use math library

BUG=

Review URL: https://chromiumcodereview.appspot.com/10878021

AUTHORS

@@ -5,4 +5,5 @@
 
 Google Inc.
 
-Matthew Butler <butler.matthew@gmail.com>
+Matthew Butler <butler.matthew@gmail.com>
+Chris Buckett <chrisbuckett@gmail.com>

src/site/_includes/language-tour/classes/index.markdown

@@ -366,12 +366,14 @@ The distanceTo() method in the following sample is an
 example of an instance method.
 
 {% highlight dart %}
+#import('dart:math');
+
 class Point {
   num x, y;
   Point(this.x, this.y);
 
   num distanceTo(Point other) {
-    return Math.sqrt(((x-other.x)*(x-other.x)) + ((y-other.y)*(y-other.y)));
+    return sqrt(((x-other.x)*(x-other.x)) + ((y-other.y)*(y-other.y)));
   }
 }
 {% endhighlight %}
@@ -569,12 +571,14 @@ Static methods (class methods) do not operate on an instance, and thus
 do not have access to `this`.
 
 {% highlight dart %}
+#import('dart:math');
+
 class Point {
   num x, y;
   Point(this.x, this.y);
 
   static num distanceBetween(Point a, Point b) {
-    return Math.sqrt(((a.x-b.x)*(a.x-b.x)) + ((a.y-b.y)*(a.y-b.y)));
+    return sqrt(((a.x-b.x)*(a.x-b.x)) + ((a.y-b.y)*(a.y-b.y)));
   }
 }
 

src/site/articles/idiomatic-dart/index.html

@@ -66,23 +66,29 @@ <h3>Named constructors</h3>
 <p>Like most dynamically-typed languages, Dart doesn't support overloading. With methods, this isn't much of a limitation because you can always use a different name, but constructors aren't so lucky. To alleviate that, Dart lets you define <em>named constructors</em>:</p>
 
 {% highlight dart %}
+#import('dart:math');
+
 class Point {
   num x, y;
   Point(this.x, this.y);
   Point.zero() : x = 0, y = 0;
   Point.polar(num theta, num radius) {
-    x = Math.cos(theta) * radius;
-    y = Math.sin(theta) * radius;
+    x = cos(theta) * radius;
+    y = sin(theta) * radius;
   }
 }
 {% endhighlight dart 0 %}
 
 <p>Here our Point class has three constructors, a normal one and two named ones. You can use them like so:</p>
 
 {% highlight dart %}
-var a = new Point(1, 2);
-var b = new Point.zero();
-var c = new Point.polar(Math.PI, 4.0);
+#import('dart:math');
+
+main() {
+  var a = new Point(1, 2);
+  var b = new Point.zero();
+  var c = new Point.polar(PI, 4.0);
+}
 {% endhighlight dart 0 %}
 
 <p>Note that we're still using <code>new</code> here when we invoke the named constructor. It isn't just a static method.</p>
@@ -255,9 +261,11 @@ <h2 id="top-level-definitions">Top-level definitions</h2>
 <p>Dart is a "pure" object-oriented language in that everything you can place in a variable is a real object (no mutant "primitives") and every object is an instance of some class. It's not a <em>dogmatic</em> OOP language though. You aren't required to place everything you define inside some class. Instead, you are free to define functions, variables, and even getters and setters at the top level if you want.</p>
 
 {% highlight dart %}
+#import('dart:math');
+
 num abs(num value) => value < 0 ? -value : value;
 
-final TWO_PI = Math.PI * 2.0;
+final TWO_PI = PI * 2.0;
 
 int get today() {
   final date = new Date.now();
@@ -267,7 +275,7 @@ <h2 id="top-level-definitions">Top-level definitions</h2>
 
 <p>Even in languages that don't require you to place everything inside a class or object, like JavaScript, it's still common to do so as a form of namespacing: top-level definitions with the same name could inadvertently collide. To address that, Dart has a library system that allows you to import definitions from other libraries with a prefix applied to disambiguate it. That means you shouldn't <em>need</em> to defensively squirrel your definitions inside classes.</p>
 
-<p>We're still exploring what this actually means for how we define libraries. Most of our code does place definitions inside classes, like Math. It's hard to tell if this is just an ingrained habit we have from other languages or a practice that's also good for Dart. This is an area we want feedback on.</p>
+<p>We're still exploring what this actually means for how we define libraries. For example, the project used to have a Math class, but we moved all functionality from that class to top-level methods inside the dart:math library.</p>
 
 <p>We do have some examples where we use top-level definitions. The first you'll run into is <code>main()</code> which is expected to be defined at the top level. If you work with the DOM, the familiar <code>document</code> and <code>window</code> "variables" are actually top-level getters in Dart.</p>
 
@@ -304,8 +312,11 @@ <h2 id="strings-and-interpolation">Strings and interpolation</h2>
   placing them inside curly braces:</p>
 
 {% highlight dart %}
-var r = 2;
-print('The area of a circle with radius $r is ${Math.PI * r * r}');
+#import('dart:math');
+main() {
+  var r = 2;
+  print('The area of a circle with radius $r is ${PI * r * r}');
+}
 {% endhighlight dart 0 %}
 
 <h2 id="operators">Operators</h2>

src/site/articles/mocking-with-dart/index.markdown

@@ -393,7 +393,7 @@ themselves can be `expect()`-style `Matcher`s, for example:
 {% highlight dart %}
 m.when(callsTo('sqrt', isNegative)).
   alwaysThrow('No imaginary number support');
-m.when(callsTo('sqrt', isNonNegative)).alwaysCall((x) => Math.sqrt(x));
+m.when(callsTo('sqrt', isNonNegative)).alwaysCall((x) => sqrt(x));
 {% endhighlight %}
 
 You don't need to provide argument matchers in `callsTo()` for all arguments of a method, but you do need 

src/site/articles/puzzlers/chapter-2.markdown

@@ -677,9 +677,12 @@ So the mysterious behavior is explained.
 What happens when we do a naive translation to Dart?
 
 {% highlight dart %}
+#import('dart:math');
+
 main() {
   StringBuffer word = null;
-  switch ((Math.random() * 2).toInt()) {
+  var random = new Random();
+  switch ((random.nextDouble() * 2).toInt()) {
     case 1:  word = new StringBuffer('P');
     case 2:  word = new StringBuffer('G');
     default: word = new StringBuffer('M');

src/site/articles/style-guide/index.markdown

@@ -612,8 +612,10 @@ together.
 
 <div class="good">
 {% highlight dart good %}
+#import('dart:math');
+// ...
 /* Rolls both [Dice] and returns the highest rolled value. */
-num greatestRoll(Dice a, Dice b) => Math.max(a.roll(), b.roll());
+num greatestRoll(Dice a, Dice b) => max(a.roll(), b.roll());
 {% endhighlight %}
 </div>
 

src/site/docs/editor/index.html

@@ -337,7 +337,7 @@ <h3>Using autocomplete</h3>
     <p>
     Type a class, interface, or variable name, and then type a period.
     <br />
-    For example, type <code>document.</code> or <code>Math.</code>
+    For example, type <code>document.</code>
     and pause a moment.
     Once the suggestions appear,
     continue typing to pare down the list.
@@ -348,9 +348,9 @@ <h3>Using autocomplete</h3>
     <p>
     Type <b>Ctl+Space</b>.
     <br />
-    For example, type <code>Mat</code>, then Ctl+Space
+    For example, type <code>Str</code>, then Ctl+Space
     to see a list of classes and interfaces
-    that start with "Mat".
+    that start with "Str".
     </p>
   </li>
 </ul>
@@ -410,9 +410,9 @@ <h4>Finding where an API is declared</h4>
 
     <p>
       The editor displays the file that declares the item.
-      For example, if you Command-click Math,
+      For example, if you Command-click String,
       the file that declares the
-      <a href="http://api.dartlang.org/dart_core/Math.html"><code>Math</code></a> type appears.
+      <code>String</code> type appears.
     </p>
   </li>
 </ol>