feat(typescript): 20 状态模式

DesignPattern/20-状态模式.md

@@ -424,3 +424,70 @@ func main() {
 }
 ```
 
+### Typescript
+
+``` typescript
+interface IState {
+  handle();
+}
+
+class OnState implements IState {
+  handle() {
+    console.log("Light is ON");
+  }
+}
+
+class OffState implements IState {
+  handle() {
+    console.log("Light is OFF");
+  }
+}
+
+class BlinkState implements IState {
+  handle() {
+    console.log("Light is Blinking");
+  }
+}
+
+class StateContext {
+  private currentState: IState;
+
+  constructor(state) {
+    this.currentState = state;
+  }
+
+  setState(state: IState) {
+    this.currentState = state;
+  }
+
+  getHandle() {
+    return this.currentState.handle();
+  }
+}
+
+// @ts-ignore
+entry(5, (...args) => {
+  const classMap = {
+    ON: OnState,
+    OFF: OffState,
+    BLINK: BlinkState,
+  };
+
+  let state = new StateContext(new OffState());
+  args.forEach((item) => {
+    state.setState(new classMap[item]());
+    state.getHandle();
+  });
+})("ON")("OFF")("BLINK")("OFF")("ON");
+
+function entry(count: number, fn: (...args: any) => void) {
+  function dfs(...args) {
+    if (args.length < count) {
+      return (arg) => dfs(...args, arg);
+    }
+
+    return fn(...args);
+  }
+  return dfs;
+}
+```