From 44cb8a5f769c722356ef57551aa9198f38e311f1 Mon Sep 17 00:00:00 2001
From: HalidOdat <halidodat@gmail.com>
Date: Sat, 19 Jun 2021 13:27:45 +0200
Subject: [PATCH] Shrink `Jim_Scope` size from 12 to 1 byte

We store the `Jim_Scope` as a bit field. We keep 6 bits for the kind
(enough to store 64 different kinds), 1 bit for the tail and another 1
bit for key.
---
 jim.h  | 6 +++---
 test.c | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/jim.h b/jim.h
index 12f38f0..e0a227a 100644
--- a/jim.h
+++ b/jim.h
@@ -25,9 +25,9 @@ typedef enum {
 } Jim_Scope_Kind;
 
 typedef struct {
-    Jim_Scope_Kind kind;
-    int tail;
-    int key;
+    unsigned char kind : 6;
+    unsigned char tail : 1;
+    unsigned char key : 1;
 } Jim_Scope;
 
 typedef struct {
diff --git a/test.c b/test.c
index f25fe59..16f782d 100644
--- a/test.c
+++ b/test.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <assert.h>
 
 #define JIM_IMPLEMENTATION
 #include "./jim.h"
@@ -202,6 +203,8 @@ void test(void)
 
 int main(int argc, char **argv)
 {
+    assert(sizeof(Jim_Scope) == 1);
+
     if (argc >= 2) {
         if (strcmp(argv[1], "record") == 0) {
             record("test_expected.h");