diff --git a/src/code_defs.h b/src/code_defs.h
index e569e83..3b5636e 100755
--- a/src/code_defs.h
+++ b/src/code_defs.h
@@ -57,6 +57,7 @@ struct Statement {
   i32 is_const; // Statement is constant, != is a constant - TODO : implem
   void **children;
   i32 child_n;
+  void *parent;
   union {
     Value cons;
     struct {
diff --git a/src/hash.c b/src/hash.c
index 13f3beb..ea25447 100755
--- a/src/hash.c
+++ b/src/hash.c
@@ -1,3 +1,52 @@
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+
+#include "types.h"
+#include "hash.h"
+#include "config.h"
+
+int heap_hashmap(HashMap *map, i32 size){
+  if(size < 32)
+    return 1;
+  map->curr_len = size;
+  map->buffer = malloc(sizeof(MapItem)*size);
+  map->bit_free = malloc(sizeof(u32)*size/32);
+
+  if(!map->buffer || !map->bit_free)
+    return 1;
+
+  memset(map->bit_free, 0, sizeof(u32)*size/32);
+  memset(map->buffer, 0, sizeof(MapItem)*size);
+  for(int i = 0; i < size; i++)
+    map->buffer[i].id = -1;
+
+  return 0;
+}
+
+void free_hashmap(HashMap *map){
+  free(map->buffer);
+  free(map->bit_free);
+}
+
+// ~djb2
+i32 hash(i32 max, char *str){
+  if(!str)
+    return HASH_NULL; 
+  u32 hsh = 5281;
+  char ch = str[0];
+  for(int i = 1; i < 32 && ch; i++){
+    hsh = (hsh << 5) ^ ch;
+    ch = str[i];
+  }
+  hsh %= max;
+  #if DEBUG == 2
+  assert(hsh < HASH_NULL); 
+  #endif
+  return hsh;
+}
+
+i32 get_bit(u32 *bitmap, i32 pos){
   return (bitmap[pos/32] >> (pos%32)) & 1;
 }
 
@@ -84,3 +133,18 @@ void hashmap_remove(HashMap *map, char *str){
   // (Literally 1984) 
   memset(ret, 0, sizeof(MapItem));
 }
+
+int cmp_mapitem_id(const void *_a, const void *_b){
+  const MapItem *a = _a;
+  const MapItem *b = _b;
+  return b->id - a->id;
+}
+
+void hashmap_remove_id(HashMap *map, i32 id){
+  MapItem tmp = {.id = id};
+  MapItem *ret = bsearch(&tmp, map->buffer, map->curr_len, sizeof(MapItem),
+                          cmp_mapitem_id);
+  if(!ret)
+    return;
+  memset(ret, 0, sizeof(MapItem));
+}
diff --git a/src/hash.h b/src/hash.h
index 3f9e959..b26c0bf 100755
--- a/src/hash.h
+++ b/src/hash.h
@@ -46,3 +46,5 @@ MapItem *hashmap_insert(HashMap *map, char *str);
 MapItem *hashmap_get(HashMap *map, char *str);
 
 void hashmap_remove(HashMap *map, char *str);
+
+void hashmap_remove_id(HashMap *map, i32 id);