From 78ba60685c4677a3f04d44cdce77fda0cb419579 Mon Sep 17 00:00:00 2001
From: mfranz <mfranz>
Date: Tue, 29 Jul 2008 17:17:09 +0000
Subject: [PATCH] some convenience functions for the built-in bits library

---
 Nasal/bits.nas | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 Nasal/bits.nas

diff --git a/Nasal/bits.nas b/Nasal/bits.nas
new file mode 100644
index 000000000..4c5e9fe43
--- /dev/null
+++ b/Nasal/bits.nas
@@ -0,0 +1,39 @@
+# test whether bit b (range 0..31) is set in integer number n
+var test = func(n, b) {
+	var s = buf(4);
+	setfld(s, 0, 32, n);
+	fld(s, b, 1);
+}
+
+
+# return integer number n with bit b set
+var set = func(n, b) {
+	var s = buf(4);
+	setfld(s, 0, 32, n);
+	setfld(s, b, 1, 1);
+	fld(s, 0, 32);
+}
+
+
+# return integer number n with bit b cleared
+var clear = func(n, b) {
+	var s = buf(4);
+	setfld(s, 0, 32, n);
+	setfld(s, b, 1, 0);
+	fld(s, 0, 32);
+}
+
+
+# return number as bit string
+var string = func(n) {
+	if (!n)
+		return "0";
+	var s = "";
+	while (n) {
+		s = ((var v = int(n / 2)) * 2 != n) ~ s;
+		n = v;
+	}
+	return s;
+}
+
+