Doc/chapter 5/update materials

projects/starters/chapter_05/lib/async/async_sample_1.dart

@@ -0,0 +1,48 @@
+import "dart:async";
+
+Future<String> myLongRunningFunction() => Future.delayed(
+      Duration(seconds: 3),
+      () {
+        print("Inside the future");
+        throw Exception("No internet connection!");
+        return "Hello in the future!";
+      },
+    );
+
+void main() {
+  print("Starting main");
+  var futureResult = myLongRunningFunction();
+  print("Immediate result: $futureResult");
+  futureResult
+      .then(
+        (result) {
+          print("Result of function: $result");
+        },
+      )
+      .timeout(
+        Duration(
+          seconds: 1,
+        ),
+      )
+      .catchError(
+        (error) {
+          print("Caught TimeoutException error: $error");
+        },
+        test: (e) => e is TimeoutException,
+      )
+      .catchError(
+        (error) {
+          print("Caught String error: $error");
+        },
+        test: (e) => e is String,
+      )
+      .whenComplete(() {
+        print("Inside whenComplete");
+      });
+  var i = 0;
+  /*while(true){
+    for (int j = 0; j < 1000; j++)
+      print("${i++}");
+  } !!FREEZES!!*/
+  print("Ending main");
+}

projects/starters/chapter_05/lib/async/async_sample_2.dart

@@ -0,0 +1,42 @@
+Future<String> myLongRunningFunction() => Future.delayed(
+      Duration(seconds: 3),
+      () {
+        print("Inside the future");
+        throw Exception("No internet connection!");
+        return "Hello in the future!";
+      },
+    );
+
+Future<String> myAsyncFunction() async {
+  await Future.delayed(Duration(seconds: 3));
+  print("Inside the future");
+  throw Exception("No internet connection");
+  return "Hello in the future";
+}
+
+void asyncVoidFunction() async {
+  print("Starting async void function!");
+  await Future.delayed(Duration(seconds: 1));
+  print("Ending async void function!");
+}
+
+void myAsyncTestFunction() async {
+  print("Starting async func");
+  asyncVoidFunction();
+  //await asyncVoidFunction(); //!ERROR! Cannot await void function
+  print("Calling long running function!");
+  try {
+    var result = await myLongRunningFunction();
+    print("Immediate result: $result");
+  } catch (e) {
+    print("Caught error: $e");
+  } finally {
+    print("Inside finally");
+  }
+}
+
+void main() {
+  print("Starting main function!");
+  myAsyncTestFunction();
+  print("Ending main function!");
+}

projects/starters/chapter_05/lib/async/generator_sample_1.dart

@@ -0,0 +1,16 @@
+import "dart:math";
+
+Iterable<int> calculatePrimes() sync* {
+  yield 2;
+  for (int i = 3; true; i++) {
+    if (calculatePrimes()
+        .takeWhile((prime) => prime <= sqrt(i))
+        .every((prime) => i % prime != 0)) {
+      yield i;
+    }
+  }
+}
+
+void main() {
+  calculatePrimes().take(20).forEach(print);
+}

projects/starters/chapter_05/lib/async/generator_sample_2.dart

@@ -0,0 +1,14 @@
+Stream<int> myStreamGeneratorFunction() async* {
+  yield 1;
+  await Future.delayed(Duration(milliseconds: 200));
+  yield 2;
+  await Future.delayed(Duration(milliseconds: 200));
+  yield 3;
+  await Future.delayed(Duration(milliseconds: 200));
+}
+
+void main() async {
+  await for (var value in myStreamGeneratorFunction()) {
+    print(value);
+  }
+}

projects/starters/chapter_05/pubspec.lock

@@ -7,7 +7,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.8.1"
+    version: "2.9.0"
   boolean_selector:
     dependency: transitive
     description:
@@ -21,35 +21,28 @@ packages:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
-  charcode:
-    dependency: transitive
-    description:
-      name: charcode
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.1"
+    version: "1.2.1"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.1.1"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0"
+    version: "1.16.0"
   fake_async:
     dependency: transitive
     description:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.3.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -66,21 +59,28 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10"
+    version: "0.12.12"
+  material_color_utilities:
+    dependency: transitive
+    description:
+      name: material_color_utilities
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.1.5"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0"
+    version: "1.8.2"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -92,7 +92,7 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.1"
+    version: "1.9.0"
   stack_trace:
     dependency: transitive
     description:
@@ -113,34 +113,27 @@ packages:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.1.1"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.2.1"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.4.2"
-  typed_data:
-    dependency: transitive
-    description:
-      name: typed_data
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.0"
+    version: "0.4.12"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0"
+    version: "2.1.2"
 sdks:
-  dart: ">=2.12.0 <3.0.0"
+  dart: ">=2.17.0-0 <3.0.0"