diff --git a/nasal_ast.h b/nasal_ast.h
index 8e4e828..05e1762 100644
--- a/nasal_ast.h
+++ b/nasal_ast.h
@@ -145,6 +145,15 @@ const char* ast_name[]={
 };
 
 class ast {
+public:
+    ast(const ast&) = delete;
+    ast& operator=(const ast&) = delete;
+
+    ast(ast&&) = default;
+    ast& operator=(ast&&) = default;
+private:
+    void print(u32,bool,std::vector<string>&) const;
+
 private:
     span loc;
     u32 nd_type;
@@ -155,13 +164,8 @@ private:
 public:
     ast(const span& s,const u32 t)
         : loc(s),nd_type(t),nd_num(0),nd_str("") {}
-    ast(const ast&) = default;
-    ast(ast&&) = default;
-    ast& operator=(const ast&) = default;
-    ast& operator=(ast&&) = default;
 
     void dump() const;
-    void print(u32,bool,std::vector<string>&) const;
     void clear();
 
     ast& operator[](usize n) {return nd_child[n];}
@@ -169,7 +173,6 @@ public:
     usize size() const {return nd_child.size();}
     
     void add(ast&& node) {nd_child.push_back(std::move(node));}
-    void add(const ast& node) {nd_child.push_back(node);}
     void set_begin(const u32,const u32);
     void set_end(const u32,const u32);
     void set_type(const u32 t) {nd_type=t;}
@@ -177,14 +180,15 @@ public:
     void set_num(const f64 n) {nd_num=n;}
 
     u32 line() const {return loc.end_line;}
-    u32 col()  const {return loc.end_column;}
     u32 type() const {return nd_type;}
     f64 num()  const {return nd_num;}
     const string& str() const {return nd_str;}
     const string& file() const {return loc.file;}
     const span& location() const {return loc;}
+
     const std::vector<ast>& child() const {return nd_child;}
     std::vector<ast>& child() {return nd_child;}
+
     void update_span();
     void update_span(const span&);
 };
diff --git a/nasal_codegen.h b/nasal_codegen.h
index 371527f..aab6dd0 100644
--- a/nasal_codegen.h
+++ b/nasal_codegen.h
@@ -41,10 +41,12 @@ private:
     void regist_str(const string&);
     void find_symbol(const ast&);
     void add_sym(const string&);
-    i32  local_find(const string&);
-    i32  global_find(const string&);
-    i32  upvalue_find(const string&);
+    i32 local_find(const string&);
+    i32 global_find(const string&);
+    i32 upvalue_find(const string&);
+
     void gen(u8,u32,u32);
+
     void num_gen(const ast&);
     void str_gen(const ast&);
     void bool_gen(const ast&);
@@ -78,6 +80,7 @@ private:
     void calc_gen(const ast&);
     void block_gen(const ast&);
     void ret_gen(const ast&);
+
 public:
     codegen(error& e):fileindex(0),err(e),file(nullptr) {}
     const error& compile(const parse&,const linker&);
diff --git a/nasal_gc.h b/nasal_gc.h
index f3bff45..601b4de 100644
--- a/nasal_gc.h
+++ b/nasal_gc.h
@@ -18,6 +18,7 @@
 #include <vector>
 #include <unordered_map>
 #include <chrono>
+#include <algorithm>
 
 #include "nasal.h"
 #include "nasal_err.h"
@@ -713,26 +714,31 @@ void gc::clear() {
 }
 
 void gc::info() {
+    using std::left;
+    using std::setw;
+    using std::setfill;
     const char* name[]={"str  ","vec  ","hash ","func ","upval","obj  ","co   "};
-    std::clog<<"\ngarbage collector info (gc count|alloc count|memory size)\n";
+    std::clog<<"\ngc info (gc count|alloc count|memory size)\n";
 
-    u32 maxlen=0;
+    usize ident=0;
     for(u8 i=0;i<gc_type_size;++i) {
-        u32 len=std::to_string(gcnt[i]).length();
-        maxlen=maxlen<len?len:maxlen;
-        len=std::to_string(acnt[i]).length();
-        maxlen=maxlen<len?len:maxlen;
-        len=std::to_string(size[i]).length();
-        maxlen=maxlen<len?len:maxlen;
+        usize len=std::max({
+            std::to_string(gcnt[i]).length(),
+            std::to_string(acnt[i]).length(),
+            std::to_string(size[i]).length()
+        });
+        ident=ident<len?len:ident;
     }
 
     double total=0;
     for(u8 i=0;i<gc_type_size;++i) {
         if (gcnt[i] || acnt[i] || size[i]) {
             total+=gcnt[i];
-            std::clog<<" "<<name[i]<<" | "<<std::left<<std::setw(maxlen)<<std::setfill(' ')<<gcnt[i];
-            std::clog<<" | "<<std::left<<std::setw(maxlen)<<std::setfill(' ')<<acnt[i];
-            std::clog<<" | "<<std::left<<std::setw(maxlen)<<std::setfill(' ')<<size[i]<<"\n";
+            std::clog<<" "<<name[i];
+            std::clog<<" | "<<left<<setw(ident)<<setfill(' ')<<gcnt[i];
+            std::clog<<" | "<<left<<setw(ident)<<setfill(' ')<<acnt[i];
+            std::clog<<" | "<<left<<setw(ident)<<setfill(' ')<<size[i];
+            std::clog<<"\n";
         }
     }
 
@@ -745,14 +751,15 @@ void gc::info() {
 }
 
 var gc::alloc(u8 type) {
+    using clk=std::chrono::high_resolution_clock;
     const u8 index=type-vm_str;
     ++acnt[index];
     if (unused[index].empty()) {
         ++gcnt[index];
-        auto begin=std::chrono::high_resolution_clock::now();
+        auto begin=clk::now();
         mark();
         sweep();
-        worktime+=(std::chrono::high_resolution_clock::now()-begin).count();
+        worktime+=(clk::now()-begin).count();
     }
     if (unused[index].empty()) {
         extend(type);
diff --git a/nasal_opcode.h b/nasal_opcode.h
index 208d024..05ceb77 100644
--- a/nasal_opcode.h
+++ b/nasal_opcode.h
@@ -154,53 +154,57 @@ void codestream::set(const f64* numbuff,const string* strbuff,const string* file
 }
 
 void codestream::dump(std::ostream& out) const {
+    using std::setw;
+    using std::setfill;
+    using std::hex;
+    using std::dec;
     auto op=code.op;
     auto num=code.num;
-    out<<std::hex<<"0x"
-        <<std::setw(6)<<std::setfill('0')<<index<<"     "
-        <<std::setw(2)<<std::setfill('0')<<(u32)op<<" "
-        <<std::setw(2)<<std::setfill('0')<<((num>>16)&0xff)<<" "
-        <<std::setw(2)<<std::setfill('0')<<((num>>8)&0xff)<<" "
-        <<std::setw(2)<<std::setfill('0')<<(num&0xff)<<"     "
-        <<opname[op]<<"  "<<std::dec;
+    out<<hex<<"0x"
+        <<setw(6)<<setfill('0')<<index<<"     "
+        <<setw(2)<<setfill('0')<<(u32)op<<" "
+        <<setw(2)<<setfill('0')<<((num>>16)&0xff)<<" "
+        <<setw(2)<<setfill('0')<<((num>>8)&0xff)<<" "
+        <<setw(2)<<setfill('0')<<(num&0xff)<<"     "
+        <<opname[op]<<"  "<<dec;
     switch(op) {
         case op_addeq: case op_subeq:  case op_muleq: case op_diveq:
         case op_lnkeq: case op_meq: case op_btandeq: case op_btoreq:
         case op_btxoreq:
-            out<<std::hex<<"0x"<<num<<std::dec<<" sp-"<<num;break;
+            out<<hex<<"0x"<<num<<dec<<" sp-"<<num;break;
         case op_addeqc:case op_subeqc: case op_muleqc:case op_diveqc:
-            out<<std::hex<<"0x"<<num<<std::dec<<" ("<<nums[num]<<")";break;
+            out<<hex<<"0x"<<num<<dec<<" ("<<nums[num]<<")";break;
         case op_lnkeqc:
-            out<<std::hex<<"0x"<<num<<std::dec<<" ("<<rawstr(strs[num],16)<<")";break;
+            out<<hex<<"0x"<<num<<dec<<" ("<<rawstr(strs[num],16)<<")";break;
         case op_addecp:case op_subecp:case op_mulecp:case op_divecp:
-            out<<std::hex<<"0x"<<num<<std::dec<<" ("<<nums[num]<<") sp-1";break;
+            out<<hex<<"0x"<<num<<dec<<" ("<<nums[num]<<") sp-1";break;
         case op_lnkecp:
-            out<<std::hex<<"0x"<<num<<std::dec<<" ("<<rawstr(strs[num],16)<<") sp-1";break;
+            out<<hex<<"0x"<<num<<dec<<" ("<<rawstr(strs[num],16)<<") sp-1";break;
         case op_addc:  case op_subc:   case op_mulc:  case op_divc:
         case op_lessc: case op_leqc:   case op_grtc:  case op_geqc:
         case op_pnum:
-            out<<std::hex<<"0x"<<num<<std::dec<<" ("<<nums[num]<<")";break;
+            out<<hex<<"0x"<<num<<dec<<" ("<<nums[num]<<")";break;
         case op_callvi:case op_newv:   case op_callfv:
         case op_intg:  case op_intl:
         case op_findex:case op_feach:
         case op_newf:  case op_jmp:    case op_jt:    case op_jf:
         case op_callg: case op_mcallg: case op_loadg:
         case op_calll: case op_mcalll: case op_loadl:
-            out<<std::hex<<"0x"<<num<<std::dec;break;
+            out<<hex<<"0x"<<num<<dec;break;
         case op_callb:
-            out<<std::hex<<"0x"<<num<<" <"<<builtin[num].name
-                <<"@0x"<<(u64)builtin[num].func<<std::dec<<">";break;
+            out<<hex<<"0x"<<num<<" <"<<builtin[num].name
+                <<"@0x"<<(u64)builtin[num].func<<dec<<">";break;
         case op_upval: case op_mupval: case op_loadu:
-            out<<std::hex<<"0x"<<((num>>16)&0xffff)
-                <<"[0x"<<(num&0xffff)<<"]"<<std::dec;break;
+            out<<hex<<"0x"<<((num>>16)&0xffff)
+                <<"[0x"<<(num&0xffff)<<"]"<<dec;break;
         case op_happ:  case op_pstr:
         case op_lnkc:
         case op_callh: case op_mcallh:
         case op_para:  case op_deft:   case op_dyn:
-            out<<std::hex<<"0x"<<num<<std::dec<<" ("<<rawstr(strs[num],16)<<")";break;
+            out<<hex<<"0x"<<num<<dec<<" ("<<rawstr(strs[num],16)<<")";break;
         default:
             if (files) {
-                out<<std::hex<<"0x"<<num<<std::dec;
+                out<<hex<<"0x"<<num<<dec;
             }
             break;
     }
diff --git a/nasal_parse.h b/nasal_parse.h
index f7b2d20..38b35dc 100644
--- a/nasal_parse.h
+++ b/nasal_parse.h
@@ -1097,9 +1097,12 @@ ast parse::ret_expr() {
     ast node(toks[ptr].loc,ast_ret);
     match(tok::ret);
     tok type=toks[ptr].type;
-    if (type==tok::tknil || type==tok::num || type==tok::str || type==tok::id ||
-       type==tok::func || type==tok::sub || type==tok::opnot || type==tok::lcurve ||
-       type==tok::lbracket || type==tok::lbrace || type==tok::tktrue || type==tok::tkfalse
+    if (type==tok::tknil || type==tok::num ||
+        type==tok::str || type==tok::id ||
+        type==tok::func || type==tok::sub ||
+        type==tok::opnot || type==tok::lcurve ||
+        type==tok::lbracket || type==tok::lbrace ||
+        type==tok::tktrue || type==tok::tkfalse
     ) {
         node.add(calc());
     }