Rename CharSequence.get to charAt

This is done for JVM interoperability. There's still a member function
String.get() and an extension function "get" on CharSequence

 #KT-1730 Fixed
 #KT-5389 Fixed

compiler/backend/src/org/jetbrains/jet/codegen/intrinsics/IntrinsicMethods.java

@@ -113,7 +113,6 @@ public class IntrinsicMethods {
         declareIntrinsicFunction("Boolean", "not", 0, new Not());
 
         declareIntrinsicFunction("String", "plus", 1, new Concat());
-        declareIntrinsicFunction("CharSequence", "get", 1, new StringGetChar());
         declareIntrinsicFunction("String", "get", 1, new StringGetChar());
 
         declareIntrinsicFunction("Cloneable", "clone", 0, CLONE);

compiler/backend/src/org/jetbrains/jet/codegen/intrinsics/StringGetChar.kt

@@ -23,20 +23,21 @@ import org.jetbrains.jet.codegen.StackValue
 import org.jetbrains.jet.lang.psi.JetExpression
 
 public class StringGetChar : LazyIntrinsicMethod() {
-    override fun generateImpl(codegen: ExpressionCodegen,
-                              returnType: Type,
-                              element: PsiElement?,
-                              arguments: List<JetExpression>,
-                              receiver: StackValue): StackValue {
-
+    override fun generateImpl(
+            codegen: ExpressionCodegen,
+            returnType: Type,
+            element: PsiElement?,
+            arguments: List<JetExpression>,
+            receiver: StackValue
+    ): StackValue {
         return StackValue.operation(Type.CHAR_TYPE) {
             if (receiver != StackValue.none()) {
                 receiver.put(receiver.type, it)
             }
             if (!arguments.isEmpty()) {
-                codegen.gen(arguments.get(0)).put(Type.INT_TYPE, it)
+                codegen.gen(arguments.first()).put(Type.INT_TYPE, it)
             }
-            it.invokeinterface("java/lang/CharSequence", "charAt", "(I)C")
+            it.invokevirtual("java/lang/String", "charAt", "(I)C", false)
         }
     }
 }

compiler/frontend/src/org/jetbrains/jet/lang/evaluate/OperationsMapGenerated.kt

@@ -419,6 +419,7 @@ private val binaryOperations: HashMap<BinaryOperationKey<*, *>, Pair<Function2<A
     binaryOperation(SHORT, LONG, "times", { a, b -> a.times(b) }, { a, b -> a.multiply(b) }),
     binaryOperation(SHORT, SHORT, "times", { a, b -> a.times(b) }, { a, b -> a.multiply(b) }),
     binaryOperation(SHORT, ANY, "equals", { a, b -> a.equals(b) }, emptyBinaryFun),
+    binaryOperation(STRING, INT, "charAt", { a, b -> a.charAt(b) }, emptyBinaryFun),
     binaryOperation(STRING, STRING, "compareTo", { a, b -> a.compareTo(b) }, emptyBinaryFun),
     binaryOperation(STRING, INT, "get", { a, b -> a.get(b) }, emptyBinaryFun),
     binaryOperation(STRING, ANY, "plus", { a, b -> a.plus(b) }, emptyBinaryFun),

compiler/testData/builtin-classes.txt

@@ -294,7 +294,7 @@ public final class CharRange : kotlin.Range<kotlin.Char>, kotlin.Progression<kot
 }
 
 public trait CharSequence {
-    public abstract fun get(/*0*/ index: kotlin.Int): kotlin.Char
+    public abstract fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
     public abstract fun length(): kotlin.Int
 }
 
@@ -1428,8 +1428,9 @@ public final class ShortRange : kotlin.Range<kotlin.Short>, kotlin.Progression<k
 
 public final class String : kotlin.Comparable<kotlin.String>, kotlin.CharSequence {
     /*primary*/ public constructor String()
+    public open override /*1*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
     public open override /*1*/ fun compareTo(/*0*/ other: kotlin.String): kotlin.Int
-    public open override /*1*/ fun get(/*0*/ index: kotlin.Int): kotlin.Char
+    public final fun get(/*0*/ index: kotlin.Int): kotlin.Char
     public open override /*1*/ fun length(): kotlin.Int
     public final fun plus(/*0*/ other: kotlin.Any?): kotlin.String
 }

compiler/testData/codegen/boxWithStdlib/strings/kt5389_stringBuilderGet.kt

@@ -0,0 +1,4 @@
+fun box(): String {
+    val sb = StringBuilder("OK")
+    return "${sb.get(0)}${sb[1]}"
+}

compiler/testData/diagnostics/tests/MergePackagesWithJava.txt

@@ -4473,7 +4473,7 @@ package java {
             public open fun append(/*0*/ p0: kotlin.String!): java.lang.AbstractStringBuilder!
             public open fun appendCodePoint(/*0*/ p0: kotlin.Int): java.lang.AbstractStringBuilder!
             public open fun capacity(): kotlin.Int
-            public open fun charAt(/*0*/ p0: kotlin.Int): kotlin.Char
+            public open override /*1*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
             public open fun codePointAt(/*0*/ p0: kotlin.Int): kotlin.Int
             public open fun codePointBefore(/*0*/ p0: kotlin.Int): kotlin.Int
             public open fun codePointCount(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.Int
@@ -7971,7 +7971,7 @@ package java {
             private final var hash: kotlin.Int
             private final var hash32: kotlin.Int
             private final val value: kotlin.CharArray!
-            public open fun charAt(/*0*/ p0: kotlin.Int): kotlin.Char
+            public open override /*1*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
             public open fun codePointAt(/*0*/ p0: kotlin.Int): kotlin.Int
             public open fun codePointBefore(/*0*/ p0: kotlin.Int): kotlin.Int
             public open fun codePointCount(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.Int
@@ -8084,7 +8084,7 @@ package java {
             public open override /*1*/ fun append(/*0*/ p0: kotlin.String!): java.lang.StringBuffer!
             public open override /*1*/ fun appendCodePoint(/*0*/ p0: kotlin.Int): java.lang.StringBuffer!
             public open override /*1*/ fun capacity(): kotlin.Int
-            public open override /*1*/ fun charAt(/*0*/ p0: kotlin.Int): kotlin.Char
+            public open override /*2*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
             public open override /*1*/ fun codePointAt(/*0*/ p0: kotlin.Int): kotlin.Int
             public open override /*1*/ fun codePointBefore(/*0*/ p0: kotlin.Int): kotlin.Int
             public open override /*1*/ fun codePointCount(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.Int
@@ -8155,7 +8155,7 @@ package java {
             public open override /*1*/ fun append(/*0*/ p0: kotlin.String!): java.lang.StringBuilder!
             public open override /*1*/ fun appendCodePoint(/*0*/ p0: kotlin.Int): java.lang.StringBuilder!
             public open override /*1*/ /*fake_override*/ fun capacity(): kotlin.Int
-            public open override /*1*/ /*fake_override*/ fun charAt(/*0*/ p0: kotlin.Int): kotlin.Char
+            public open override /*2*/ /*fake_override*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
             public open override /*1*/ /*fake_override*/ fun codePointAt(/*0*/ p0: kotlin.Int): kotlin.Int
             public open override /*1*/ /*fake_override*/ fun codePointBefore(/*0*/ p0: kotlin.Int): kotlin.Int
             public open override /*1*/ /*fake_override*/ fun codePointCount(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.Int

compiler/testData/diagnostics/tests/cast/neverSucceeds/MappedSubtypes.txt

@@ -14,8 +14,8 @@ internal final class JSub : java.lang.CharSequence {
 
 internal final class Sub : kotlin.CharSequence {
     public constructor Sub()
+    public abstract override /*1*/ /*fake_override*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    public abstract override /*1*/ /*fake_override*/ fun get(/*0*/ index: kotlin.Int): kotlin.Char
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public abstract override /*1*/ /*fake_override*/ fun length(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String

compiler/testData/diagnostics/tests/j+k/kt1730_implementCharSequence.kt

@@ -0,0 +1,24 @@
+// KT-1730 Method which has been implemented by Java is recognized to be abstract.
+
+// FILE: C.java
+public class C implements java.lang.CharSequence {
+    @Override
+    public int length() {
+        return 3;
+    }
+    @Override
+    public char charAt(int index) {
+        return 48;
+    }
+    @Override
+    public CharSequence subSequence(int start, int end) {
+        return "ab";
+    }
+    @Override
+    public String toString() {
+        return "abc";
+    }
+}
+
+// FILE: T.kt
+class T : C()

compiler/testData/diagnostics/tests/j+k/kt1730_implementCharSequence.txt

@@ -0,0 +1,21 @@
+package
+
+public open class C : kotlin.CharSequence {
+    public constructor C()
+    java.lang.Override() public open override /*1*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    java.lang.Override() public open override /*1*/ fun length(): kotlin.Int
+    java.lang.Override() public open fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
+    java.lang.Override() public open override /*1*/ fun toString(): kotlin.String!
+}
+
+internal final class T : C {
+    public constructor T()
+    java.lang.Override() public open override /*1*/ /*fake_override*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    java.lang.Override() public open override /*1*/ /*fake_override*/ fun length(): kotlin.Int
+    java.lang.Override() public open override /*1*/ /*fake_override*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
+    java.lang.Override() public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String!
+}

compiler/testData/diagnostics/tests/scopes/kt955.txt

@@ -4478,7 +4478,7 @@ package java {
             public open fun append(/*0*/ p0: kotlin.String!): java.lang.AbstractStringBuilder!
             public open fun appendCodePoint(/*0*/ p0: kotlin.Int): java.lang.AbstractStringBuilder!
             public open fun capacity(): kotlin.Int
-            public open fun charAt(/*0*/ p0: kotlin.Int): kotlin.Char
+            public open override /*1*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
             public open fun codePointAt(/*0*/ p0: kotlin.Int): kotlin.Int
             public open fun codePointBefore(/*0*/ p0: kotlin.Int): kotlin.Int
             public open fun codePointCount(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.Int
@@ -7976,7 +7976,7 @@ package java {
             private final var hash: kotlin.Int
             private final var hash32: kotlin.Int
             private final val value: kotlin.CharArray!
-            public open fun charAt(/*0*/ p0: kotlin.Int): kotlin.Char
+            public open override /*1*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
             public open fun codePointAt(/*0*/ p0: kotlin.Int): kotlin.Int
             public open fun codePointBefore(/*0*/ p0: kotlin.Int): kotlin.Int
             public open fun codePointCount(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.Int
@@ -8089,7 +8089,7 @@ package java {
             public open override /*1*/ fun append(/*0*/ p0: kotlin.String!): java.lang.StringBuffer!
             public open override /*1*/ fun appendCodePoint(/*0*/ p0: kotlin.Int): java.lang.StringBuffer!
             public open override /*1*/ fun capacity(): kotlin.Int
-            public open override /*1*/ fun charAt(/*0*/ p0: kotlin.Int): kotlin.Char
+            public open override /*2*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
             public open override /*1*/ fun codePointAt(/*0*/ p0: kotlin.Int): kotlin.Int
             public open override /*1*/ fun codePointBefore(/*0*/ p0: kotlin.Int): kotlin.Int
             public open override /*1*/ fun codePointCount(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.Int
@@ -8160,7 +8160,7 @@ package java {
             public open override /*1*/ fun append(/*0*/ p0: kotlin.String!): java.lang.StringBuilder!
             public open override /*1*/ fun appendCodePoint(/*0*/ p0: kotlin.Int): java.lang.StringBuilder!
             public open override /*1*/ /*fake_override*/ fun capacity(): kotlin.Int
-            public open override /*1*/ /*fake_override*/ fun charAt(/*0*/ p0: kotlin.Int): kotlin.Char
+            public open override /*2*/ /*fake_override*/ fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
             public open override /*1*/ /*fake_override*/ fun codePointAt(/*0*/ p0: kotlin.Int): kotlin.Int
             public open override /*1*/ /*fake_override*/ fun codePointBefore(/*0*/ p0: kotlin.Int): kotlin.Int
             public open override /*1*/ /*fake_override*/ fun codePointCount(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.Int

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -6294,6 +6294,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("kt1730_implementCharSequence.kt")
+            public void testKt1730_implementCharSequence() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/j+k/kt1730_implementCharSequence.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("kt2152.kt")
             public void testKt2152() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/j+k/kt2152.kt");

compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java

@@ -2832,6 +2832,12 @@ public class BlackBoxWithStdlibCodegenTestGenerated extends AbstractBlackBoxCode
             doTestWithStdlib(fileName);
         }
 
+        @TestMetadata("kt5389_stringBuilderGet.kt")
+        public void testKt5389_stringBuilderGet() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/strings/kt5389_stringBuilderGet.kt");
+            doTestWithStdlib(fileName);
+        }
+
         @TestMetadata("stringPlusOnlyWorksOnString.kt")
         public void testStringPlusOnlyWorksOnString() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/strings/stringPlusOnlyWorksOnString.kt");

core/builtins/native/kotlin/CharSequence.kt

@@ -17,7 +17,7 @@
 package kotlin
 
 public trait CharSequence {
-    public fun get(index: Int): Char
-
     public fun length(): Int
+
+    public fun charAt(index: Int): Char
 }

core/builtins/native/kotlin/String.kt

@@ -19,9 +19,11 @@ package kotlin
 public class String : Comparable<String>, CharSequence {
     public fun plus(other: Any?): String
 
-    public override fun compareTo(other: String): Int
-
-    public override fun get(index: Int): Char
+    public fun get(index: Int): Char
 
     public override fun length(): Int
+
+    public override fun charAt(index: Int): Char
+
+    public override fun compareTo(other: String): Int
 }

js/js.libraries/src/core/string.kt

@@ -27,8 +27,6 @@ public fun String.split(regex: String, limit: Int): Array<String> = noImpl
 native public fun String.substring(beginIndex : Int) : String = noImpl
 native public fun String.substring(beginIndex : Int, endIndex : Int) : String = noImpl
 
-native public fun String.charAt(index : Int) : Char = noImpl
-
 native public fun String.concat(str : String) : String = noImpl
 
 native public fun String.match(regex : String) : Array<String> = noImpl

js/js.translator/src/org/jetbrains/k2js/translate/intrinsic/functions/factories/StringOperationFIF.java

@@ -26,7 +26,9 @@ public final class StringOperationFIF extends CompositeFIF {
     public static final FunctionIntrinsicFactory INSTANCE = new StringOperationFIF();
 
     private StringOperationFIF() {
-        add(pattern("kotlin", "CharSequence", "get").checkOverridden(), new BuiltInFunctionIntrinsic("charAt"));
+        add(pattern("kotlin", "String", "get"), new BuiltInFunctionIntrinsic("charAt"));
+        // This intrinsic is needed because charAt is a public function taking one parameter and thus its name would be mangled otherwise
+        add(pattern("kotlin", "CharSequence", "charAt").checkOverridden(), new BuiltInFunctionIntrinsic("charAt"));
         add(pattern("kotlin", "CharSequence", "length").checkOverridden(), LENGTH_PROPERTY_INTRINSIC);
         add(pattern("kotlin.js", "isEmpty").isExtensionOf("kotlin.CharSequence"), IS_EMPTY_INTRINSIC);
     }

libraries/stdlib/src/kotlin/text/Strings.kt

@@ -67,6 +67,8 @@ public val String.indices: IntRange
 public val CharSequence.length: Int
     get() = length()
 
+public fun CharSequence.get(index: Int): Char = this.charAt(index)
+
 /**
  * Returns a subsequence specified by given set of indices.
  */

libraries/stdlib/src/kotlin/text/StringsJVM.kt

@@ -75,8 +75,6 @@ public fun String(stringBuilder: java.lang.StringBuilder): String = java.lang.St
 
 public fun String.replaceFirst(regex: String, replacement: String): String = (this as java.lang.String).replaceFirst(regex, replacement)
 
-public fun String.charAt(index: Int): Char = (this as java.lang.String).charAt(index)
-
 public fun String.split(regex: String, limit: Int): Array<String> = (this as java.lang.String).split(regex, limit)
 
 public fun String.codePointAt(index: Int): Int = (this as java.lang.String).codePointAt(index)
@@ -123,8 +121,6 @@ public fun String.toLowerCase(locale: java.util.Locale): String = (this as java.
 
 public fun String.toUpperCase(locale: java.util.Locale): String = (this as java.lang.String).toUpperCase(locale)
 
-public fun CharSequence.charAt(index: Int): Char = (this as java.lang.CharSequence).charAt(index)
-
 public fun CharSequence.subSequence(start: Int, end: Int): CharSequence? = (this as java.lang.CharSequence).subSequence(start, end)
 
 public val CharSequence.size: Int
@@ -142,7 +138,6 @@ public fun String.toDouble(): Double = java.lang.Double.parseDouble(this)
 
 public fun String.toCharList(): List<Char> = toCharArray().toList()
 
-public fun CharSequence.get(index: Int): Char = charAt(index)
 public fun CharSequence.get(start: Int, end: Int): CharSequence? = subSequence(start, end)
 
 public fun String.toByteArray(charset: String): ByteArray = (this as java.lang.String).getBytes(charset)