feat(atom): add IReset/ISwap impls for History

thi-ng · Jan 31, 2018 · e1b57de · e1b57de
1 parent 282d989
commit e1b57de
Showing 1 changed file with 26 additions and 10 deletions.
diff --git a/packages/atom/src/history.ts b/packages/atom/src/history.ts
@@ -1,6 +1,8 @@
-import { IAtom } from "./api";
+import { IAtom, IReset, ISwap, SwapFn } from "./api";
 
-export class History<T> {
+export class History<T> implements
+    IReset<T>,
+    ISwap<T> {
 
     state: IAtom<T>;
     maxLen: number;
@@ -17,13 +19,6 @@ export class History<T> {
         this.future = [];
     }
 
-    record() {
-        if (this.history.length == this.maxLen) {
-            this.history.shift();
-        }
-        this.history.push(this.state.deref());
-    }
-
     undo() {
         if (this.history.length) {
             this.future.push(this.state.deref());
@@ -37,4 +32,25 @@ export class History<T> {
             return this.state.reset(this.future.pop());
         }
     }
-}
+
+    reset(val: T) {
+        const prev = this.state.deref(),
+            curr = this.state.reset(val);
+        curr !== prev && this.record(prev);
+        return curr;
+    }
+
+    swap(fn: SwapFn<T>, ...args: any[]) {
+        const prev = this.state.deref(),
+            curr = this.state.swap.apply(this.state, [fn, ...args]);
+        curr !== prev && this.record(prev);
+        return curr;
+    }
+
+    protected record(state: T) {
+        if (this.history.length == this.maxLen) {
+            this.history.shift();
+        }
+        this.history.push(state);
+    }
+}