Move Dart versions of math.min() and math.max() into VM patch file.

sdk/lib/math/math.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Mathematical constants and functions, plus a random number generator.
  *
  * To use this library in your code:
  *
  *     import 'dart:math';
@@ skipping 57 matching lines @@
 
 /**
   * Returns the lesser of two numbers.
   *
   * Returns NaN if either argument is NaN.
   * The lesser of `-0.0` and `0.0` is `-0.0`.
   * If the arguments are otherwise equal (including int and doubles with the
   * same mathematical value) then it is unspecified which of the two arguments
   * is returned.
   */
-T min<T extends num>(T a, T b) {
-  // These partially redundant type checks improve code quality for dart2js.
-  // Most of the improvement is at call sites from the inferred non-null num
-  // return type.
-  if (a is! num) throw new ArgumentError(a);
-  if (b is! num) throw new ArgumentError(b);
-
-  if (a > b) return b;
-  if (a < b) return a;
-  if (b is double) {
-    // Special case for NaN and -0.0. If one argument is NaN return NaN.
-    // [min] must also distinguish between -0.0 and 0.0.
-    if (a is double) {
-      if (a == 0.0) {
-        // a is either 0.0 or -0.0. b is either 0.0, -0.0 or NaN.
-        // The following returns -0.0 if either a or b is -0.0, and it
-        // returns NaN if b is NaN.
-        return (a + b) * a * b;
-      }
-    }
-    // Check for NaN and b == -0.0.
-    if (a == 0 && b.isNegative || b.isNaN) return b;
-    return a;
-  }
-  return a;
-}
+external T min<T extends num>(T a, T b);

[Lasse Reichstein Nielsen, 2017/05/05 06:23:25]

I think this'll be the first patched generic method, so let's make sure we have
good test coverage of it, including the genericity (which we probably don't).

 
 /**
   * Returns the larger of two numbers.
   *
   * Returns NaN if either argument is NaN.
   * The larger of `-0.0` and `0.0` is `0.0`. If the arguments are
   * otherwise equal (including int and doubles with the same mathematical value)
   * then it is unspecified which of the two arguments is returned.
   */
-T max<T extends num>(T a, T b) {
-  // These partially redundant type checks improve code quality for dart2js.
-  // Most of the improvement is at call sites from the inferred non-null num
-  // return type.
-  if (a is! num) throw new ArgumentError(a);
-  if (b is! num) throw new ArgumentError(b);
-
-  if (a > b) return a;
-  if (a < b) return b;
-  if (b is double) {
-    // Special case for NaN and -0.0. If one argument is NaN return NaN.
-    // [max] must also distinguish between -0.0 and 0.0.
-    if (a is double) {
-      if (a == 0.0) {
-        // a is either 0.0 or -0.0. b is either 0.0, -0.0, or NaN.
-        // The following returns 0.0 if either a or b is 0.0, and it
-        // returns NaN if b is NaN.
-        return a + b;
-      }
-    }
-    // Check for NaN.
-    if (b.isNaN) return b;
-    return a;
-  }
-  // max(-0.0, 0) must return 0.
-  if (b == 0 && a.isNegative) return b;
-  return a;
-}
+external T max<T extends num>(T a, T b);
 
 /**
  * A variant of [atan].
  *
  * Converts both arguments to [double]s.
  *
  * Returns the angle in radians between the positive x-axis
  * and the vector ([b],[a]).
  * The result is in the range -PI..PI.
  *
@@ skipping 110 matching lines @@
  */
 external double exp(num x);
 
 /**
  * Converts [x] to a [double] and returns the natural logarithm of the value.
  *
  * Returns negative infinity if [x] is equal to zero.
  * Returns NaN if [x] is NaN or less than zero.
  */
 external double log(num x);