add ADT example

1 files changed, 52 insertions, 0 deletions

diff --git a/ADTs/adts.b b/ADTs/adts.b
new file mode 100644
index 0000000..d5ff7e1
--- /dev/null
+++ b/ADTs/adts.b
@@ -0,0 +1,52 @@
+implement ADTs;
+
+include "sys.m";
+include "draw.m";
+
+sys: Sys;
+print: import sys;
+
+ADTs: module {
+	init: fn(nil: ref Draw->Context, nil: list of string);
+
+	Person: adt {
+		age:	int;
+		name:	string;
+		stringify: fn(p: self ref Person): string;
+	};
+};
+
+Town: adt {
+	pop: array of ref Person;
+	name: string;
+	stringify: fn(t: self ref Town): string;
+};
+
+init(nil: ref Draw->Context, nil: list of string) {
+	sys = load Sys Sys->PATH;
+
+	p := ref Person(27, "Spike");
+	print("%s\n", p.name);
+
+	t: Town;
+	t.pop = array[] of {p, ref Person(13, "Ed")};
+	t.name = "Mars";
+
+	town := ref t;
+	print("%s\n", town.stringify());
+
+	exit;
+}
+
+Person.stringify(p: self ref Person): string {
+	return p.name;
+}
+
+Town.stringify(t: self ref Town): string {
+	s := "Name: " + t.name + "\nSize: " + string len t.pop + "\nMembers:";
+
+	for(i := 0; i < len t.pop; i++)
+		s += "\n→ " + t.pop[i].stringify();
+
+	return s;
+}