1 files changed, 11 insertions, 2 deletions
diff --git a/src/observable.ts b/src/observable.ts
index bd66963..f43e6e2 100644
--- a/src/observable.ts
+++ b/src/observable.ts
@@ -14,6 +14,14 @@ export class OVar<T> {
         this._value = initial;
     }
 
+    static interval<T>(update: () => T, interval: number): OVar<T> {
+        const o = new OVar(update())
+        const i = setInterval(() => o.value = update(), interval)
+        o.cancel_source = () => clearInterval(i)
+        o.weak = true;
+        return o
+    }
+
     get value() { return this._value }
     set value(v: T) { this._value = v; this.change() }
     change() { this.observers.forEach(o => o(this._value)) }
@@ -43,8 +51,9 @@ export class OVar<T> {
     }
     liftA2<U, V>(other: OVar<U>, fn: (x: T, y: U) => V): OVar<V> {
         const uv = new OVar(fn(this.value, other.value))
-        uv.cancel_source = this.onchange(x => uv.value = fn(x, other.value))
-        uv.cancel_source = other.onchange(y => uv.value = fn(this.value, y))
+        const c1 = this.onchange(x => uv.value = fn(x, other.value))
+        const c2 = other.onchange(y => uv.value = fn(this.value, y))
+        uv.cancel_source = () => { c1(); c2() }
         uv.weak = true
         return uv;
     }