1 files changed, 26 insertions, 2 deletions
diff --git a/src/libzisp/value/boole.zig b/src/libzisp/value/boole.zig
index d4fbd28..0af7e22 100644
--- a/src/libzisp/value/boole.zig
+++ b/src/libzisp/value/boole.zig
@@ -1,10 +1,34 @@
 const Value = @import("../value.zig").Value;
 const misc = @import("misc.zig");
 
-// These can be accessed from either namespace.
 pub const f = misc.f;
 pub const t = misc.t;
 
+// Zig API
+
+/// Checks if the value is a boole.
+pub fn check(v: Value) bool {
+    return v.bits == f.bits or v.bits == t.bits;
+}
+
+pub fn assert(v: Value) void {
+    if (!check(v)) {
+        v.dump();
+        @panic("not bool");
+    }
+}
+
 pub fn pack(b: bool) Value {
-    return if (b) f else t;
+    return if (b) t else f;
+}
+
+pub fn unpack(v: Value) bool {
+    assert(v);
+    return v.bits == t.bits;
+}
+
+// Zisp API
+
+pub fn pred(v: Value) Value {
+    return if (check(v)) t else f;
 }