From a0a22f701d69de1eb6caa863161ad3a9f792c2b7 Mon Sep 17 00:00:00 2001
From: Valk Richard Li <48872266+ValKmjolnir@users.noreply.github.com>
Date: Sat, 14 Nov 2020 00:33:11 +0800
Subject: [PATCH] update

---
 nasal_builtin.h | 120 +++++++++++++++---------------------------
 nasal_gc.h      | 137 +++++++++++++++++-------------------------------
 nasal_runtime.h |  87 ++++++++++--------------------
 3 files changed, 117 insertions(+), 227 deletions(-)

diff --git a/nasal_builtin.h b/nasal_builtin.h
index 48a0f0b..9471898 100644
--- a/nasal_builtin.h
+++ b/nasal_builtin.h
@@ -32,8 +32,7 @@ int nasal_runtime::builtin_print(int local_scope_addr)
     }
     std::cout<<"\n";
     // generate return value
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 int nasal_runtime::builtin_append(int local_scope_addr)
@@ -61,8 +60,7 @@ int nasal_runtime::builtin_append(int local_scope_addr)
         nasal_vm.add_reference(value_address);
         ref_vector.add_elem(value_address);
     }
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 int nasal_runtime::builtin_setsize(int local_scope_addr)
@@ -121,12 +119,10 @@ int nasal_runtime::builtin_setsize(int local_scope_addr)
     else if(number>vec_size)
         for(int i=vec_size;i<number;++i)
         {
-            int new_val_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(new_val_addr).set_type(vm_nil);
+            int new_val_addr=nasal_vm.gc_alloc(vm_nil);
             ref_vector.add_elem(new_val_addr);
         }
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 
@@ -147,15 +143,13 @@ int nasal_runtime::builtin_system(int local_scope_addr)
     command[size]='\0';
     system(command);
     delete []command;
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 
 int nasal_runtime::builtin_input(int local_scope_addr)
 {
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_string);
+    int ret_addr=nasal_vm.gc_alloc(vm_string);
     std::string str;
     std::cin>>str;
     nasal_vm.gc_get(ret_addr).set_string(str);
@@ -186,8 +180,7 @@ int nasal_runtime::builtin_sleep(int local_scope_addr)
     else
         sleep_time=(unsigned long)nasal_vm.gc_get(value_addr).get_number();
     sleep(sleep_time); // sleep in unistd.h will make this progress sleep sleep_time seconds.
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 
@@ -214,8 +207,7 @@ int nasal_runtime::builtin_finput(int local_scope_addr)
     else
         file_content="";
     fin.close();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_string);
+    int ret_addr=nasal_vm.gc_alloc(vm_string);
     nasal_vm.gc_get(ret_addr).set_string(file_content);
     return ret_addr;
 }
@@ -241,8 +233,7 @@ int nasal_runtime::builtin_foutput(int local_scope_addr)
     std::ofstream fout(filename);
     fout<<file_content;
     fout.close();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 
@@ -267,8 +258,7 @@ int nasal_runtime::builtin_split(int local_scope_addr)
     int delimeter_len=delimeter.length();
     int source_len=source.length();
 
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_vector);
+    int ret_addr=nasal_vm.gc_alloc(vm_vector);
     nasal_vector& ref_vec=nasal_vm.gc_get(ret_addr).get_vector();
     std::string tmp="";
 
@@ -277,8 +267,7 @@ int nasal_runtime::builtin_split(int local_scope_addr)
         for(int i=0;i<source_len;++i)
         {
             tmp+=source[i];
-            int str_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(str_addr).set_type(vm_string);
+            int str_addr=nasal_vm.gc_alloc(vm_string);
             nasal_vm.gc_get(str_addr).set_string(tmp);
             ref_vec.add_elem(str_addr);
             tmp="";
@@ -299,8 +288,7 @@ int nasal_runtime::builtin_split(int local_scope_addr)
             }
         if(check_delimeter)
         {
-            int str_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(str_addr).set_type(vm_string);
+            int str_addr=nasal_vm.gc_alloc(vm_string);
             nasal_vm.gc_get(str_addr).set_string(tmp);
             ref_vec.add_elem(str_addr);
             tmp="";
@@ -311,8 +299,7 @@ int nasal_runtime::builtin_split(int local_scope_addr)
     }
     if(tmp.length())
     {
-        int str_addr=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(str_addr).set_type(vm_string);
+        int str_addr=nasal_vm.gc_alloc(vm_string);
         nasal_vm.gc_get(str_addr).set_string(tmp);
         ref_vec.add_elem(str_addr);
         tmp="";
@@ -332,15 +319,13 @@ int nasal_runtime::builtin_rand(int local_scope_addr)
     {
         unsigned int number=(unsigned int)nasal_vm.gc_get(value_addr).get_number();
         srand(number);
-        int ret_addr=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+        int ret_addr=nasal_vm.gc_alloc(vm_nil);
         return ret_addr;
     }
     double num=0;
     for(int i=0;i<5;++i)
         num=(num+rand())*(1.0/(RAND_MAX+1.0));
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(num);
     return ret_addr;
 }
@@ -353,8 +338,7 @@ int nasal_runtime::builtin_id(int local_scope_addr)
         ++error;
         return -1;
     }
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)value_addr);
     return ret_addr;
 }
@@ -368,8 +352,7 @@ int nasal_runtime::builtin_int(int local_scope_addr)
         return -1;
     }
     int number=(int)nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)number);
     return ret_addr;
 }
@@ -383,8 +366,7 @@ int nasal_runtime::builtin_num(int local_scope_addr)
         return -1;
     }
     std::string str=nasal_vm.gc_get(value_addr).get_string();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(trans_string_to_number(str));
     return ret_addr;
 }
@@ -410,8 +392,7 @@ int nasal_runtime::builtin_str(int local_scope_addr)
         return -1;
     }
     double number=nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_string);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_string(trans_number_to_string(number));
     return ret_addr;
 }
@@ -436,12 +417,12 @@ int nasal_runtime::builtin_size(int local_scope_addr)
         case vm_vector:number=nasal_vm.gc_get(value_addr).get_vector().size();break;
         case vm_hash:number=nasal_vm.gc_get(value_addr).get_hash().size();break;
     }
-    int ret_addr=nasal_vm.gc_alloc();
+    int ret_addr=-1;
     if(number<0)
-        nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+        ret_addr=nasal_vm.gc_alloc(vm_nil);
     else
     {
-        nasal_vm.gc_get(ret_addr).set_type(vm_number);
+        ret_addr=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(ret_addr).set_number((double)number);
     }
     return ret_addr;
@@ -464,8 +445,7 @@ int nasal_runtime::builtin_xor(int local_scope_addr)
     }
     int number_a=(int)nasal_vm.gc_get(a_addr).get_number();
     int number_b=(int)nasal_vm.gc_get(b_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)(number_a^number_b));
     return ret_addr;
 }
@@ -487,8 +467,7 @@ int nasal_runtime::builtin_and(int local_scope_addr)
     }
     int number_a=(int)nasal_vm.gc_get(a_addr).get_number();
     int number_b=(int)nasal_vm.gc_get(b_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)(number_a&number_b));
     return ret_addr;
 }
@@ -510,8 +489,7 @@ int nasal_runtime::builtin_or(int local_scope_addr)
     }
     int number_a=(int)nasal_vm.gc_get(a_addr).get_number();
     int number_b=(int)nasal_vm.gc_get(b_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)(number_a|number_b));
     return ret_addr;
 }
@@ -533,8 +511,7 @@ int nasal_runtime::builtin_nand(int local_scope_addr)
     }
     int number_a=(int)nasal_vm.gc_get(a_addr).get_number();
     int number_b=(int)nasal_vm.gc_get(b_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)(~(number_a&number_b)));
     return ret_addr;
 }
@@ -548,8 +525,7 @@ int nasal_runtime::builtin_not(int local_scope_addr)
         return -1;
     }
     int number=(int)nasal_vm.gc_get(a_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)(~number));
     return ret_addr;
 }
@@ -563,8 +539,7 @@ int nasal_runtime::builtin_sin(int local_scope_addr)
         return -1;
     }
     double number=nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(sin(number));
     return ret_addr;
 }
@@ -578,8 +553,7 @@ int nasal_runtime::builtin_cos(int local_scope_addr)
         return -1;
     }
     double number=nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(cos(number));
     return ret_addr;
 }
@@ -593,8 +567,7 @@ int nasal_runtime::builtin_tan(int local_scope_addr)
         return -1;
     }
     double number=nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(tan(number));
     return ret_addr;
 }
@@ -608,8 +581,7 @@ int nasal_runtime::builtin_exp(int local_scope_addr)
         return -1;
     }
     double number=nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(exp(number));
     return ret_addr;
 }
@@ -623,8 +595,7 @@ int nasal_runtime::builtin_ln(int local_scope_addr)
         return -1;
     }
     double number=nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(log(number)/log(2.7182818284590452354));
     return ret_addr;
 }
@@ -638,8 +609,7 @@ int nasal_runtime::builtin_sqrt(int local_scope_addr)
         return -1;
     }
     double number=nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(sqrt(number));
     return ret_addr;
 }
@@ -661,8 +631,7 @@ int nasal_runtime::builtin_atan2(int local_scope_addr)
     }
     double x=nasal_vm.gc_get(x_value_addr).get_number();
     double y=nasal_vm.gc_get(y_value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number(atan2(y,x));
     return ret_addr;
 }
@@ -676,8 +645,7 @@ int nasal_runtime::builtin_time(int local_scope_addr)
         return -1;
     }
     time_t begin_time=(time_t)nasal_vm.gc_get(value_addr).get_number();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)time(&begin_time));
     return ret_addr;
 }
@@ -699,8 +667,7 @@ int nasal_runtime::builtin_contains(int local_scope_addr)
     }
     std::string key=nasal_vm.gc_get(key_addr).get_string();
     bool contains=nasal_vm.gc_get(hash_addr).get_hash().check_contain(key);
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    int ret_addr=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(ret_addr).set_number((double)contains);
     return ret_addr;
 }
@@ -722,8 +689,7 @@ int nasal_runtime::builtin_delete(int local_scope_addr)
     }
     std::string key=nasal_vm.gc_get(key_addr).get_string();
     nasal_vm.gc_get(hash_addr).get_hash().del_elem(key);
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 int nasal_runtime::builtin_getkeys(int local_scope_addr)
@@ -744,8 +710,7 @@ int nasal_runtime::builtin_import(int local_scope_addr)
     // this function will return nothing when running.
     ++error;
     std::cout<<">> [runtime] builtin_import: cannot use import when running.\n";
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 int nasal_runtime::builtin_die(int local_scope_addr)
@@ -759,8 +724,7 @@ int nasal_runtime::builtin_die(int local_scope_addr)
     }
     ++error;
     std::cout<<">> [runtime] error: "<<nasal_vm.gc_get(str_addr).get_string()<<'\n';
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+    int ret_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_addr;
 }
 int nasal_runtime::builtin_type(int local_scope_addr)
@@ -773,8 +737,7 @@ int nasal_runtime::builtin_type(int local_scope_addr)
         return -1;
     }
     int type=nasal_vm.gc_get(value_addr).get_type();
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_string);
+    int ret_addr=nasal_vm.gc_alloc(vm_string);
     switch(type)
     {
         case vm_nil:      nasal_vm.gc_get(ret_addr).set_string("nil");break;
@@ -821,8 +784,7 @@ int nasal_runtime::builtin_substr(int local_scope_addr)
     std::string tmp="";
     for(int i=begin;i<begin+len;++i)
         tmp+=str[i];
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_string);
+    int ret_addr=nasal_vm.gc_alloc(vm_string);
     nasal_vm.gc_get(ret_addr).set_string(tmp);
     return ret_addr;
 }
diff --git a/nasal_gc.h b/nasal_gc.h
index 3df24a5..24612e0 100644
--- a/nasal_gc.h
+++ b/nasal_gc.h
@@ -91,7 +91,7 @@ public:
     nasal_scalar();
     ~nasal_scalar();
     void clear();
-    bool set_type(int);
+    void set_type(int);
     void set_number(double);
     void set_string(std::string);
     int             get_type();
@@ -143,11 +143,10 @@ public:
     ~nasal_virtual_machine();
     void clear();
     void debug();
-    int gc_alloc();             // garbage collector gives a new space
+    int gc_alloc(int);          // garbage collector gives a new space
     nasal_scalar& gc_get(int);  // get scalar that stored in gc
     void add_reference(int);
     void del_reference(int);
-    int get_refcnt(int);
     int mem_alloc();            // memory gives a new space
     int mem_free(int);          // give space back to memory
     int mem_change(int,int);    // change value in memory space
@@ -340,8 +339,7 @@ int nasal_hash::get_mem_address(std::string key)
     else
     {
         int mem_addr=nasal_vm.mem_alloc();
-        int val_addr=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(val_addr).set_type(vm_nil);
+        int val_addr=nasal_vm.gc_alloc(vm_nil);
         nasal_vm.mem_init(mem_addr,val_addr);
         elems[key]=mem_addr;
         ret_mem_addr=mem_addr;
@@ -376,13 +374,11 @@ bool nasal_hash::check_contain(std::string key)
 }
 int nasal_hash::get_keys()
 {
-    int ret_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(ret_addr).set_type(vm_vector);
+    int ret_addr=nasal_vm.gc_alloc(vm_vector);
     nasal_vector& ref_vec=nasal_vm.gc_get(ret_addr).get_vector();
     for(std::map<std::string,int>::iterator iter=elems.begin();iter!=elems.end();++iter)
     {
-        int str_addr=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(str_addr).set_type(vm_string);
+        int str_addr=nasal_vm.gc_alloc(vm_string);
         nasal_vm.gc_get(str_addr).set_string(iter->first);
         ref_vec.add_elem(str_addr);
     }
@@ -432,8 +428,7 @@ void nasal_function::set_closure_addr(int value_address)
 {
     if(closure_addr>=0)
         nasal_vm.del_reference(closure_addr);
-    int new_closure=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_closure).set_type(vm_closure);
+    int new_closure=nasal_vm.gc_alloc(vm_closure);
     nasal_vm.gc_get(new_closure).get_closure().set_closure(nasal_vm.gc_get(value_address).get_closure());
     closure_addr=new_closure;
     return;
@@ -598,9 +593,13 @@ void nasal_scalar::clear()
     }
     return;
 }
-bool nasal_scalar::set_type(int nasal_scalar_type)
+void nasal_scalar::set_type(int nasal_scalar_type)
 {
-    bool ret=true;
+    if(this->scalar_ptr)
+    {
+        std::cout<<">> [vm] scalar_ptr is in use.\n";
+        return;
+    }
     this->type=nasal_scalar_type;
     switch(nasal_scalar_type)
     {
@@ -615,10 +614,9 @@ bool nasal_scalar::set_type(int nasal_scalar_type)
             std::cout<<">> [vm] error scalar type: "<<nasal_scalar_type<<".\n";
             this->type=vm_nil;
             this->scalar_ptr=(void*)NULL;
-            ret=false;
             break;
     }
-    return ret;
+    return;
 }
 void nasal_scalar::set_number(double num)
 {
@@ -698,8 +696,7 @@ int nasal_scalar::nasal_scalar_add(int a_scalar_addr,int b_scalar_addr)
     else if(b_ref.type==vm_string)
         b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
 
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number(a_num+b_num);
     return new_value_address;
 }
@@ -724,8 +721,7 @@ int nasal_scalar::nasal_scalar_sub(int a_scalar_addr,int b_scalar_addr)
     else if(b_ref.type==vm_string)
         b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
     
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number(a_num-b_num);
     return new_value_address;
 }
@@ -750,8 +746,7 @@ int nasal_scalar::nasal_scalar_mult(int a_scalar_addr,int b_scalar_addr)
     else if(b_ref.type==vm_string)
         b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
 
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number(a_num*b_num);
     return new_value_address;
 }
@@ -776,8 +771,7 @@ int nasal_scalar::nasal_scalar_div(int a_scalar_addr,int b_scalar_addr)
     else if(b_ref.type==vm_string)
         b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
 
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number(a_num/b_num);
     return new_value_address;
 }
@@ -799,8 +793,7 @@ int nasal_scalar::nasal_scalar_link(int a_scalar_addr,int b_scalar_addr)
     std::string b_str;
     a_str=(a_ref.type==vm_number)? trans_number_to_string(*(double*)a_ref.scalar_ptr):*(std::string*)a_ref.scalar_ptr;
     b_str=(b_ref.type==vm_number)? trans_number_to_string(*(double*)b_ref.scalar_ptr):*(std::string*)b_ref.scalar_ptr;
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_string);
+    int new_value_address=nasal_vm.gc_alloc(vm_string);
     nasal_vm.gc_get(new_value_address).set_string(a_str+b_str);
     return new_value_address;
 }
@@ -819,8 +812,7 @@ int nasal_scalar::nasal_scalar_unary_sub(int a_scalar_addr)
     else if(a_ref.type==vm_string)
         a_num=trans_string_to_number(*(std::string*)a_ref.scalar_ptr);
 
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number(-a_num);
     return new_value_address;
 }
@@ -835,15 +827,13 @@ int nasal_scalar::nasal_scalar_unary_not(int a_scalar_addr)
     int new_value_address=-1;
     if(a_ref.type==vm_nil)
     {
-        new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number(1);
     }
     else if(a_ref.type==vm_number)
     {
         double number=(double)(*(double*)(a_ref.scalar_ptr)==0);
-        new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number(number);
     }
     else if(a_ref.type==vm_string)
@@ -851,14 +841,12 @@ int nasal_scalar::nasal_scalar_unary_not(int a_scalar_addr)
         double number=trans_string_to_number(*(std::string*)a_ref.scalar_ptr);
         if(std::isnan(number))
         {
-            new_value_address=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(new_value_address).set_type(vm_number);
+            new_value_address=nasal_vm.gc_alloc(vm_number);
             nasal_vm.gc_get(new_value_address).set_number(!(*(std::string*)a_ref.scalar_ptr).length());
         }
         else
         {
-            new_value_address=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(new_value_address).set_type(vm_number);
+            new_value_address=nasal_vm.gc_alloc(vm_number);
             nasal_vm.gc_get(new_value_address).set_number((double)(number==0));
         }
     }
@@ -875,8 +863,7 @@ int nasal_scalar::nasal_scalar_cmp_equal(int a_scalar_addr,int b_scalar_addr)
     }
     if(a_scalar_addr==b_scalar_addr)
     {
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number(1);
         return new_value_address;
     }
@@ -884,8 +871,7 @@ int nasal_scalar::nasal_scalar_cmp_equal(int a_scalar_addr,int b_scalar_addr)
     nasal_scalar& b_ref=nasal_vm.gc_get(b_scalar_addr);
     if(a_ref.type==vm_nil && b_ref.type==vm_nil)
     {
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number(1);
         return new_value_address;
     }
@@ -895,8 +881,7 @@ int nasal_scalar::nasal_scalar_cmp_equal(int a_scalar_addr,int b_scalar_addr)
         {
             std::string astr=*(std::string*)a_ref.scalar_ptr;
             std::string bstr=*(std::string*)b_ref.scalar_ptr;
-            int new_value_address=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(new_value_address).set_type(vm_number);
+            int new_value_address=nasal_vm.gc_alloc(vm_number);
             nasal_vm.gc_get(new_value_address).set_number((double)(astr==bstr));
             return new_value_address;
         }
@@ -911,15 +896,13 @@ int nasal_scalar::nasal_scalar_cmp_equal(int a_scalar_addr,int b_scalar_addr)
         else
             b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
         
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number((double)(a_num==b_num));
         return new_value_address;
     }
     else
     {
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number(0);
         return new_value_address;
     }
@@ -934,8 +917,7 @@ int nasal_scalar::nasal_scalar_cmp_not_equal(int a_scalar_addr,int b_scalar_addr
     }
     if(a_scalar_addr==b_scalar_addr)
     {
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number(0);
         return new_value_address;
     }
@@ -943,8 +925,7 @@ int nasal_scalar::nasal_scalar_cmp_not_equal(int a_scalar_addr,int b_scalar_addr
     nasal_scalar& b_ref=nasal_vm.gc_get(b_scalar_addr);
     if(a_ref.type==vm_nil && b_ref.type==vm_nil)
     {
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number(0);
         return new_value_address;
     }
@@ -954,8 +935,7 @@ int nasal_scalar::nasal_scalar_cmp_not_equal(int a_scalar_addr,int b_scalar_addr
         {
             std::string astr=*(std::string*)a_ref.scalar_ptr;
             std::string bstr=*(std::string*)b_ref.scalar_ptr;
-            int new_value_address=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(new_value_address).set_type(vm_number);
+            int new_value_address=nasal_vm.gc_alloc(vm_number);
             nasal_vm.gc_get(new_value_address).set_number((double)(astr!=bstr));
             return new_value_address;
         }
@@ -970,15 +950,13 @@ int nasal_scalar::nasal_scalar_cmp_not_equal(int a_scalar_addr,int b_scalar_addr
         else
             b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
 
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number((double)(a_num!=b_num));
         return new_value_address;
     }
     else
     {
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number(1);
         return new_value_address;
     }
@@ -998,8 +976,7 @@ int nasal_scalar::nasal_scalar_cmp_less(int a_scalar_addr,int b_scalar_addr)
     {
         std::string a_str=*(std::string*)a_ref.scalar_ptr;
         std::string b_str=*(std::string*)b_ref.scalar_ptr;
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number((double)(a_str<b_str));
         return new_value_address;
     }
@@ -1014,8 +991,7 @@ int nasal_scalar::nasal_scalar_cmp_less(int a_scalar_addr,int b_scalar_addr)
     else if(b_ref.type==vm_string)
         b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
 
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number((double)(a_num<b_num));
     return new_value_address;
 }
@@ -1033,8 +1009,7 @@ int nasal_scalar::nasal_scalar_cmp_greater(int a_scalar_addr,int b_scalar_addr)
     {
         std::string a_str=*(std::string*)a_ref.scalar_ptr;
         std::string b_str=*(std::string*)b_ref.scalar_ptr;
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number((double)(a_str>b_str));
         return new_value_address;
     }
@@ -1049,8 +1024,7 @@ int nasal_scalar::nasal_scalar_cmp_greater(int a_scalar_addr,int b_scalar_addr)
     else if(b_ref.type==vm_string)
         b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
     
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number((double)(a_num>b_num));
     return new_value_address;
 }
@@ -1068,8 +1042,7 @@ int nasal_scalar::nasal_scalar_cmp_less_or_equal(int a_scalar_addr,int b_scalar_
     {
         std::string a_str=*(std::string*)a_ref.scalar_ptr;
         std::string b_str=*(std::string*)b_ref.scalar_ptr;
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number((double)(a_str<=b_str));
         return new_value_address;
     }
@@ -1084,8 +1057,7 @@ int nasal_scalar::nasal_scalar_cmp_less_or_equal(int a_scalar_addr,int b_scalar_
     else if(b_ref.type==vm_string)
         b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
     
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number((double)(a_num<=b_num));
     return new_value_address;
 }
@@ -1103,8 +1075,7 @@ int nasal_scalar::nasal_scalar_cmp_greater_or_equal(int a_scalar_addr,int b_scal
     {
         std::string a_str=*(std::string*)a_ref.scalar_ptr;
         std::string b_str=*(std::string*)b_ref.scalar_ptr;
-        int new_value_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_value_address).set_type(vm_number);
+        int new_value_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(new_value_address).set_number((double)(a_str>=b_str));
         return new_value_address;
     }
@@ -1119,8 +1090,7 @@ int nasal_scalar::nasal_scalar_cmp_greater_or_equal(int a_scalar_addr,int b_scal
     else if(b_ref.type==vm_string)
         b_num=trans_string_to_number(*(std::string*)b_ref.scalar_ptr);
     
-    int new_value_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_value_address).set_type(vm_number);
+    int new_value_address=nasal_vm.gc_alloc(vm_number);
     nasal_vm.gc_get(new_value_address).set_number((double)(a_num>=b_num));
     return new_value_address;
 }
@@ -1216,19 +1186,23 @@ void nasal_virtual_machine::clear()
     error_info_output_switch=true;
     return;
 }
-int nasal_virtual_machine::gc_alloc()
+int nasal_virtual_machine::gc_alloc(int val_type)
 {
     if(garbage_collector_free_space.empty())
     {
         gc_unit* new_block=new gc_unit[256];
         garbage_collector_memory.push_back(new_block);
         int mem_size=garbage_collector_memory.size();
-        for(int i=((mem_size-1)<<8);i<(mem_size<<8);++i)
+        int begin=((mem_size-1)<<8);
+        int end=(mem_size<<8);
+        for(int i=begin;i<end;++i)
             garbage_collector_free_space.push(i);
     }
     int ret=garbage_collector_free_space.front();
-    garbage_collector_memory[ret>>8][ret&0xff].collected=false;
-    garbage_collector_memory[ret>>8][ret&0xff].ref_cnt=1;
+    gc_unit& unit_ref=garbage_collector_memory[ret>>8][ret&0xff];
+    unit_ref.collected=false;
+    unit_ref.ref_cnt=1;
+    unit_ref.elem.set_type(val_type);
     garbage_collector_free_space.pop();
     return ret;
 }
@@ -1278,19 +1252,6 @@ void nasal_virtual_machine::del_reference(int value_address)
     }
     return;
 }
-int nasal_virtual_machine::get_refcnt(int value_address)
-{
-    int blk_num=(value_address>>8);
-    int blk_plc=(value_address&0xff);
-    if(0<=value_address && value_address<(garbage_collector_memory.size()<<8) && !garbage_collector_memory[blk_num][blk_plc].collected)
-        return garbage_collector_memory[blk_num][blk_plc].ref_cnt;
-    else
-    {
-        if(error_info_output_switch)
-            std::cout<<">> [vm] get_refcnt:unexpected memory \'"<<value_address<<"\'.\n";
-    }
-    return -1;
-}
 int nasal_virtual_machine::mem_alloc()
 {
     if(memory_manager_free_space.empty())
diff --git a/nasal_runtime.h b/nasal_runtime.h
index 0e0b5ec..de39234 100644
--- a/nasal_runtime.h
+++ b/nasal_runtime.h
@@ -190,8 +190,7 @@ void nasal_runtime::run()
     this->error=0;
     this->function_returned_address=-1;
 
-    this->global_scope_address=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(global_scope_address).set_type(vm_closure);
+    this->global_scope_address=nasal_vm.gc_alloc(vm_closure);
     nasal_vm.gc_get(global_scope_address).get_closure().add_scope();
 
     time_t begin_time=std::time(NULL);
@@ -211,8 +210,7 @@ void nasal_runtime::run()
 // private functions
 int nasal_runtime::vector_generation(nasal_ast& node,int local_scope_addr)
 {
-    int new_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_addr).set_type(vm_vector);
+    int new_addr=nasal_vm.gc_alloc(vm_vector);
     nasal_vector& ref_of_this_vector=nasal_vm.gc_get(new_addr).get_vector();
 
     int node_children_size=node.get_children().size();
@@ -222,8 +220,7 @@ int nasal_runtime::vector_generation(nasal_ast& node,int local_scope_addr)
 }
 int nasal_runtime::hash_generation(nasal_ast& node,int local_scope_addr)
 {
-    int new_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_addr).set_type(vm_hash);
+    int new_addr=nasal_vm.gc_alloc(vm_hash);
     nasal_hash& ref_of_this_hash=nasal_vm.gc_get(new_addr).get_hash();
     int node_children_size=node.get_children().size();
     for(int i=0;i<node_children_size;++i)
@@ -236,8 +233,7 @@ int nasal_runtime::hash_generation(nasal_ast& node,int local_scope_addr)
 }
 int nasal_runtime::function_generation(nasal_ast& node,int local_scope_addr)
 {
-    int new_addr=nasal_vm.gc_alloc();
-    nasal_vm.gc_get(new_addr).set_type(vm_function);
+    int new_addr=nasal_vm.gc_alloc(vm_function);
     nasal_function& ref_of_this_function=nasal_vm.gc_get(new_addr).get_func();
 
     ref_of_this_function.set_arguments(node.get_children()[0]);
@@ -247,8 +243,7 @@ int nasal_runtime::function_generation(nasal_ast& node,int local_scope_addr)
         ref_of_this_function.set_closure_addr(local_scope_addr);
     else
     {
-        int new_closure=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(new_closure).set_type(vm_closure);
+        int new_closure=nasal_vm.gc_alloc(vm_closure);
         ref_of_this_function.set_closure_addr(new_closure);
         nasal_vm.del_reference(new_closure);
     }
@@ -293,8 +288,7 @@ int nasal_runtime::block_progress(nasal_ast& node,int local_scope_addr,bool allo
     // if local_scope does not exist,create a new one.
     if(local_scope_addr<0)
     {
-        local_scope_addr=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(local_scope_addr).set_type(vm_closure);
+        local_scope_addr=nasal_vm.gc_alloc(vm_closure);
         nasal_vm.gc_get(local_scope_addr).get_closure().add_scope();
     }
     else
@@ -332,10 +326,7 @@ int nasal_runtime::block_progress(nasal_ast& node,int local_scope_addr,bool allo
                     if(tmp_node.get_children().size())
                         function_returned_address=calculation(tmp_node.get_children()[0],local_scope_addr);
                     else
-                    {
-                        function_returned_address=nasal_vm.gc_alloc();
-                        nasal_vm.gc_get(function_returned_address).set_type(vm_nil);
-                    }
+                        function_returned_address=nasal_vm.gc_alloc(vm_nil);
                 } 
                 else
                     die(tmp_node.get_line(),"cannot use return here");
@@ -402,8 +393,7 @@ int nasal_runtime::loop_progress(nasal_ast& node,int local_scope_addr,bool allow
         int while_local_scope_addr=local_scope_addr;
         if(while_local_scope_addr<0)
         {
-            while_local_scope_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(while_local_scope_addr).set_type(vm_closure);
+            while_local_scope_addr=nasal_vm.gc_alloc(vm_closure);
             nasal_vm.gc_get(while_local_scope_addr).get_closure().add_scope();
         }
         else
@@ -444,8 +434,7 @@ int nasal_runtime::loop_progress(nasal_ast& node,int local_scope_addr,bool allow
         int forei_local_scope_addr=local_scope_addr;
         if(forei_local_scope_addr<0)
         {
-            forei_local_scope_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(forei_local_scope_addr).set_type(vm_closure);
+            forei_local_scope_addr=nasal_vm.gc_alloc(vm_closure);
             nasal_vm.gc_get(forei_local_scope_addr).get_closure().add_scope();
         }
         else
@@ -457,8 +446,7 @@ int nasal_runtime::loop_progress(nasal_ast& node,int local_scope_addr,bool allow
         int mem_addr=-1;
         if(iter_node.get_type()==ast_new_iter)
         {
-            int new_value_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(new_value_addr).set_type(vm_nil);
+            int new_value_addr=nasal_vm.gc_alloc(vm_nil);
             std::string val_name=iter_node.get_children()[0].get_str();
             nasal_vm.gc_get(forei_local_scope_addr).get_closure().add_new_value(val_name,new_value_addr);
             mem_addr=nasal_vm.gc_get(forei_local_scope_addr).get_closure().get_mem_address(val_name);
@@ -477,8 +465,7 @@ int nasal_runtime::loop_progress(nasal_ast& node,int local_scope_addr,bool allow
             // update iterator
             if(loop_type==ast_forindex)
             {
-                int new_iter_val_addr=nasal_vm.gc_alloc();
-                nasal_vm.gc_get(new_iter_val_addr).set_type(vm_number);
+                int new_iter_val_addr=nasal_vm.gc_alloc(vm_number);
                 nasal_vm.gc_get(new_iter_val_addr).set_number((double)i);
                 nasal_vm.mem_change(mem_addr,new_iter_val_addr);
             }
@@ -507,8 +494,7 @@ int nasal_runtime::loop_progress(nasal_ast& node,int local_scope_addr,bool allow
         int for_local_scope_addr=local_scope_addr;
         if(for_local_scope_addr<0)
         {
-            for_local_scope_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(for_local_scope_addr).set_type(vm_closure);
+            for_local_scope_addr=nasal_vm.gc_alloc(vm_closure);
             nasal_vm.gc_get(for_local_scope_addr).get_closure().add_scope();
         }
         else
@@ -783,8 +769,7 @@ int nasal_runtime::call_vector(nasal_ast& node,int base_value_addr,int local_sco
         }
         else
         {
-            return_value_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(return_value_addr).set_type(vm_vector);
+            return_value_addr=nasal_vm.gc_alloc(vm_vector);
             nasal_vector& return_vector=nasal_vm.gc_get(return_value_addr).get_vector();
             int vec_size=called_value_addrs.size();
             for(int i=0;i<vec_size;++i)
@@ -854,8 +839,7 @@ int nasal_runtime::call_vector(nasal_ast& node,int base_value_addr,int local_sco
         else
             index_num=(int)nasal_vm.gc_get(index_value_addr).get_number();
         nasal_vm.del_reference(index_value_addr);
-        return_value_addr=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(return_value_addr).set_type(vm_number);
+        return_value_addr=nasal_vm.gc_alloc(vm_number);
         std::string str=nasal_vm.gc_get(base_value_addr).get_string();
         int str_size=str.length();
         if(index_num>=str_size || index_num<-str_size)
@@ -915,8 +899,7 @@ int nasal_runtime::call_function(nasal_ast& node,std::string func_name,int base_
         else if(argument_format.get_children().size() && argument_format.get_children()[0].get_type()==ast_dynamic_id)
         {
             // load null dynamic-id
-            int vector_value_addr=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(vector_value_addr).set_type(vm_vector);
+            int vector_value_addr=nasal_vm.gc_alloc(vm_vector);
             run_closure.add_new_value(argument_format.get_children()[0].get_str(),vector_value_addr);
         }
         else if(argument_format.get_children().size() && argument_format.get_children()[0].get_type()==ast_default_arg)
@@ -989,8 +972,7 @@ int nasal_runtime::call_function(nasal_ast& node,std::string func_name,int base_
             if(!args_usage_table[dyn_str])
             {
                 args_usage_table[dyn_str]=true;
-                int vector_value_addr=nasal_vm.gc_alloc();
-                nasal_vm.gc_get(vector_value_addr).set_type(vm_vector);
+                int vector_value_addr=nasal_vm.gc_alloc(vm_vector);
                 run_closure.add_new_value(dyn_str,vector_value_addr);
             }
         }
@@ -1026,8 +1008,7 @@ int nasal_runtime::call_function(nasal_ast& node,std::string func_name,int base_
             {
                 if(tmp_node.get_type()==ast_dynamic_id)
                 {
-                    int vector_value_addr=nasal_vm.gc_alloc();
-                    nasal_vm.gc_get(vector_value_addr).set_type(vm_vector);
+                    int vector_value_addr=nasal_vm.gc_alloc(vm_vector);
                     nasal_vector& ref_vec=nasal_vm.gc_get(vector_value_addr).get_vector();
                     for(int j=i;j<size;++j)
                         ref_vec.add_elem(args[j]);
@@ -1073,10 +1054,7 @@ int nasal_runtime::call_function(nasal_ast& node,std::string func_name,int base_
         function_returned_address=-1;
     }
     else
-    {
-        ret_value_addr=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(ret_value_addr).set_type(vm_nil);
-    }
+        ret_value_addr=nasal_vm.gc_alloc(vm_nil);
     return ret_value_addr;
 }
 int nasal_runtime::call_builtin_function(std::string val_name,int local_scope_addr)
@@ -1229,25 +1207,19 @@ int nasal_runtime::calculation(nasal_ast& node,int local_scope_addr)
     int calculation_type=node.get_type();
     if(calculation_type==ast_null)
     {
-        ret_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(ret_address).set_type(vm_number);
+        ret_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(ret_address).set_number(1);
     }
     else if(calculation_type==ast_nil)
-    {
-        ret_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(ret_address).set_type(vm_nil);
-    }
+        ret_address=nasal_vm.gc_alloc(vm_nil);
     else if(calculation_type==ast_number)
     {
-        ret_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(ret_address).set_type(vm_number);
+        ret_address=nasal_vm.gc_alloc(vm_number);
         nasal_vm.gc_get(ret_address).set_number(node.get_num());
     }
     else if(calculation_type==ast_string)
     {
-        ret_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(ret_address).set_type(vm_string);
+        ret_address=nasal_vm.gc_alloc(vm_string);
         nasal_vm.gc_get(ret_address).set_string(node.get_str());
     }
     else if(calculation_type==ast_identifier)
@@ -1259,8 +1231,7 @@ int nasal_runtime::calculation(nasal_ast& node,int local_scope_addr)
         if(ret_address<0)
         {
             die(node.get_line(),"cannot find \""+node.get_str()+"\"");
-            ret_address=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(ret_address).set_type(vm_nil);
+            ret_address=nasal_vm.gc_alloc(vm_nil);
         }
         nasal_vm.add_reference(ret_address);
     }
@@ -1377,8 +1348,7 @@ int nasal_runtime::calculation(nasal_ast& node,int local_scope_addr)
         if(!check_condition(left_gc_addr))
         {
             nasal_vm.del_reference(left_gc_addr);
-            ret_address=nasal_vm.gc_alloc();
-            nasal_vm.gc_get(ret_address).set_type(vm_number);
+            ret_address=nasal_vm.gc_alloc(vm_number);
             nasal_vm.gc_get(ret_address).set_number(0);
         }
         else
@@ -1388,8 +1358,7 @@ int nasal_runtime::calculation(nasal_ast& node,int local_scope_addr)
             {
                 nasal_vm.del_reference(left_gc_addr);
                 nasal_vm.del_reference(right_gc_addr);
-                ret_address=nasal_vm.gc_alloc();
-                nasal_vm.gc_get(ret_address).set_type(vm_number);
+                ret_address=nasal_vm.gc_alloc(vm_number);
                 nasal_vm.gc_get(ret_address).set_number(0);
             }
             else
@@ -1416,8 +1385,7 @@ int nasal_runtime::calculation(nasal_ast& node,int local_scope_addr)
             {
                 nasal_vm.del_reference(left_gc_addr);
                 nasal_vm.del_reference(right_gc_addr);
-                ret_address=nasal_vm.gc_alloc();
-                nasal_vm.gc_get(ret_address).set_type(vm_number);
+                ret_address=nasal_vm.gc_alloc(vm_number);
                 nasal_vm.gc_get(ret_address).set_number(0);
             }
         }
@@ -1512,8 +1480,7 @@ int nasal_runtime::calculation(nasal_ast& node,int local_scope_addr)
     else
     {
         die(node.get_line(),"cannot calculate expression: "+ast_str(node.get_type()));
-        ret_address=nasal_vm.gc_alloc();
-        nasal_vm.gc_get(ret_address).set_type(vm_nil);
+        ret_address=nasal_vm.gc_alloc(vm_nil);
     }
     return ret_address;
 }