M14 code cleanup

src/i_introduction/_7_Data_Classes/DataClasses.kt

@@ -19,12 +19,12 @@ fun useFromJava() {
 class Person2(_name: String, _age: Int) { //_name, _age are constructor parameters
     val name: String = _name //property initialization is part of the constructor
       get(): String {
-          return $name // You can access the backing field of property with '$' + property name
+          return field // You can access the backing field of property using 'field'
       }
 
     val age: Int = _age
       get(): Int {
-          return $age
+           return field
       }
 }
 

src/i_introduction/_8_Extension_Functions/JavaCode8.java

@@ -1,10 +1,10 @@
 package i_introduction._8_Extension_Functions;
 
-import i_introduction._8_Extension_Functions.StringExtensions.StringExtensionsPackage;
+import i_introduction._8_Extension_Functions.StringExtensions.ExtensionFunctionsKt;
 import util.JavaCode;
 
 public class JavaCode8 extends JavaCode {
     public void useExtension() {
-        char c = StringExtensionsPackage.lastChar("abc");
+        char c = ExtensionFunctionsKt.lastChar("abc");
     }
 }

src/ii_conventions/_11_Comparison_.kt

@@ -10,7 +10,7 @@ fun compareStrings(s1: String?, s2: String?) {
 }
 
 interface B {
-    fun compareTo(other: B): Int
+    operator fun compareTo(other: B): Int
 }
 
 fun test(b1: B, b2: B) {

src/ii_conventions/_14_InRange.kt

@@ -3,7 +3,7 @@ package ii_conventions
 import util.TODO
 
 interface Container<E> {
-    fun contains(element: E): Boolean
+    operator fun contains(element: E): Boolean
 }
 
 fun inConvention(container: Container<String>) {

src/ii_conventions/_15_OperatorsOverloading.kt

@@ -14,9 +14,9 @@ fun infixNotation() {
 // Predefined operators can be overloaded by the corresponding names.
 // A complete list of operators can be found in the syntax/OperatorOverloading.kt file.
 interface A {
-    fun plus(a: A): A
-    fun times(a: A): A
-    fun not(): A
+    operator fun plus(a: A): A
+    operator fun times(a: A): A
+    operator fun not(): A
 }
 
 fun use(a1: A, a2: A) {

src/ii_conventions/_16_MultiAssignment.kt

@@ -7,8 +7,8 @@ fun multiAssignPair(pair: Pair<Int, String>) {
 }
 
 class MyPair {
-    fun component1(): Int = 1
-    fun component2(): String = "a"
+    operator fun component1(): Int = 1
+    operator fun component2(): String = "a"
 }
 
 fun howItWorks() {

src/ii_conventions/_17_Invoke_.kt

@@ -3,10 +3,10 @@ package ii_conventions
 import util.TODO
 
 interface My {
-    fun invoke(i: Int)
+    operator fun invoke(i: Int)
 }
 
-// Objects with 'invoke' function can by invokable as a function
+// Objects with 'invoke' function marked as 'operator' can by invokable as a function
 fun testTypeWithInvokeMember(my: My) {
     my(1)
 
@@ -24,7 +24,7 @@ fun testFunctionType(f: (Int) -> Int) {
 
 // You can add an 'invoke' extension for any class,
 // but it's better not to overdo it
-fun Int.invoke() { println(this) }
+operator fun Int.invoke() { println(this) }
 
 fun testTypeWithInvokeExtension() {
     1() //huh?..

src/iii_properties/_18_Properties_.kt

@@ -28,14 +28,14 @@ fun usage(sp: SimpleProperty) {
 
 class PropertiesWithCustomAccessors {
     var generatedByDefault: Int = 0
-        set(value: Int) { $generatedByDefault = value }
-        get() = $generatedByDefault
+        set(value: Int) { field = value }
+        get() = field
 
     val propertyWithoutBackingField: Int
         get() = 42
 
     val infiniteRecursion: Int? = Random().nextInt()
-        get() = if ($infiniteRecursion!! < 42) null else infiniteRecursion
+        get() = if (field!! < 42) null else infiniteRecursion
 }
 
 class PropertyExample() {

src/syntax/operatorOverloading.kt

@@ -3,11 +3,11 @@ package syntax.operatorOverloading
 fun compareStrings(s1: String?, s2: String?) {
     s1 == s2
     // is compiled to
-    s1?.equals(s2) ?: s2.identityEquals(null)
+    s1?.equals(s2) ?: s2 === null
 }
 
 interface C {
-    fun compareTo(other: C): Int
+    operator fun compareTo(other: C): Int
 }
 
 fun test(c1: C, c2: C) {
@@ -23,19 +23,19 @@ fun test(c1: C, c2: C) {
 interface A
 interface B {
     //unary operations
-    fun plus()
-    fun minus()
+    operator fun plus()
+    operator fun minus()
 
-    fun inc(): B
-    fun dec(): B
+    operator fun inc(): B
+    operator fun dec(): B
 
     //binary operations
-    fun plus(a: A): B
-    fun minus(a: A): B
-    fun times(a: A): B
-    fun div(a: A): B
-    fun mod(a: A): B
-    fun rangeTo(a: A): B
+    operator fun plus(a: A): B
+    operator fun minus(a: A): B
+    operator fun times(a: A): B
+    operator fun div(a: A): B
+    operator fun mod(a: A): B
+    operator fun rangeTo(a: A): B
 }
 
 @Suppress("UNUSED_CHANGED_VALUE", "UNUSED_VALUE")
@@ -60,11 +60,11 @@ fun binaryAndUnaryOperations(a: A, b: B) {
 }
 
 interface D {
-    fun plusAssign(a: A)
-    fun minusAssign(a: A)
-    fun timesAssign(a: A)
-    fun divAssign(a: A)
-    fun modAssign(a: A)
+    operator fun plusAssign(a: A)
+    operator fun minusAssign(a: A)
+    operator fun timesAssign(a: A)
+    operator fun divAssign(a: A)
+    operator fun modAssign(a: A)
 }
 
 fun assignmentOperations(d: D, a: A) {
@@ -74,7 +74,7 @@ fun assignmentOperations(d: D, a: A) {
 }
 
 interface MyCollection<E> {
-    fun contains(e: E): Boolean
+    operator fun contains(e: E): Boolean
 }
 
 fun conventionForIn(c: MyCollection<A>, a: A) {
@@ -88,8 +88,8 @@ fun conventionForIn(c: MyCollection<A>, a: A) {
 }
 
 interface MyMap<K, V> {
-    fun get(k: K): V
-    fun set(k: K, v: V)
+    operator fun get(k: K): V
+    operator fun set(k: K, v: V)
 }
 
 fun conventionForGet(map: MyMap<A, B>, a: A, b: B) {

src/syntax/properties.kt

@@ -8,11 +8,11 @@ class A {
     var propertyWithCustomAccessors: Int = 1
         set(v: Int) {
             println("setter")
-            $propertyWithCustomAccessors = v
+            field = v
         }
         get() {
             println("getter")
-            return $propertyWithCustomAccessors
+            return field
         }
 
     val propertyWithoutBackingField: Int

test/ii_conventions/_11_Comparison.kt

@@ -21,5 +21,5 @@ class _11_Comparison {
         Assert.assertTrue("The date ${first.s} should be after ${second.s}", first > second)
     }
 
-    fun MyDate.compareTo(other: MyDate): Int = todoTask11()
+    operator fun MyDate.compareTo(other: MyDate): Int = todoTask11()
 }

test/ii_conventions/_17_Invoke.kt

@@ -20,6 +20,6 @@ class _17_Invoke {
         testInvokable(0) { it }
     }
 
-    fun Invokable.invoke() = todoTask17()
+    operator fun Invokable.invoke() = todoTask17()
     fun Invokable.getNumberOfInvocations() = todoTask17()
 }