diff --git a/nasal_ast.h b/nasal_ast.h
index fe381fa..0645345 100644
--- a/nasal_ast.h
+++ b/nasal_ast.h
@@ -14,7 +14,7 @@ enum ast_node
     ast_func,        // func keyword
     ast_hash,        // hash, basic value type
     ast_vec,         // vector, basic value type
-    ast_hashmember,  // elements in hashmap
+    ast_pair,        // pair of key and value in hashmap
     ast_call,        // mark a sub-tree of calling an identifier
     ast_callh,       // id.name
     ast_callv,       // id[index]
@@ -49,7 +49,7 @@ enum ast_node
     ast_forindex,    // forindex keyword
     ast_foreach,     // foreach keyword
     ast_while,       // while
-    ast_new_iter,    // iterator, used in forindex/foreach
+    ast_iter,        // iterator, used in forindex/foreach
     ast_conditional, // mark a sub-tree of conditional expression
     ast_if,          // if keyword
     ast_elsif,       // elsif keyword
diff --git a/nasal_codegen.h b/nasal_codegen.h
index 4e55786..d6708e9 100644
--- a/nasal_codegen.h
+++ b/nasal_codegen.h
@@ -294,7 +294,7 @@ void nasal_codegen::find_symbol(const nasal_ast& node)
         find_symbol(node[1]);
     }
     // find iterator(foreach, forindex), check
-    else if(node.type()==ast_new_iter)
+    else if(node.type()==ast_iter)
         add_sym(node[0].str());
     // check children
     else
@@ -528,7 +528,7 @@ void nasal_codegen::call_func(const nasal_ast& ast)
 {
     if(!ast.size())
         gen(op_callfv,0,ast.line());
-    else if(ast[0].type()==ast_hashmember)
+    else if(ast[0].type()==ast_pair)
     {
         hash_gen(ast);
         gen(op_callfh,0,ast.line());
@@ -847,7 +847,7 @@ void nasal_codegen::forindex_gen(const nasal_ast& ast)
     gen(op_cnt,0,ast[1].line());
     int ptr=code.size();
     gen(op_findex,0,ast.line());
-    if(ast[0].type()==ast_new_iter)
+    if(ast[0].type()==ast_iter)
     {
         const std::string& str=ast[0][0].str();
         local.empty()?
@@ -875,7 +875,7 @@ void nasal_codegen::foreach_gen(const nasal_ast& ast)
     gen(op_cnt,0,ast.line());
     int ptr=code.size();
     gen(op_feach,0,ast.line());
-    if(ast[0].type()==ast_new_iter)
+    if(ast[0].type()==ast_iter)
     {
         const std::string& str=ast[0][0].str();
         local.empty()?
diff --git a/nasal_err.h b/nasal_err.h
index c6edf71..d935e6e 100644
--- a/nasal_err.h
+++ b/nasal_err.h
@@ -67,11 +67,9 @@ public:
     {
         ++error;
         if(!line)
-        {
             std::cerr<<"["<<stage<<"] "<<file<<": "<<info<<'\n';
-            return;
-        }
-        std::cerr<<"["<<stage<<"] "<<file<<":"<<line<<" "<<info<<"\n"<<res[line-1]<<'\n';
+        else
+            std::cerr<<"["<<stage<<"] "<<file<<":"<<line<<" "<<info<<"\n"<<res[line-1]<<'\n';
     }
     void chkerr(){if(error)std::exit(1);}
 };
diff --git a/nasal_import.h b/nasal_import.h
index ca5715a..6bc8ff9 100644
--- a/nasal_import.h
+++ b/nasal_import.h
@@ -4,11 +4,11 @@
 class nasal_import
 {
 private:
-    nasal_err&               nerr;
+    nasal_err& nerr;
     std::vector<std::string> files;
-    bool      check_import(const nasal_ast&);
-    bool      check_exist(const std::string&);
-    void      linker(nasal_ast&,nasal_ast&&);
+    bool check_import(const nasal_ast&);
+    bool check_exist(const std::string&);
+    void linker(nasal_ast&,nasal_ast&&);
     nasal_ast file_import(nasal_ast&);
     nasal_ast load(nasal_ast&,uint16_t);
 public:
@@ -22,9 +22,9 @@ bool nasal_import::check_import(const nasal_ast& node)
 /*
 only this kind of node can be recognized as 'import':
     call
-        id:import
-        call_func
-            string:'filename'
+    |_id:import
+    |_call_func
+      |_string:'filename'
 */
     return (
         node.type()==ast_call &&
diff --git a/nasal_opt.h b/nasal_opt.h
index 037c3fe..afe7d06 100644
--- a/nasal_opt.h
+++ b/nasal_opt.h
@@ -20,14 +20,14 @@ void calc_const_num(nasal_ast& root)
     double res;
     switch(root.type())
     {
-        case ast_add:res=vec[0].num()+vec[1].num();break;
-        case ast_sub:res=vec[0].num()-vec[1].num();break;
-        case ast_mult:res=vec[0].num()*vec[1].num();break;
-        case ast_div:res=vec[0].num()/vec[1].num();break;
-        case ast_less:res=vec[0].num()<vec[1].num();break;
-        case ast_leq:res=vec[0].num()<=vec[1].num();break;
-        case ast_grt:res=vec[0].num()>vec[1].num();break;
-        case ast_geq:res=vec[0].num()>=vec[1].num();break;
+        case ast_add: res=vec[0].num()+vec[1].num(); break;
+        case ast_sub: res=vec[0].num()-vec[1].num(); break;
+        case ast_mult:res=vec[0].num()*vec[1].num(); break;
+        case ast_div: res=vec[0].num()/vec[1].num(); break;
+        case ast_less:res=vec[0].num()<vec[1].num(); break;
+        case ast_leq: res=vec[0].num()<=vec[1].num();break;
+        case ast_grt: res=vec[0].num()>vec[1].num(); break;
+        case ast_geq: res=vec[0].num()>=vec[1].num();break;
     }
     if(std::isinf(res) || std::isnan(res)) // inf and nan will cause number hashmap error in codegen
         return;
diff --git a/nasal_parse.h b/nasal_parse.h
index 32486b1..cc24262 100644
--- a/nasal_parse.h
+++ b/nasal_parse.h
@@ -63,7 +63,7 @@ private:
     nasal_ast id();
     nasal_ast vec();
     nasal_ast hash();
-    nasal_ast hmem();
+    nasal_ast pair();
     nasal_ast func();
     nasal_ast args();
     nasal_ast lcurve_expr();
@@ -305,7 +305,7 @@ nasal_ast nasal_parse::hash()
     match(tok_lbrace);
     while(tokens[ptr].type!=tok_rbrace)
     {
-        node.add(hmem());
+        node.add(pair());
         if(tokens[ptr].type==tok_comma)
             match(tok_comma);
         else if(tokens[ptr].type==tok_id || tokens[ptr].type==tok_str)// first set of hashmember
@@ -316,9 +316,9 @@ nasal_ast nasal_parse::hash()
     match(tok_rbrace,"expected \'}\' when generating hash");
     return node;
 }
-nasal_ast nasal_parse::hmem()
+nasal_ast nasal_parse::pair()
 {
-    nasal_ast node(tokens[ptr].line,ast_hashmember);
+    nasal_ast node(tokens[ptr].line,ast_pair);
     if(tokens[ptr].type==tok_id)
     {
         node.add(id());
@@ -715,7 +715,7 @@ nasal_ast nasal_parse::callf()
     match(tok_lcurve);
     while(tokens[ptr].type!=tok_rcurve)
     {
-        node.add(special_call?hmem():calc());
+        node.add(special_call?pair():calc());
         if(tokens[ptr].type==tok_comma)
             match(tok_comma);
         else if(tokens[ptr].type==tok_eof)
@@ -935,7 +935,7 @@ nasal_ast nasal_parse::iter_gen()
     if(tokens[ptr].type==tok_var)
     {
         match(tok_var);
-        node.set_type(ast_new_iter);
+        node.set_type(ast_iter);
         node.add(id());
         match(tok_id);
     }