diff --git a/base.cpp b/base.cpp
index 786deac..5a41468 100644
--- a/base.cpp
+++ b/base.cpp
@@ -555,8 +555,10 @@ arena_clear(Arena *arena){
   arena_pop_pos(arena, 0);
 }
 
+#define arena_push_array(a, T, size,...) (T *)arena_push_size(a, sizeof(T)*(size),##__VA_ARGS__)
+#define arena_push_type(a, T, ...) arena_push_array(a, T, 1,##__VA_ARGS__)
 function void *
-arena_push_size(Arena *a, size_t size){
+arena_push_size(Arena *a, size_t size, Alloc_Flag flags = AF_None){
   size_t generous_size = size + a->alignment;
   if(a->len+generous_size>a->memory.commit){
     if(a->memory.reserve == 0){
@@ -570,6 +572,11 @@ arena_push_size(Arena *a, size_t size){
   assert(a->memory.reserve > a->len + size);
   void *result = (U8*)a->memory.data + a->len;
   a->len += size;
+
+  if(flags & AF_ZeroMemory){
+    memory_zero(result, size);
+  }
+
   return result;
 }
 
@@ -911,7 +918,7 @@ struct Map_Key_Value{
 };
 
 struct Map{
-  Allocator *allocator;
+  Arena *allocator;
   Map_Key_Value *data;
   S64 len;
   S64 cap;
@@ -923,10 +930,10 @@ map_grow(Map *map, S64 new_size){
   new_size = max((S64)16, new_size);
   assert(new_size > map->cap);
   assert(is_pow2(new_size));
-  if(map->cap == 0 && map->allocator == 0) map->allocator = imp_get();
+  assert(map->allocator);
 
   Map new_map       = {};
-  new_map.data      = exp_alloc_array(map->allocator, Map_Key_Value, new_size, AF_ZeroMemory);
+  new_map.data      = arena_push_array(map->allocator, Map_Key_Value, new_size, AF_ZeroMemory);
   new_map.cap       = new_size;
   new_map.allocator = map->allocator;
 
@@ -935,12 +942,12 @@ map_grow(Map *map, S64 new_size){
       map_insert(&new_map, map->data[i].key, map->data[i].value);
     }
   }
-  if(map->data) exp_free(map->allocator, map->data);
+  // if(map->data) exp_free(map->allocator, map->data);
   *map = new_map;
 }
 
 function Map
-map_make(Allocator *a, S64 size){
+map_make(Arena *a, S64 size){
   Map result = {a};
   map_grow(&result, size);
   return result;
@@ -1057,14 +1064,14 @@ map_test(){
 // String intern
 //-----------------------------------------------------------------------------
 struct Intern_Table{
-  Allocator *string_allocator;
+  Arena *string_allocator;
   Map map;
   U8 *first_keyword;
   U8 *last_keyword;
 };
 
 function Intern_Table
-intern_table_make(Allocator *string_allocator, Allocator *map_allocator, S64 initial_size = 32){
+intern_table_make(Arena *string_allocator, Arena *map_allocator, S64 initial_size = 32){
   Intern_Table result     = {};
   result.map              = map_make(map_allocator, initial_size);
   result.string_allocator = string_allocator;
@@ -1341,7 +1348,7 @@ T pop(List<T> *list){
 template<class T>
 T *merge(Arena *arena, List<T> *list){
   int len = length(list);
-  T *result = exp_alloc_array(arena, T, len);
+  T *result = arena_push_array(arena, T, len);
 
   int i = 0;
   For_Linked_List(list->first){
diff --git a/base_string.cpp b/base_string.cpp
index f36986c..5afda66 100644
--- a/base_string.cpp
+++ b/base_string.cpp
@@ -76,8 +76,8 @@ operator==(String a, String b){
 }
 
 function String
-string_copy(Allocator *a, String string){
-  U8 *copy = exp_alloc_array(a, U8, string.len+1);
+string_copy(Arena *a, String string){
+  U8 *copy = arena_push_array(a, U8, string.len+1);
   memory_copy(copy, string.str, string.len);
   copy[string.len] = 0;
   return String{copy, string.len};
@@ -368,7 +368,7 @@ string_trim_end(String string) {
 }
 
 function String
-string_to_lower_case(Allocator *arena, String s) {
+string_to_lower_case(Arena *arena, String s) {
   String copy = string_copy(arena, s);
   for (U64 i = 0; i < copy.len; i++) {
     copy.str[i] = to_lower_case(copy.str[i]);
@@ -377,7 +377,7 @@ string_to_lower_case(Allocator *arena, String s) {
 }
 
 function String
-string_to_upper_case(Allocator *arena, String s) {
+string_to_upper_case(Arena *arena, String s) {
   String copy = string_copy(arena, s);
   for (U64 i = 0; i < copy.len; i++) {
     copy.str[i] = to_upper_case(copy.str[i]);
diff --git a/core_ast.cpp b/core_ast.cpp
index cd74d2f..15c9527 100644
--- a/core_ast.cpp
+++ b/core_ast.cpp
@@ -293,7 +293,7 @@ struct Ast_Decl: Ast{
 // AST Constructors beginning with expressions
 //-----------------------------------------------------------------------------
 #define AST_NEW(T,ikind,ipos,iflags)                                   \
-  Ast_##T *result = exp_alloc_type(pctx->perm, Ast_##T, AF_ZeroMemory);\
+  Ast_##T *result = arena_push_type(pctx->perm, Ast_##T, AF_ZeroMemory);\
   result->flags   = iflags;                                            \
   result->kind    = AST_##ikind;                                       \
   result->parent_scope = pctx->currently_parsed_scope;                 \
@@ -303,7 +303,7 @@ struct Ast_Decl: Ast{
 #define ast_new(T,kind,pos,flags) (T *)_ast_new(sizeof(T), kind, pos, flags)
 function Ast *
 _ast_new(size_t size, Ast_Kind kind, Token *pos, Ast_Flag flags = 0){
-  Ast *result = (Ast *)exp_alloc(pctx->perm, size, AF_ZeroMemory);
+  Ast *result = (Ast *)arena_push_size(pctx->perm, size, AF_ZeroMemory);
   result->flags   = flags;
   result->kind    = kind;
   result->parent_scope = pctx->currently_parsed_scope;
@@ -487,7 +487,7 @@ finalize_decl_scope(Ast_Scope *scope){
 }
 
 function Ast_Scope *
-begin_stmt_scope(Allocator *scratch, Token *pos){
+begin_stmt_scope(Arena *scratch, Token *pos){
   AST_NEW(Scope, SCOPE, pos, AST_STMT);
   result->stmts = {scratch};
   result->file  = pctx->currently_parsed_file;
diff --git a/core_codegen_c_language.cpp b/core_codegen_c_language.cpp
index fa83ef2..4694544 100644
--- a/core_codegen_c_language.cpp
+++ b/core_codegen_c_language.cpp
@@ -34,7 +34,7 @@ gen_last_line(){
 }
 
 function String
-string_scope_name(Allocator *a, Ast_Scope *scope){
+string_scope_name(Arena *a, Ast_Scope *scope){
   String string = {};
   if(scope->parent_scope) string = string_scope_name(a, scope->parent_scope);
   assert_message(scope->scope_id != 0, "Scope id is equal to 0 which is invalid, scope didn't initialize id");
@@ -50,8 +50,8 @@ gen_scope_name(Ast_Scope *scope){
 }
 
 function String
-unique_name(Allocator *allocator, Ast *ast){
-  Scratch scratch;
+unique_name(Arena *allocator, Ast *ast){
+  Scratch scratch(allocator);
   String result = string_scope_name(scratch, ast->parent_scope);
   assert(result.len);
   result = string_fmt(allocator, "%Q%d", result, ast->pos->line);
@@ -85,7 +85,7 @@ get_ctype_name_for_type(Ast_Type *type){
 }
 
 function String
-string_simple_decl_prefix(Allocator *a, Ast_Type *ast){
+string_simple_decl_prefix(Arena *a, Ast_Type *ast){
   switch(ast->kind){
     case TYPE_POINTER:{
       String string = string_simple_decl_prefix(a, ast->base);
@@ -122,7 +122,7 @@ string_simple_decl_prefix(Allocator *a, Ast_Type *ast){
 }
 
 function String
-string_simple_decl_postfix(Allocator *a, Ast_Type *ast){
+string_simple_decl_postfix(Arena *a, Ast_Type *ast){
   switch(ast->kind){
     case TYPE_POINTER:
       return string_simple_decl_postfix(a, ast->base);
@@ -141,7 +141,7 @@ string_simple_decl_postfix(Allocator *a, Ast_Type *ast){
 }
 
 function String
-string_simple_decl(Allocator *a, Ast_Type *ast, Intern_String name = {}){
+string_simple_decl(Arena *a, Ast_Type *ast, Intern_String name = {}){
   if(ast->kind == TYPE_LAMBDA) {
     String prefix = string_simple_decl_prefix(a, ast->func.ret);
     String string = string_fmt(a, "%Q(*%Q)(", prefix, name);
@@ -173,7 +173,7 @@ gen_simple_decl(Ast_Type *ast, Intern_String name = {}){
 }
 
 function String
-gen_string_simple_decl(Allocator *a, Ast_Type *ast, String name){
+gen_string_simple_decl(Arena *a, Ast_Type *ast, String name){
   Scratch scratch;
   String string = string_simple_decl(scratch, ast, pctx->intern(name));
   String result = string_copy(a, string);
diff --git a/core_compiler.cpp b/core_compiler.cpp
index 66514f6..06c0338 100644
--- a/core_compiler.cpp
+++ b/core_compiler.cpp
@@ -1,6 +1,6 @@
 
 function void
-lex_init(Allocator *token_string_arena, Allocator *map_allocator, Lexer *l){
+lex_init(Arena *token_string_arena, Arena *map_allocator, Lexer *l){
   l->arena = token_string_arena;
   l->tokens = array_make<Token>(token_string_arena, 4096*4);
   l->interns= intern_table_make(token_string_arena, map_allocator, 2048);
@@ -106,8 +106,8 @@ begin_compilation(){
 
 function void
 destroy_compiler(){
-  exp_free_all(pctx->perm);
-  exp_free_all(&pctx->stage_arena);
+  arena_clear(pctx->perm);
+  arena_clear(&pctx->stage_arena);
 }
 
 function void
diff --git a/core_compiler.h b/core_compiler.h
index 7985260..ff8078f 100644
--- a/core_compiler.h
+++ b/core_compiler.h
@@ -187,7 +187,7 @@ struct Parse_Ctx:Lexer{
 };
 
 function void init_type();
-function void lex_init(Allocator *token_string_arena, Allocator *map_allocator, Lexer *l);
+function void lex_init(Arena *token_string_arena, Arena *map_allocator, Lexer *l);
 function String compile_to_c_code();
 function Ast_Module *ast_module(Token *pos, Intern_String filename);
 function void insert_builtin_types_into_scope(Ast_Scope *p);
diff --git a/core_lexing.cpp b/core_lexing.cpp
index c772b7e..e867a4a 100644
--- a/core_lexing.cpp
+++ b/core_lexing.cpp
@@ -586,7 +586,7 @@ lex__stream(Lexer *lexer){
 }
 
 function Lexer
-lex_make(Allocator *token_string_arena, Allocator *map_allocator){
+lex_make(Arena *token_string_arena, Arena *map_allocator){
   Lexer result  = {};
   lex_init(token_string_arena, map_allocator, &result);
   return result;
@@ -606,7 +606,7 @@ lex_restream(Lexer *lexer, String istream, String file){
 }
 
 function Lexer
-lex_stream(Allocator *token_string_arena, Allocator *map_allocator, String istream, String file){
+lex_stream(Arena *token_string_arena, Arena *map_allocator, String istream, String file){
   Lexer result = lex_make(token_string_arena, map_allocator);
   lex_restream(&result, istream, file);
   return result;
diff --git a/core_typechecking.cpp b/core_typechecking.cpp
index f55a118..a987443 100644
--- a/core_typechecking.cpp
+++ b/core_typechecking.cpp
@@ -20,13 +20,13 @@ operand(Ast_Decl *decl){
   return result;
 }
 
-function Operand
-operand_type(Ast_Type *type){
-  Operand result = {};
-  result.type = type_type;
-  result.is_const = true;
+static Operand
+operand_type(Ast_Type *type) {
+  Operand result   = {};
+  result.type      = type_type;
+  result.is_const  = true;
   result.is_lvalue = false;
-  result.type_val = type;
+  result.type_val  = type;
   return result;
 }
 
diff --git a/os_windows.cpp b/os_windows.cpp
index 02a7791..a854053 100644
--- a/os_windows.cpp
+++ b/os_windows.cpp
@@ -182,7 +182,7 @@ os_does_file_exist(String path){
 }
 
 function Array<OS_File_Info>
-os_list_dir(Allocator *a, String dir, U32 flags = LIST_NO_FLAGS){
+os_list_dir(Arena *a, String dir, U32 flags = LIST_NO_FLAGS){
   Scratch scratch(a);
   Array<String> dirs_to_read = {scratch};
   dirs_to_read.add(dir);