1 files changed, 80 insertions, 0 deletions
diff --git a/set/set.ha b/set/set.ha
new file mode 100644
index 0000000..2c56efe
--- /dev/null
+++ b/set/set.ha
@@ -0,0 +1,80 @@
+export type set = struct {
+	items: []size,
+};
+
+export type nosuchitem = !void;
+
+export fn add(s: *set, item: size) bool = {
+	for (let i = 0z; i < len(s.items); i += 1) {
+		if (s.items[i] == item) {
+			return false;
+		};
+	};
+	append(s.items, item);
+	return true;
+};
+
+export fn del(s: *set, item: size) bool = {
+	match (contains(*s, item)) {
+	case let i: size =>
+		delete(s.items[i]);
+		return true;
+	case nosuchitem =>
+		return false;
+	};
+};
+
+export fn contains(s: set, item: size) (size | nosuchitem) = {
+	for (let i = 0z; i < len(s.items); i += 1) {
+		if (s.items[i] == item) {
+			return i;
+		};
+	};
+	return nosuchitem;
+};
+
+// Clears all items
+export fn clear(s: *set) void = {
+	delete(s.items[..]);
+};
+
+@test fn add() void = {
+	let s = set {...};
+	assert(add(&s, 1z));
+	assert(len(s.items) == 1);
+	assert(!add(&s, 1z));
+	assert(len(s.items) == 1);
+};
+
+@test fn del() void = {
+	let s = set {...};
+	assert(add(&s, 1z));
+	assert(len(s.items) == 1);
+	assert(del(&s, 1z));
+	assert(len(s.items) == 0);
+	assert(!del(&s, 1z));
+	assert(len(s.items) == 0);
+};
+
+@test fn contains() void = {
+	let s = set {...};
+	assert(add(&s, 1z));
+	assert(!add(&s, 1z));
+	const c = contains(s, 1z);
+	assert(c is size);
+	assert(c as size == 0);
+	assert(add(&s, 2z));
+	const c = contains(s, 2z);
+	assert(c is size);
+	assert(c as size == 1);
+};
+
+@test fn clear() void = {
+	let s = set {...};
+	assert(add(&s, 1z));
+	assert(len(s.items) == 1);
+	assert(!add(&s, 1z));
+	assert(len(s.items) == 1);
+	clear(&s);
+	assert(len(s.items) == 0);
+};