              # nothing
+print(([0,1,2,3])[1]);         # 1
+print(({str:"what?"})["str"]); # what?
+print(({str:"what?"}).str);    # what?
 
 # lambda
 (func(x){return x>0? x:0;})(12);
 (func{print("hello world");})();
+(((func(x){return 1.0/math.exp(x);})))(0);
 
 # flexible definition & assignment
 var (r,g,b)=[0x00,0x10,0xff];
@@ -67,4 +89,23 @@ var color=[0x00,0x10,0xff];
 var (r,g,b)=color;
 (var r,g,b)=color;
 (r,g,b)=(b,g,r);
-(number_1,number_2)=(number_2,number_1);
\ No newline at end of file
+(number_1,number_2)=(number_2,number_1);
+
+# calculation
+1+1;
+1+1-2+3-4+5-6;
+1+1*8-9/3;
+1*(1+2*(3+4*(5+6*(7+8*(9+10/(1+1))))));
+((-1*2+9))/7-1;
+((({num:2})))["num"]*2*2*2;
+((((([0,1,2])[0:2]))[0:2]))[1]-1;
+(((((((((((((((((((1+1+2+3+5)+8))+13)))+21))))+34)))))+55))))*89;
+number_1*(number_2+number_3)/90-number_4;
+(func test_func)()-1;
+hash_3.member_3+(func {return {what:"i don't tell you.",case_small:80,case_large:100}})["case_large"]/10;
+-1*10+5 or 10-10;
+nil and 1+7*8;
+(number_1 or number_2) and (number_3 or number_4-number_4*1);
+[0,1,4,3,2][4]*2-4+1*2*2*2*2*2/8;
+{num:0}.num or {what_is_the_secret_of_universe:42}["what_is_the_secret_of_universe"];
+"123"~"456"-123456*2/2;
\ No newline at end of file