init source

node_modules/rxjs/_esm2015/internal/operators/pairwise.js

@@ -0,0 +1,29 @@
+import { Subscriber } from '../Subscriber';
+export function pairwise() {
+    return (source) => source.lift(new PairwiseOperator());
+}
+class PairwiseOperator {
+    call(subscriber, source) {
+        return source.subscribe(new PairwiseSubscriber(subscriber));
+    }
+}
+class PairwiseSubscriber extends Subscriber {
+    constructor(destination) {
+        super(destination);
+        this.hasPrev = false;
+    }
+    _next(value) {
+        let pair;
+        if (this.hasPrev) {
+            pair = [this.prev, value];
+        }
+        else {
+            this.hasPrev = true;
+        }
+        this.prev = value;
+        if (pair) {
+            this.destination.next(pair);
+        }
+    }
+}
+//# sourceMappingURL=pairwise.js.map