diff --git a/core_compiler_interface.hpp b/core_compiler_interface.hpp
index 1b6c8d7..20de468 100644
--- a/core_compiler_interface.hpp
+++ b/core_compiler_interface.hpp
@@ -342,6 +342,7 @@ enum Ast_Kind : uint32_t {
     AST_ENUM,
     AST_ENUM_MEMBER,
     AST_STRUCT,
+    AST_UNION,
 };
 
 typedef uint32_t Ast_Flag;
diff --git a/core_parsing.cpp b/core_parsing.cpp
index d97b87a..8dbaffb 100644
--- a/core_parsing.cpp
+++ b/core_parsing.cpp
@@ -225,10 +225,9 @@ parse_init_stmt(Ast_Expr *expr) {
 
 CORE_Static Ast_Call *
 parse_expr_call(Ast_Expr *left, Token_Kind close_kind) {
-    Arena *scratch = pctx->scratch;
-    Scratch_Scope __scope(scratch);
+    Scratch_Scope scratch(pctx->scratch);
     Token *pos = token_get();
-    Array<Ast_Call_Item *> exprs = {scratch};
+    Array<Ast_Call_Item *> exprs = {scratch.arena};
 
     while (!token_is(close_kind)) {
         Ast_Call_Item *item_comp = ast_new(Ast_Call_Item, AST_CALL_ITEM, token_get(), AST_EXPR);
@@ -278,14 +277,13 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0) {
     if (token_expect(OPEN_SCOPE)) { // @todo: Fix error message here, it doesn't show proper token context
         Token *token_block = token_get();
 
-        Arena *scratch = pctx->scratch;
-        Scratch_Scope __scope(scratch);
-        if (!scope_defined_outside) scope = begin_stmt_scope(scratch, token_block);
+        Scratch_Scope scratch(pctx->scratch);
+        if (!scope_defined_outside) scope = begin_stmt_scope(scratch.arena, token_block);
         do {
             Token *token = token_get();
 
             if (token_match_keyword(pctx->keyword_return)) {
-                Array<Ast_Expr *> expr = {scratch};
+                Array<Ast_Expr *> expr = {scratch.arena};
                 if (!token_is_scope()) {
                     do {
                         Ast_Expr *subexpr = parse_expr();
@@ -306,7 +304,7 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0) {
             else if (token_match_keyword(pctx->keyword_switch)) {
                 Ast_Switch *result = ast_new(Ast_Switch, AST_SWITCH, token, AST_STMT);
                 result->value = parse_expr();
-                result->cases = {scratch};
+                result->cases = {scratch.arena};
 
                 token_expect(OPEN_SCOPE);
                 do {
@@ -319,7 +317,7 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0) {
                     if (token_match_pound(pctx->intern("fallthrough"_s)))
                         switch_case->fallthrough = true;
 
-                    switch_case->labels = {scratch};
+                    switch_case->labels = {scratch.arena};
                     do {
                         switch_case->labels.add(parse_expr());
                     } while (token_match(TK_Comma));
@@ -359,7 +357,7 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0) {
             }
 
             else if (token_match_keyword(pctx->keyword_for)) {
-                Ast_Scope *for_scope = begin_stmt_scope(scratch, token_get());
+                Ast_Scope *for_scope = begin_stmt_scope(scratch.arena, token_get());
                 Ast_Expr *init = 0;
                 Ast_Expr *cond = 0;
                 Ast_Expr *iter = 0;
@@ -385,7 +383,7 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0) {
             }
 
             else if (token_match_keyword(pctx->keyword_if)) {
-                Array<Ast_If_Node *> if_nodes = {scratch};
+                Array<Ast_If_Node *> if_nodes = {scratch.arena};
                 Ast_Expr *expr = parse_expr();
                 Ast_Expr *init_val = parse_init_stmt(expr);
                 if (init_val != expr) {
@@ -421,7 +419,7 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0) {
                 scope->stmts.add(result_if);
             }
             else if (token_is(TK_Identifier) && token_is(TK_Comma, 1)) {
-                Array<Ast_Decl *> decls = {scratch};
+                Array<Ast_Decl *> decls = {scratch.arena};
                 do {
                     Token *name = token_match(TK_Identifier);
                     Ast_Decl *decl = ast_var(name, 0, name->intern_val, 0);
@@ -461,10 +459,9 @@ parse_stmt_scope(Ast_Scope *scope_defined_outside = 0) {
 
 CORE_Static Ast_Lambda *
 parse_lambda(Token *token) {
-    Arena *scratch = pctx->scratch;
-    Scratch_Scope __scope(scratch);
+    Scratch_Scope scratch(pctx->scratch);
 
-    Array<Ast_Decl *> params = {scratch};
+    Array<Ast_Decl *> params = {scratch.arena};
     if (!token_is(TK_CloseParen)) {
         for (;;) {
             Token *name = token_get();
@@ -487,7 +484,7 @@ parse_lambda(Token *token) {
     }
     token_expect(TK_CloseParen);
 
-    Array<Ast_Expr *> ret = {scratch};
+    Array<Ast_Expr *> ret = {scratch.arena};
     if (token_match(TK_Colon)) {
         do {
             Ast_Expr *typespec = parse_expr();
@@ -696,11 +693,10 @@ parse_assign_expr() {
 
 CORE_Static Ast_Decl *
 parse_struct(Token *pos) {
-    Arena *scratch = pctx->scratch;
-    Scratch_Scope __scope(scratch);
+    Scratch_Scope scratch(pctx->scratch);
 
     token_match(OPEN_SCOPE);
-    Ast_Scope *scope = begin_decl_scope(scratch, token_get());
+    Ast_Scope *scope = begin_decl_scope(scratch.arena, token_get());
     do {
         Token *token = token_expect(TK_Identifier);
         token_expect(TK_Colon);
@@ -721,13 +717,12 @@ parse_struct(Token *pos) {
 
 CORE_Static Ast_Decl *
 parse_enum(Token *pos) {
-    Arena *scratch = pctx->scratch;
-    Scratch_Scope __scope(scratch);
+    Scratch_Scope scratch(pctx->scratch);
     Ast_Expr *typespec = parse_optional_type();
     Token *flag = token_match_pound(pctx->intern_flag);
 
     token_match(OPEN_SCOPE);
-    Ast_Scope *scope = begin_decl_scope(scratch, token_get());
+    Ast_Scope *scope = begin_decl_scope(scratch.arena, token_get());
     do {
         Token *name = token_expect(TK_Identifier);
         Ast_Expr *value = 0;
@@ -947,8 +942,7 @@ parse_decl(B32 is_global) {
 CORE_Static void
 parse_file(Ast_File *file) {
     assert(file);
-    Arena *scratch = pctx->scratch;
-    Scratch_Scope __scope(scratch);
+    Scratch_Scope scratch(pctx->scratch);
 
     if (!file->filecontent.len) {
         file->filecontent = os_read_file(pctx->perm, file->absolute_file_path);