code review 7368054: sort: use proper mass unit in example

src/pkg/sort/example_keys_test.go

 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package sort_test
 
 import (
         "fmt"
         "sort"
 )
 
 // A couple of type definitions to make the units clear.
-type solarMass float64
+type earthMass float64
 type au float64
 
 // A Planet defines the properties of a solar system object.
 type Planet struct {
         name     string
-        mass     solarMass
+        mass     earthMass
         distance au
 }
 
 // By is the type of a "less" function that defines the ordering of its Planet arguments.
 type By func(p1, p2 *Planet) bool
 
 // Sort is a method on the function type, By, that sorts the argument slice according to the function.
 func (by By) Sort(planets []Planet) {
         ps := &planetSorter{
                 planets: planets,
@@ skipping 57 matching lines @@
         fmt.Println("By distance:", planets)
 
         By(decreasingDistance).Sort(planets)
         fmt.Println("By decreasing distance:", planets)
 
         // Output: By name: [{Earth 1 1} {Mars 0.107 1.5} {Mercury 0.055 0.4} {Venus 0.815 0.7}]
         // By mass: [{Mercury 0.055 0.4} {Mars 0.107 1.5} {Venus 0.815 0.7} {Earth 1 1}]
         // By distance: [{Mercury 0.055 0.4} {Venus 0.815 0.7} {Earth 1 1} {Mars 0.107 1.5}]
         // By decreasing distance: [{Mars 0.107 1.5} {Earth 1 1} {Venus 0.815 0.7} {Mercury 0.055 0.4}]
 }