Initial data commit

Task/Executable-library/Limbo/executable-library-1.limbo

@@ -0,0 +1,53 @@
+implement Execlib;
+
+include "sys.m"; sys: Sys;
+include "draw.m";
+
+Execlib: module {
+	init: fn(ctxt: ref Draw->Context, args: list of string);
+	hailstone: fn(i: big): list of big;
+};
+
+init(nil: ref Draw->Context, nil: list of string)
+{
+	sys = load Sys Sys->PATH;
+
+	seq := hailstone(big 27);
+	l := len seq;
+
+	sys->print("hailstone(27):  ");
+	for(i := 0; i < 4; i++) {
+		sys->print("%bd, ", hd seq);
+		seq = tl seq;
+	}
+	sys->print("⋯");
+	
+	while(len seq > 4)
+		seq = tl seq;
+
+	while(seq != nil) {
+		sys->print(", %bd", hd seq);
+		seq = tl seq;
+	}
+	sys->print(" (length %d)\n", l);
+
+	max := 1;
+	maxn := big 1;
+	for(n := big 2; n < big 100000; n++) {
+		cur := len hailstone(n);
+		if(cur > max) {
+			max = cur;
+			maxn = n;
+		}
+	}
+	sys->print("hailstone(%bd) has length %d\n", maxn, max);
+}
+
+hailstone(i: big): list of big
+{
+	if(i == big 1)
+		return big 1 :: nil;
+	if(i % big 2 == big 0)
+		return i :: hailstone(i / big 2);
+	return i :: hailstone(big 3 * i + big 1);
+}