Migrate dart:math to NNBD.

Change-Id: I8da8707957e9b2827e8d8ee0152c7260f7ddecd2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/120060
Reviewed-by: Erik Ernst <eernst@google.com>
Reviewed-by: Leaf Petersen <leafp@google.com>

Author: lrhn

sdk_nnbd/lib/_internal/js_dev_runtime/patch/math_patch.dart

@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// @dart = 2.5
-
 // Patch file for dart:math library.
 import 'dart:_foreign_helper' show JS;
 import 'dart:_js_helper' show patch, nullCheck, notNull;
@@ -12,53 +10,52 @@ import 'dart:typed_data' show ByteData;
 @patch
 @notNull
 T min<T extends num>(@nullCheck T a, @nullCheck T b) =>
-    JS('-dynamic', r'Math.min(#, #)', a, b);
+    JS<T>('-dynamic', r'Math.min(#, #)', a, b);
 
 @patch
 @notNull
 T max<T extends num>(@nullCheck T a, @nullCheck T b) =>
-    JS('-dynamic', r'Math.max(#, #)', a, b);
+    JS<T>('-dynamic', r'Math.max(#, #)', a, b);
 
 @patch
 @notNull
-double sqrt(@nullCheck num x) => JS<num>('!', r'Math.sqrt(#)', x);
+double sqrt(@nullCheck num x) => JS<double>('!', r'Math.sqrt(#)', x);
 
 @patch
 @notNull
-double sin(@nullCheck num radians) => JS<num>('!', r'Math.sin(#)', radians);
+double sin(@nullCheck num radians) => JS<double>('!', r'Math.sin(#)', radians);
 
 @patch
 @notNull
-double cos(@nullCheck num radians) => JS<num>('!', r'Math.cos(#)', radians);
+double cos(@nullCheck num radians) => JS<double>('!', r'Math.cos(#)', radians);
 
 @patch
 @notNull
-double tan(@nullCheck num radians) => JS<num>('!', r'Math.tan(#)', radians);
+double tan(@nullCheck num radians) => JS<double>('!', r'Math.tan(#)', radians);
 
 @patch
 @notNull
-double acos(@nullCheck num x) => JS<num>('!', r'Math.acos(#)', x);
+double acos(@nullCheck num x) => JS<double>('!', r'Math.acos(#)', x);
 
 @patch
 @notNull
-double asin(@nullCheck num x) => JS<num>('!', r'Math.asin(#)', x);
+double asin(@nullCheck num x) => JS<double>('!', r'Math.asin(#)', x);
 
 @patch
 @notNull
-double atan(@nullCheck num x) => JS<num>('!', r'Math.atan(#)', x);
+double atan(@nullCheck num x) => JS<double>('!', r'Math.atan(#)', x);
 
 @patch
 @notNull
 double atan2(@nullCheck num a, @nullCheck num b) =>
-    JS<num>('!', r'Math.atan2(#, #)', a, b);
+    JS<double>('!', r'Math.atan2(#, #)', a, b);
 
 @patch
-@notNull
-double exp(@nullCheck num x) => JS<num>('!', r'Math.exp(#)', x);
+double exp(num x) => JS<double>('!', r'Math.exp(#)', x);
 
 @patch
 @notNull
-double log(@nullCheck num x) => JS<num>('!', r'Math.log(#)', x);
+double log(@nullCheck num x) => JS<double>('!', r'Math.log(#)', x);
 
 @patch
 @notNull
@@ -69,10 +66,10 @@ const int _POW2_32 = 0x100000000;
 
 @patch
 class Random {
-  static Random _secureRandom;
+  static Random? _secureRandom;
 
   @patch
-  factory Random([int seed]) =>
+  factory Random([int? seed]) =>
       (seed == null) ? const _JSRandom() : _Random(seed);
 
   @patch
@@ -88,21 +85,21 @@ class _JSRandom implements Random {
     if (max <= 0 || max > _POW2_32) {
       throw RangeError("max must be in range 0 < max ≤ 2^32, was $max");
     }
-    return JS("int", "(Math.random() * #) >>> 0", max);
+    return JS<int>("int", "(Math.random() * #) >>> 0", max);
   }
 
   /**
    * Generates a positive random floating point value uniformly distributed on
    * the range from 0.0, inclusive, to 1.0, exclusive.
    */
   @notNull
-  double nextDouble() => JS("double", "Math.random()");
+  double nextDouble() => JS<double>("double", "Math.random()");
 
   /**
    * Generates a random boolean value.
    */
   @notNull
-  bool nextBool() => JS("bool", "Math.random() < 0.5");
+  bool nextBool() => JS<bool>("bool", "Math.random() < 0.5");
 }
 
 class _Random implements Random {

sdk_nnbd/lib/math/jenkins_smi_hash.dart

@@ -1,7 +1,6 @@
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// @dart = 2.5
 
 part of dart.math;
 
@@ -34,8 +33,8 @@ class _JenkinsSmiHash {
     return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
   }
 
-  static int hash2(a, b) => finish(combine(combine(0, a), b));
+  static int hash2(int a, int b) => finish(combine(combine(0, a), b));
 
-  static int hash4(a, b, c, d) =>
+  static int hash4(int a, int b, int c, int d) =>
       finish(combine(combine(combine(combine(0, a), b), c), d));
 }

sdk_nnbd/lib/math/math.dart

@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// @dart = 2.5
-
 /// Mathematical constants and functions, plus a random number generator.
 ///
 /// To use this library in your code:

sdk_nnbd/lib/math/point.dart

@@ -1,7 +1,6 @@
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// @dart = 2.5
 
 part of dart.math;
 
@@ -16,14 +15,12 @@ class Point<T extends num> {
 
   String toString() => 'Point($x, $y)';
 
-  /// A `Point` is only equal to another `Point` with the same coordinates.
+  /// Whether [other] is a point with the same coordinates as this point.
   ///
-  /// This point is equal to `other` if, and only if,
-  /// `other` is a `Point` with
-  /// [x] equal to `other.x` and [y] equal to `other.y`.
-  bool operator ==(dynamic other) =>
-      // Cannot change parameter type to `Object` in case some class
-      // inherits the type and uses their argument dynamically.
+  /// Returns `true` if [other] is a [Point] with [x] and [y]
+  /// coordinates equal to the corresponding coordiantes of this point,
+  /// and `false` otherwise.
+  bool operator ==(Object other) =>
       other is Point && x == other.x && y == other.y;
 
   int get hashCode => _JenkinsSmiHash.hash2(x.hashCode, y.hashCode);
@@ -32,25 +29,25 @@ class Point<T extends num> {
   ///
   /// Returns the resulting "vector" as a Point.
   Point<T> operator +(Point<T> other) {
-    return Point<T>(x + other.x, y + other.y);
+    return Point<T>((x + other.x) as T, (y + other.y) as T);
   }
 
   /// Subtract [other] from `this`, as if both points were vectors.
   ///
   /// Returns the resulting "vector" as a Point.
   Point<T> operator -(Point<T> other) {
-    return Point<T>(x - other.x, y - other.y);
+    return Point<T>((x - other.x) as T, (y - other.y) as T);
   }
 
   /// Scale this point by [factor] as if it were a vector.
   ///
   /// *Important* *Note*: This function accepts a `num` as its argument only so
-  /// that you can scale Point<double> objects by an `int` factor. Because the
-  /// star operator always returns the same type of Point that originally called
-  /// it, passing in a double [factor] on a `Point<int>` _causes_ _a_
-  /// _runtime_ _error_ in checked mode.
+  /// that you can scale `Point<double>` objects by an `int` factor. Because the
+  /// `*` operator always returns the same type of `Point` as it is called on,
+  /// passing in a double [factor] on a `Point<int>` _causes_ _a_
+  /// _runtime_ _error_.
   Point<T> operator *(num /*T|int*/ factor) {
-    return Point<T>((x * factor), (y * factor));
+    return Point<T>((x * factor) as T, (y * factor) as T);
   }
 
   /// Get the straight line (Euclidean) distance between the origin (0, 0) and
@@ -71,6 +68,6 @@ class Point<T extends num> {
   T squaredDistanceTo(Point<T> other) {
     var dx = x - other.x;
     var dy = y - other.y;
-    return dx * dx + dy * dy;
+    return (dx * dx + dy * dy) as T;
   }
 }

sdk_nnbd/lib/math/random.dart

@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// @dart = 2.5
-
 part of dart.math;
 
 /// A generator of random bool, int, or double values.
@@ -18,7 +16,7 @@ abstract class Random {
   /// The optional parameter [seed] is used to initialize the
   /// internal state of the generator. The implementation of the
   /// random stream can change between releases of the library.
-  external factory Random([int seed]);
+  external factory Random([int? seed]);
 
   /// Creates a cryptographically secure random number generator.
   ///

sdk_nnbd/lib/math/rectangle.dart

@@ -1,7 +1,6 @@
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// @dart = 2.5
 
 part of dart.math;
 
@@ -33,18 +32,16 @@ abstract class _RectangleBase<T extends num> {
   T get height;
 
   /// The x-coordinate of the right edge.
-  T get right => left + width;
+  T get right => (left + width) as T;
 
   /// The y-coordinate of the bottom edge.
-  T get bottom => top + height;
+  T get bottom => (top + height) as T;
 
   String toString() {
     return 'Rectangle ($left, $top) $width x $height';
   }
 
-  bool operator ==(dynamic other) =>
-      // Can't change argument type to `Object` since subclasses inherit it
-      // and uses their argument dynamically.
+  bool operator ==(Object other) =>
       other is Rectangle &&
       left == other.left &&
       top == other.top &&
@@ -61,7 +58,7 @@ abstract class _RectangleBase<T extends num> {
   ///
   /// Returns the intersection of this and `other`, or `null` if they don't
   /// intersect.
-  Rectangle<T> intersection(Rectangle<T> other) {
+  Rectangle<T>? intersection(Rectangle<T> other) {
     var x0 = max(left, other.left);
     var x1 = min(left + width, other.left + other.width);
 
@@ -70,7 +67,7 @@ abstract class _RectangleBase<T extends num> {
       var y1 = min(top + height, other.top + other.height);
 
       if (y0 <= y1) {
-        return Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
+        return Rectangle<T>(x0, y0, (x1 - x0) as T, (y1 - y0) as T);
       }
     }
     return null;
@@ -92,7 +89,7 @@ abstract class _RectangleBase<T extends num> {
     var left = min(this.left, other.left);
     var top = min(this.top, other.top);
 
-    return Rectangle<T>(left, top, right - left, bottom - top);
+    return Rectangle<T>(left, top, (right - left) as T, (bottom - top) as T);
   }
 
   /// Tests whether `this` entirely contains [another].
@@ -112,19 +109,20 @@ abstract class _RectangleBase<T extends num> {
   }
 
   Point<T> get topLeft => Point<T>(this.left, this.top);
-  Point<T> get topRight => Point<T>(this.left + this.width, this.top);
+  Point<T> get topRight => Point<T>((this.left + this.width) as T, this.top);
   Point<T> get bottomRight =>
-      Point<T>(this.left + this.width, this.top + this.height);
-  Point<T> get bottomLeft => Point<T>(this.left, this.top + this.height);
+      Point<T>((this.left + this.width) as T, (this.top + this.height) as T);
+  Point<T> get bottomLeft => Point<T>(this.left, (this.top + this.height) as T);
 }
 
 /// A class for representing two-dimensional rectangles whose properties are
 /// immutable.
 class Rectangle<T extends num> extends _RectangleBase<T> {
   final T left;
   final T top;
-  final T width;
-  final T height;
+  // Type `num` because constructor cannot cast to `T`.
+  final num _width;
+  final num _height;
 
   /// Create a rectangle spanned by `(left, top)` and
   /// `(left+width, top+height)`.
@@ -139,8 +137,12 @@ class Rectangle<T extends num> extends _RectangleBase<T> {
   /// If `width` and `height` are zero, the "rectangle" comprises only the
   /// single point `(left, top)`.
   const Rectangle(this.left, this.top, T width, T height)
-      : this.width = (width < 0) ? -width * 0 : width, // Inline _clampToZero.
-        this.height = (height < 0) ? -height * 0 : height;
+      : _width = (width < 0) ? -width * 0 : width, // Inline _clampToZero<num>.
+        _height = (height < 0) ? -height * 0 : height;
+
+  T get width => _width as T;
+
+  T get height => _height as T;
 
   /// Create a rectangle spanned by the points [a] and [b];
   ///
@@ -154,9 +156,9 @@ class Rectangle<T extends num> extends _RectangleBase<T> {
   /// Similar for the y-coordinates and the bottom edge.
   factory Rectangle.fromPoints(Point<T> a, Point<T> b) {
     T left = min(a.x, b.x);
-    T width = max(a.x, b.x) - left;
+    T width = (max(a.x, b.x) - left) as T;
     T top = min(a.y, b.y);
-    T height = max(a.y, b.y) - top;
+    T height = (max(a.y, b.y) - top) as T;
     return Rectangle<T>(left, top, width, height);
   }
 }
@@ -205,9 +207,9 @@ class MutableRectangle<T extends num> extends _RectangleBase<T>
   /// Similar for the y-coordinates and the bottom edge.
   factory MutableRectangle.fromPoints(Point<T> a, Point<T> b) {
     T left = min(a.x, b.x);
-    T width = max(a.x, b.x) - left;
+    T width = (max(a.x, b.x) - left) as T;
     T top = min(a.y, b.y);
-    T height = max(a.y, b.y) - top;
+    T height = (max(a.y, b.y) - top) as T;
     return MutableRectangle<T>(left, top, width, height);
   }
 
@@ -245,5 +247,5 @@ class MutableRectangle<T extends num> extends _RectangleBase<T>
 /// Returns `0` if value is int, `0.0` if value is double.
 T _clampToZero<T extends num>(T value) {
   assert(value < 0);
-  return -value * 0;
+  return (-value * 0) as T;
 }