20060303a

1 files changed, 29 insertions, 0 deletions

diff --git a/appl/lib/rand.b b/appl/lib/rand.b
new file mode 100644
index 00000000..3409cdec
--- /dev/null
+++ b/appl/lib/rand.b
@@ -0,0 +1,29 @@
+implement Rand;
+
+include "rand.m";
+
+rsalt: big;
+
+init(seed: int)
+{
+	rsalt = big seed;
+}
+
+MASK: con (big 1<<63)-(big 1);
+
+rand(modulus: int): int
+{
+	rsalt = rsalt * big 1103515245 + big 12345;
+	if(modulus <= 0)
+		return 0;
+	return int (((rsalt&MASK)>>10) % big modulus);
+}
+
+# 0 < modulus < 2^53
+bigrand(modulus: big): big
+{
+	rsalt = rsalt * big 1103515245 + big 12345;
+	if(modulus <= big 0)
+		return big 0;
+	return ((rsalt&MASK)>>10) % modulus;
+}