Update assertion syntax in code examples pr967

doc/handbook/Advanced Types.md

@@ -14,15 +14,15 @@ function extend<First, Second>(first: First, second: Second): First & Second {
     const result: Partial<First & Second> = {};
     for (const prop in first) {
         if (first.hasOwnProperty(prop)) {
-            (<First>result)[prop] = first[prop];
+            (result as First)[prop] = first[prop];
         }
     }
     for (const prop in second) {
         if (second.hasOwnProperty(prop)) {
-            (<Second>result)[prop] = second[prop];
+            (result as Second)[prop] = second[prop];
         }
     }
-    return <First & Second>result;
+    return result as First & Second;
 }
 
 class Person {
@@ -151,11 +151,10 @@ else if (pet.fly) {
 ```ts
 let pet = getSmallPet();
 
-if ((<Fish>pet).swim) {
-    (<Fish>pet).swim();
-}
-else {
-    (<Bird>pet).fly();
+if ((pet as Fish).swim) {
+    (pet as Fish).swim();
+} else if ((pet as Bird).fly) {
+    (pet as Bird).fly();
 }
 ```
 
@@ -170,7 +169,7 @@ TypeScript里的*类型守卫*机制让它成为了现实。
 
 ```ts
 function isFish(pet: Fish | Bird): pet is Fish {
-    return (<Fish>pet).swim !== undefined;
+    return (pet as Fish).swim !== undefined;
 }
 ```
 

doc/handbook/Interfaces.md

@@ -453,7 +453,7 @@ interface Square extends Shape {
     sideLength: number;
 }
 
-let square = <Square>{};
+let square = {} as Square;
 square.color = "blue";
 square.sideLength = 10;
 ```
@@ -473,7 +473,7 @@ interface Square extends Shape, PenStroke {
     sideLength: number;
 }
 
-let square = <Square>{};
+let square = {} as Square;
 square.color = "blue";
 square.sideLength = 10;
 square.penWidth = 5.0;
@@ -494,7 +494,7 @@ interface Counter {
 }
 
 function getCounter(): Counter {
-    let counter = <Counter>function (start: number): string { return '' };
+    let counter = (function (start: number) { }) as Counter;
     counter.interval = 123;
     counter.reset = function () { };
     return counter;

doc/handbook/Type Compatibility.md

@@ -128,8 +128,8 @@ function listenEvent(eventType: EventType, handler: (n: Event) => void) {
 listenEvent(EventType.Mouse, (e: MouseEvent) => console.log(e.x + ',' + e.y));
 
 // Undesirable alternatives in presence of soundness
-listenEvent(EventType.Mouse, (e: Event) => console.log((<MouseEvent>e).x + ',' + (<MouseEvent>e).y));
-listenEvent(EventType.Mouse, <(e: Event) => void>((e: MouseEvent) => console.log(e.x + ',' + e.y)));
+listenEvent(EventType.Mouse, (e: Event) => console.log((e as MouseEvent).x + "," + (e as MouseEvent).y));
+listenEvent(EventType.Mouse, ((e: MouseEvent) => console.log(e.x + "," + e.y)) as (e: Event) => void);
 
 // Still disallowed (clear error). Type safety enforced for wholly incompatible types
 listenEvent(EventType.Mouse, (e: number) => console.log(e));