Embrace optional new/const in the language tour

examples/README.md

@@ -21,17 +21,46 @@ The original sources for the (large) samples were copied from the
 
 ## New sources
 
-Consolidated and reworked versions of the original sources have been developed,
-and are found under these folders:
+Consolidated and reworked versions of the original sources
+are under these folders:
 
 - `examples/*/lib`
 - `examples/*/test`
 
-As can be expected, Travis jobs run the
+Travis jobs run the following:
 
 - Analyzer over both `lib` and `test`
 - Tests under `test`
 
+You can run some or all of these at the command line, as well.
+
+To run only the analyzer:
+
+```
+cd examples
+dartanalyzer --preview-dart-2 .
+```
+
+To run both the analyzer and tests:
+
+```
+./scripts/analyze-and-test-examples.sh`
+```
+
+If you get a warning about test failures or analysis errors,
+you might need to update one or more analyzer results files
+(for example, `examples/misc/analyzer-2-results.txt`).
+
+To update an analyzer results file:
+
+1. Run `./scripts/analyze-and-test-examples.sh  --save-logs`.
+2. Look at the diffs for the results files.
+3. If the diffs look good but some comments are missing,
+   add back the comments that are still relevant.
+4. Run `./scripts/analyze-and-test-examples.sh` to confirm that
+   your changes are good.
+
+
 ### File organisation for the Tours
 
 The new Language Tour sources are under `lib/language_tour` and `test/language_tour`.

examples/misc/analyzer-2-results.txt

@@ -1,5 +1,5 @@
 Analyzing lib, test...
 # https://github.com/dart-lang/sdk/issues/32236 - flow analysis can't yet figure out that the variable is of type Person.
-  error • 'Object' doesn't extend 'SomeBaseClass' at lib/language_tour/generics/misc.dart:28:23 • type_argument_not_matching_bounds
+  error • 'Object' doesn't extend 'SomeBaseClass' at lib/language_tour/generics/misc.dart:28:19 • type_argument_not_matching_bounds
   error • A value of type 'dynamic' can't be assigned to a variable of type 'Person' at lib/library_tour/core/hash_code.dart:25:21 • invalid_assignment
 2 errors found.

examples/misc/lib/language_tour/built_in_types.dart

@@ -106,12 +106,12 @@ void miscDeclAnalyzedButNotTested() {
 
   {
     // #docregion map-constructor
-    var gifts = new Map();
+    var gifts = Map();
     gifts['first'] = 'partridge';
     gifts['second'] = 'turtledoves';
     gifts['fifth'] = 'golden rings';
 
-    var nobleGases = new Map();
+    var nobleGases = Map();
     nobleGases[2] = 'helium';
     nobleGases[10] = 'neon';
     nobleGases[18] = 'argon';
@@ -156,9 +156,9 @@ class RunesExample {
     print(clapping.codeUnits);
     print(clapping.runes.toList());
 
-    Runes input = new Runes(
-        '\u2665  \u{1f605}  \u{1f60e}  \u{1f47b}  \u{1f596}  \u{1f44d}');
-    print(new String.fromCharCodes(input));
+    Runes input =
+        Runes('\u2665  \u{1f605}  \u{1f60e}  \u{1f47b}  \u{1f596}  \u{1f44d}');
+    print(String.fromCharCodes(input));
   }
 // #enddocregion runes
 }

examples/misc/lib/language_tour/callable_classes.dart

@@ -4,7 +4,7 @@ class WannabeFunction {
   String call(String a, String b, String c) => '$a $b $c!';
 }
 
-var wf = new WannabeFunction();
+var wf = WannabeFunction();
 var out = wf('Hi', 'there,', 'gang');
 
 main() => print(out);

examples/misc/lib/language_tour/classes/employee.dart

@@ -27,7 +27,7 @@ class Employee extends Person {
 // #enddocregion method-then-constructor
 
 void main() {
-  var emp = new Employee.fromJson({});
+  var emp = Employee.fromJson({});
   // Prints:
   // in Person
   // in Employee

examples/misc/lib/language_tour/classes/impostor.dart

@@ -21,6 +21,6 @@ class Impostor implements Person {
 String greetBob(Person person) => person.greet('Bob');
 
 void main() {
-  print(greetBob(new Person('Kathy')));
-  print(greetBob(new Impostor()));
+  print(greetBob(Person('Kathy')));
+  print(greetBob(Impostor()));
 }

examples/misc/lib/language_tour/classes/logger.dart

@@ -12,7 +12,7 @@ class Logger {
     if (_cache.containsKey(name)) {
       return _cache[name];
     } else {
-      final logger = new Logger._internal(name);
+      final logger = Logger._internal(name);
       _cache[name] = logger;
       return logger;
     }
@@ -28,13 +28,13 @@ class Logger {
 
 void main() {
   // #docregion logger
-  var logger = new Logger('UI');
+  var logger = Logger('UI');
   logger.log('Button clicked');
   // #enddocregion logger
 
-  var l1 = new Logger('log1');
-  var l2 = new Logger('log1');
-  var l3 = new Logger('log2');
+  var l1 = Logger('log1');
+  var l2 = Logger('log1');
+  var l3 = Logger('log2');
 
   assert(identical(l1, l2));
   assert(l1 != l3);

examples/misc/lib/language_tour/classes/no_such_method.dart

@@ -1,5 +1,5 @@
 void main() {
-  dynamic a = new A();
+  dynamic a = A();
   a.foo();
 }
 

examples/misc/lib/language_tour/classes/orchestra.dart

@@ -52,10 +52,10 @@ class Maestro extends Person
 // #enddocregion Musician-and-Maestro
 
 void main() {
-  var director = new Maestro('Allen');
+  var director = Maestro('Allen');
   director.entertainMe(); // Waving hands
 
-  var musician = new Musician('Kathy');
+  var musician = Musician('Kathy');
   musician.canPlayPiano = true;
   musician.entertainMe(); // Playing piano
 }

examples/misc/lib/language_tour/classes/point_with_distance_field.dart

@@ -12,6 +12,6 @@ class Point {
 }
 
 void main() {
-  var p = new Point(2, 3);
+  var p = Point(2, 3);
   print(p.distanceFromOrigin);
 }

examples/misc/lib/language_tour/classes/point_with_distance_method.dart

@@ -12,8 +12,8 @@ class Point {
 }
 
 void main() {
-  var a = new Point(2, 2);
-  var b = new Point(4, 4);
+  var a = Point(2, 2);
+  var b = Point(4, 4);
   var distance = Point.distanceBetween(a, b);
   assert(2.8 < distance && distance < 2.9);
   print(distance);

examples/misc/lib/language_tour/classes/point_with_main.dart

@@ -9,7 +9,7 @@ class Point {
 // #enddocregion class
 
 void main() {
-  var point = new Point();
+  var point = Point();
   point.x = 4; // Use the setter method for x.
   assert(point.x == 4); // Use the getter method for x.
   assert(point.y == null); // Values default to null.

examples/misc/lib/language_tour/classes/proxy.dart

@@ -3,7 +3,7 @@
 // ignore_for_file: deprecated_member_use
 
 void main() {
-  dynamic a = new A();
+  dynamic a = A();
   a.doSomething();
 }
 

examples/misc/lib/language_tour/classes/proxy_alt.dart

@@ -1,5 +1,5 @@
 void main() {
-  dynamic a = new A();
+  dynamic a = A();
   a.doSomething();
   a.doSomeOtherThing();
 }

examples/misc/lib/language_tour/classes/rectangle.dart

@@ -11,7 +11,7 @@ class Rectangle {
 }
 
 void main() {
-  var rect = new Rectangle(3, 4, 20, 15);
+  var rect = Rectangle(3, 4, 20, 15);
   assert(rect.left == 3);
   rect.right = 12;
   assert(rect.left == -8);

examples/misc/lib/language_tour/classes/vector.dart

@@ -5,18 +5,18 @@ class Vector {
 
   /// Overrides + (a + b).
   Vector operator +(Vector v) {
-    return new Vector(x + v.x, y + v.y);
+    return Vector(x + v.x, y + v.y);
   }
 
   /// Overrides - (a - b).
   Vector operator -(Vector v) {
-    return new Vector(x - v.x, y - v.y);
+    return Vector(x - v.x, y - v.y);
   }
 }
 
 void main() {
-  final v = new Vector(2, 3);
-  final w = new Vector(2, 2);
+  final v = Vector(2, 3);
+  final w = Vector(2, 2);
 
   // v == (2, 3)
   assert(v.x == 2 && v.y == 3);

examples/misc/lib/language_tour/comments.dart

@@ -16,7 +16,7 @@ void miscDeclAnalyzedButNotTested() {
       /*
        * This is a lot of work. Consider raising chickens.
 
-      Llama larry = new Llama();
+      Llama larry = Llama();
       larry.feed();
       larry.exercise();
       larry.clean();

examples/misc/lib/language_tour/exceptions.dart

@@ -11,7 +11,7 @@ void cleanLlamaStalls() {}
 void miscDeclAnalyzedButNotTested(bool c) {
   if (c) {
     // #docregion throw-FormatException
-    throw new FormatException('Expected at least 1 section');
+    throw FormatException('Expected at least 1 section');
     // #enddocregion throw-FormatException
   }
 
@@ -23,8 +23,7 @@ void miscDeclAnalyzedButNotTested(bool c) {
 
   {
     // #docregion throw-is-an-expression
-    void distanceTo(Point other) =>
-        throw new UnimplementedError();
+    void distanceTo(Point other) => throw UnimplementedError();
     // #enddocregion throw-is-an-expression
   }
 

examples/misc/lib/language_tour/function_equality.dart

@@ -17,8 +17,8 @@ void main() {
   assert(A.bar == x);
 
   // Comparing instance methods.
-  var v = new A(); // Instance #1 of A
-  var w = new A(); // Instance #2 of A
+  var v = A(); // Instance #1 of A
+  var w = A(); // Instance #2 of A
   var y = w;
   x = w.baz;
 

examples/misc/lib/language_tour/generics/misc.dart

@@ -4,7 +4,7 @@ import 'base_class.dart';
 void miscDeclAnalyzedButNotTested() {
   {
     // #docregion why-generics
-    var names = new List<String>();
+    var names = List<String>();
     names.addAll(['Seth', 'Kathy', 'Lars']);
     names.add(42); // Error // ignore: argument_type_not_assignable
     // #enddocregion why-generics
@@ -25,7 +25,7 @@ void miscDeclAnalyzedButNotTested() {
     // ignore_for_file: 2, type_argument_not_matching_bounds
     // Specifying any non-SomeBaseClass type results in an error.
     // #docregion Foo-Object-error
-    var foo = new Foo<Object>(); //!analysis-issue
+    var foo = Foo<Object>(); //!analysis-issue
     // #enddocregion Foo-Object-error
   }
 }

examples/misc/lib/language_tour/libraries/import_as.dart

@@ -2,7 +2,7 @@ import 'lib1.dart';
 import 'lib2.dart' as lib2;
 
 // Uses Element from lib1.
-Element element1 = new Element();
+Element element1 = Element();
 
 // Uses Element from lib2.
-lib2.Element element2 = new lib2.Element();
+lib2.Element element2 = lib2.Element();

examples/misc/lib/language_tour/libraries/show_hide.dart

@@ -6,5 +6,5 @@ import 'lib1.dart' show foo;
 import 'lib2.dart' hide foo;
 // #enddocregion
 
-Element e = new Element();
+Element e = Element();
 dynamic bar = foo;

examples/misc/lib/language_tour/operators.dart

@@ -18,10 +18,10 @@ void miscDeclAnalyzedButNotTested() {
 
   {
     // #docregion nested-cascades
-    final addressBook = (new AddressBookBuilder()
+    final addressBook = (AddressBookBuilder()
           ..name = 'jenny'
           ..email = '[email protected]'
-          ..phone = (new PhoneNumberBuilder()
+          ..phone = (PhoneNumberBuilder()
                 ..number = '415-555-0100'
                 ..label = 'home')
               .build())
@@ -31,7 +31,7 @@ void miscDeclAnalyzedButNotTested() {
 
   {
     // #docregion cannot-cascade-on-void
-    var sb = new StringBuffer();
+    var sb = StringBuffer();
     sb.write('foo')
         // #enddocregion cannot-cascade-on-void
         /*

examples/misc/lib/language_tour/typedefs/sorted_collection_1.dart

@@ -10,7 +10,7 @@ class SortedCollection {
 int sort(Object a, Object b) => 0;
 
 void main() {
-  SortedCollection coll = new SortedCollection(sort);
+  SortedCollection coll = SortedCollection(sort);
 
   // All we know is that compare is a function,
   // but what type of function?

examples/misc/lib/language_tour/typedefs/sorted_collection_2.dart

@@ -10,7 +10,7 @@ class SortedCollection {
 int sort(Object a, Object b) => 0;
 
 void main() {
-  SortedCollection coll = new SortedCollection(sort);
+  SortedCollection coll = SortedCollection(sort);
   assert(coll.compare is Function);
   assert(coll.compare is Compare);
 }