KT-16602: Improve mutable sorting samples, fix sample references

libraries/stdlib/samples/test/samples/collections/arrays.kt

@@ -137,20 +137,20 @@ class Arrays {
         fun sortArray() {
             val intArray = intArrayOf(4, 3, 2, 1)
 
+            // before sorting
             assertPrints(intArray.joinToString(), "4, 3, 2, 1")
 
             intArray.sort()
 
+            // after sorting
             assertPrints(intArray.joinToString(), "1, 2, 3, 4")
         }
 
         @Sample
         fun sortArrayOfComparable() {
-            data class Person(val firstName: String, val lastName: String) : Comparable<Person> {
-                override fun compareTo(other: Person): Int {
-                    return lastName.compareTo(other.lastName)
-                }
-
+            class Person(val firstName: String, val lastName: String) : Comparable<Person> {
+                override fun compareTo(other: Person): Int = this.lastName.compareTo(other.lastName)
+                override fun toString(): String = "$firstName $lastName"
             }
 
             val people = arrayOf(
@@ -159,11 +159,13 @@ class Arrays {
                 Person("Sweyn", "Forkbeard")
             )
 
-            assertPrints(people.joinToString(), "Person(firstName=Ragnar, lastName=Lodbrok), Person(firstName=Bjorn, lastName=Ironside), Person(firstName=Sweyn, lastName=Forkbeard)")
+            // before sorting
+            assertPrints(people.joinToString(), "Ragnar Lodbrok, Bjorn Ironside, Sweyn Forkbeard")
 
             people.sort()
 
-            assertPrints(people.joinToString(), "Person(firstName=Sweyn, lastName=Forkbeard), Person(firstName=Bjorn, lastName=Ironside), Person(firstName=Ragnar, lastName=Lodbrok)")
+            // after sorting
+            assertPrints(people.joinToString(), "Sweyn Forkbeard, Bjorn Ironside, Ragnar Lodbrok")
 
         }
 
@@ -171,13 +173,37 @@ class Arrays {
         fun sortRangeOfArray() {
             val intArray = intArrayOf(4, 3, 2, 1)
 
+            // before sorting
             assertPrints(intArray.joinToString(), "4, 3, 2, 1")
 
             intArray.sort(0, 3)
 
+            // after sorting
             assertPrints(intArray.joinToString(), "2, 3, 4, 1")
         }
 
+        @Sample
+        fun sortRangeOfArrayOfComparable() {
+            class Person(val firstName: String, val lastName: String) : Comparable<Person> {
+                override fun compareTo(other: Person): Int = this.lastName.compareTo(other.lastName)
+                override fun toString(): String = "$firstName $lastName"
+            }
+
+            val people = arrayOf(
+                Person("Ragnar", "Lodbrok"),
+                Person("Bjorn", "Ironside"),
+                Person("Sweyn", "Forkbeard")
+            )
+
+            // before sorting
+            assertPrints(people.joinToString(), "Ragnar Lodbrok, Bjorn Ironside, Sweyn Forkbeard")
+
+            people.sort(0, 2)
+
+            // after sorting
+            assertPrints(people.joinToString(), "Bjorn Ironside, Ragnar Lodbrok, Sweyn Forkbeard")
+        }
+
     }
 
 }

libraries/stdlib/samples/test/samples/collections/collections.kt

@@ -568,33 +568,32 @@ class Collections {
         fun sortMutableList() {
             val mutableList = mutableListOf(4, 3, 2, 1)
 
+            // before sorting
             assertPrints(mutableList.joinToString(), "4, 3, 2, 1")
 
             mutableList.sort()
 
+            // after sorting
             assertPrints(mutableList.joinToString(), "1, 2, 3, 4")
         }
 
         @Sample
-        fun sortRangeOfComparable() {
-            data class Person(val firstName: String, val lastName: String) : Comparable<Person> {
-                override fun compareTo(other: Person): Int {
-                    return lastName.compareTo(other.lastName)
-                }
-
+        fun sortMutableListWith() {
+            // non-comparable class
+            class Person(val firstName: String, val lastName: String) {
+                override fun toString(): String = "$firstName $lastName"
             }
 
-            val people = arrayOf(
+            val people = mutableListOf(
                 Person("Ragnar", "Lodbrok"),
                 Person("Bjorn", "Ironside"),
                 Person("Sweyn", "Forkbeard")
             )
 
-            assertPrints(people.joinToString(), "Person(firstName=Ragnar, lastName=Lodbrok), Person(firstName=Bjorn, lastName=Ironside), Person(firstName=Sweyn, lastName=Forkbeard)")
+            people.sortWith(compareByDescending { it.firstName })
 
-            people.sort(0, 2)
-
-            assertPrints(people.joinToString(), "Person(firstName=Bjorn, lastName=Ironside), Person(firstName=Ragnar, lastName=Lodbrok), Person(firstName=Sweyn, lastName=Forkbeard)")
+            // after sorting
+            assertPrints(people.joinToString(), "Sweyn Forkbeard, Ragnar Lodbrok, Bjorn Ironside")
         }
 
     }