From 56a67a263d32de6ccc9afb6bd7daa50e4a1e5aee Mon Sep 17 00:00:00 2001
From: Jesse McDonald <nybble41@gmail.com>
Date: Wed, 11 Nov 2009 00:24:07 -0600
Subject: [PATCH] Add an 'undefined' value and a function to convert booleans
 into values.

---
 gc.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/gc.h b/gc.h
index 111546e..acaa6e8 100644
--- a/gc.h
+++ b/gc.h
@@ -32,6 +32,7 @@ typedef intptr_t fixnum_t;
 #define BROKEN_HEART      SPECIAL_VALUE(0)
 #define FALSE_VALUE       SPECIAL_VALUE(1)
 #define TRUE_VALUE        SPECIAL_VALUE(2)
+#define UNDEFINED         SPECIAL_VALUE(3)
 
 #define TYPE_TAG_BOX      TYPE_TAG(0)
 #define TYPE_TAG_VECTOR   TYPE_TAG(1)
@@ -180,6 +181,11 @@ static inline bool is_boolean(value_t v)
   return (v == FALSE_VALUE) || (v == TRUE_VALUE);
 }
 
+static inline value_t make_boolean(bool b)
+{
+  return b ? TRUE_VALUE : FALSE_VALUE;
+}
+
 static inline value_t object_value(void *obj)
 {
   assert((uintptr_t)obj >= 4096);