Add CharSequence.subSequence

This is done primarily for JVM interoperability, otherwise it's impossible to
inherit from CharSequence there. On JS subSequence at the moment just invokes
substring.

 #KT-5956 Fixed

compiler/testData/builtin-classes.txt

@@ -296,6 +296,7 @@ public final class CharRange : kotlin.Range<kotlin.Char>, kotlin.Progression<kot
 public trait CharSequence {
     public abstract fun charAt(/*0*/ index: kotlin.Int): kotlin.Char
     public abstract fun length(): kotlin.Int
+    public abstract fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence
 }
 
 public trait Cloneable {
@@ -1433,6 +1434,7 @@ public final class String : kotlin.Comparable<kotlin.String>, kotlin.CharSequenc
     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
+    public open override /*1*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence
 }
 
 public open class Throwable {

compiler/testData/codegen/box/strings/kt5956.kt

@@ -0,0 +1,15 @@
+// KT-5956 java.lang.AbstractMethodError: test.Thing.subSequence(II)Ljava/lang/CharSequence
+
+class Thing(val delegate: CharSequence) : CharSequence {
+    override fun charAt(index: Int): Char {
+        throw UnsupportedOperationException()
+    }
+    override fun length(): Int = 0
+    override fun subSequence(start: Int, end: Int) = delegate.subSequence(start, end)
+}
+
+fun box(): String {
+    val txt = Thing("hello there")
+    val s = txt.subSequence(0, 1)
+    return if ("$s" == "h") "OK" else "Fail: $s"
+}

compiler/testData/diagnostics/tests/MergePackagesWithJava.txt

@@ -4508,7 +4508,7 @@ package java {
             public open fun reverse(): java.lang.AbstractStringBuilder!
             public open fun setCharAt(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Char): kotlin.Unit
             public open fun setLength(/*0*/ p0: kotlin.Int): kotlin.Unit
-            public open fun subSequence(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.CharSequence!
+            public open override /*1*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
             public open fun substring(/*0*/ p0: kotlin.Int): kotlin.String!
             public open fun substring(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.String!
             public abstract override /*2*/ fun toString(): kotlin.String!
@@ -8017,7 +8017,7 @@ package java {
             public open fun split(/*0*/ regex: kotlin.String!, /*1*/ limit: kotlin.Int): kotlin.Array<(out) kotlin.String!>!
             public open fun startsWith(/*0*/ p0: kotlin.String!): kotlin.Boolean
             public open fun startsWith(/*0*/ p0: kotlin.String!, /*1*/ p1: kotlin.Int): kotlin.Boolean
-            public open fun subSequence(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.CharSequence!
+            public open override /*1*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
             public open fun substring(/*0*/ p0: kotlin.Int): kotlin.String!
             public open fun substring(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.String!
             public open fun toCharArray(): kotlin.CharArray!
@@ -8120,7 +8120,7 @@ package java {
             public open override /*1*/ fun reverse(): java.lang.StringBuffer!
             public open override /*1*/ fun setCharAt(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Char): kotlin.Unit
             public open override /*1*/ fun setLength(/*0*/ p0: kotlin.Int): kotlin.Unit
-            public open override /*1*/ fun subSequence(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.CharSequence!
+            public open override /*2*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
             public open override /*1*/ fun substring(/*0*/ p0: kotlin.Int): kotlin.String!
             public open override /*1*/ fun substring(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.String!
             public open override /*3*/ fun toString(): kotlin.String!
@@ -8191,7 +8191,7 @@ package java {
             public open override /*1*/ fun reverse(): java.lang.StringBuilder!
             public open override /*1*/ /*fake_override*/ fun setCharAt(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Char): kotlin.Unit
             public open override /*1*/ /*fake_override*/ fun setLength(/*0*/ p0: kotlin.Int): kotlin.Unit
-            public open override /*1*/ /*fake_override*/ fun subSequence(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.CharSequence!
+            public open override /*2*/ /*fake_override*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence
             public open override /*1*/ /*fake_override*/ fun substring(/*0*/ p0: kotlin.Int): kotlin.String!
             public open override /*1*/ /*fake_override*/ fun substring(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.String!
             public open override /*3*/ fun toString(): kotlin.String!

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

@@ -18,5 +18,6 @@ internal final class Sub : kotlin.CharSequence {
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public abstract override /*1*/ /*fake_override*/ fun length(): kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }

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

@@ -6,7 +6,7 @@ public open class C : kotlin.CharSequence {
     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 subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
     java.lang.Override() public open override /*1*/ fun toString(): kotlin.String!
 }
 

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

@@ -4513,7 +4513,7 @@ package java {
             public open fun reverse(): java.lang.AbstractStringBuilder!
             public open fun setCharAt(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Char): kotlin.Unit
             public open fun setLength(/*0*/ p0: kotlin.Int): kotlin.Unit
-            public open fun subSequence(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.CharSequence!
+            public open override /*1*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
             public open fun substring(/*0*/ p0: kotlin.Int): kotlin.String!
             public open fun substring(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.String!
             public abstract override /*2*/ fun toString(): kotlin.String!
@@ -8022,7 +8022,7 @@ package java {
             public open fun split(/*0*/ regex: kotlin.String!, /*1*/ limit: kotlin.Int): kotlin.Array<(out) kotlin.String!>!
             public open fun startsWith(/*0*/ p0: kotlin.String!): kotlin.Boolean
             public open fun startsWith(/*0*/ p0: kotlin.String!, /*1*/ p1: kotlin.Int): kotlin.Boolean
-            public open fun subSequence(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.CharSequence!
+            public open override /*1*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
             public open fun substring(/*0*/ p0: kotlin.Int): kotlin.String!
             public open fun substring(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.String!
             public open fun toCharArray(): kotlin.CharArray!
@@ -8125,7 +8125,7 @@ package java {
             public open override /*1*/ fun reverse(): java.lang.StringBuffer!
             public open override /*1*/ fun setCharAt(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Char): kotlin.Unit
             public open override /*1*/ fun setLength(/*0*/ p0: kotlin.Int): kotlin.Unit
-            public open override /*1*/ fun subSequence(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.CharSequence!
+            public open override /*2*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence!
             public open override /*1*/ fun substring(/*0*/ p0: kotlin.Int): kotlin.String!
             public open override /*1*/ fun substring(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.String!
             public open override /*3*/ fun toString(): kotlin.String!
@@ -8196,7 +8196,7 @@ package java {
             public open override /*1*/ fun reverse(): java.lang.StringBuilder!
             public open override /*1*/ /*fake_override*/ fun setCharAt(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Char): kotlin.Unit
             public open override /*1*/ /*fake_override*/ fun setLength(/*0*/ p0: kotlin.Int): kotlin.Unit
-            public open override /*1*/ /*fake_override*/ fun subSequence(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.CharSequence!
+            public open override /*2*/ /*fake_override*/ fun subSequence(/*0*/ start: kotlin.Int, /*1*/ end: kotlin.Int): kotlin.CharSequence
             public open override /*1*/ /*fake_override*/ fun substring(/*0*/ p0: kotlin.Int): kotlin.String!
             public open override /*1*/ /*fake_override*/ fun substring(/*0*/ p0: kotlin.Int, /*1*/ p1: kotlin.Int): kotlin.String!
             public open override /*3*/ fun toString(): kotlin.String!

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

@@ -6298,6 +6298,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("kt5956.kt")
+        public void testKt5956() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/strings/kt5956.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt881.kt")
         public void testKt881() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/strings/kt881.kt");

core/builtins/native/kotlin/CharSequence.kt

@@ -20,4 +20,6 @@ public trait CharSequence {
     public fun length(): Int
 
     public fun charAt(index: Int): Char
+
+    public fun subSequence(start: Int, end: Int): CharSequence
 }

core/builtins/native/kotlin/String.kt

@@ -25,5 +25,7 @@ public class String : Comparable<String>, CharSequence {
 
     public override fun charAt(index: Int): Char
 
+    public override fun subSequence(start: Int, end: Int): CharSequence
+
     public override fun compareTo(other: String): Int
 }

generators/src/org/jetbrains/jet/generators/evaluate/GenerateOperationsMap.kt

@@ -22,13 +22,12 @@ import com.intellij.openapi.util.io.FileUtil
 import org.jetbrains.jet.utils.Printer
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns
 import org.jetbrains.jet.lang.descriptors.ClassDescriptor
-import java.util.Collections
 import org.jetbrains.jet.lang.descriptors.FunctionDescriptor
 import org.jetbrains.jet.lang.types.TypeUtils
 import org.jetbrains.jet.lang.types.JetType
 
 val DEST_FILE: File = File("compiler/frontend/src/org/jetbrains/jet/lang/evaluate/OperationsMapGenerated.kt")
-private val EXCLUDED_FUNCTIONS = listOf("rangeTo", "hashCode", "inc", "dec")
+private val EXCLUDED_FUNCTIONS = listOf("rangeTo", "hashCode", "inc", "dec", "subSequence")
 
 fun main(args: Array<String>) {
     GeneratorsFileUtil.writeFileIfContentChanged(DEST_FILE, generate())
@@ -56,7 +55,7 @@ fun generate(): String {
 
     for (descriptor in allPrimitiveTypes + builtIns.getString()) {
         [suppress("UNCHECKED_CAST")]
-        val functions = descriptor.getMemberScope(Collections.emptyList()).getDescriptors()
+        val functions = descriptor.getMemberScope(listOf()).getDescriptors()
                 .filter { it is FunctionDescriptor && !EXCLUDED_FUNCTIONS.contains(it.getName().asString()) } as List<FunctionDescriptor>
 
         for (function in functions) {
@@ -82,7 +81,7 @@ fun generate(): String {
         val (funcName, parameters) = unaryOperationsMapIterator.next()
         p.println(
                 "unaryOperation(",
-                parameters.map { it.asSrting() }.makeString(", "),
+                parameters.map { it.asString() }.joinToString(", "),
                 ", ",
                 "\"$funcName\"",
                 ", { a -> a.${funcName}() }, ",
@@ -105,7 +104,7 @@ fun generate(): String {
         val (funcName, parameters) = binaryOperationsMapIterator.next()
         p.println(
                 "binaryOperation(",
-                parameters.map { it.asSrting() }.makeString(", "),
+                parameters.map { it.asString() }.joinToString(", "),
                 ", ",
                 "\"$funcName\"",
                 ", { a, b -> a.${funcName}(b) }, ",
@@ -168,4 +167,4 @@ private fun FunctionDescriptor.getParametersTypes(): List<JetType> {
     return list
 }
 
-private fun JetType.asSrting(): String = getConstructor().getDeclarationDescriptor()!!.getName().asString().toUpperCase()
+private fun JetType.asString(): String = getConstructor().getDeclarationDescriptor()!!.getName().asString().toUpperCase()

js/js.tests/test/org/jetbrains/k2js/test/semantics/StringTest.java

@@ -90,4 +90,8 @@ public final class StringTest extends AbstractExpressionTest {
     public void testNullableTypeInStringTemplate() throws Exception {
         checkFooBoxIsOk();
     }
+
+    public void testSubSequence() throws Exception {
+        checkFooBoxIsOk();
+    }
 }

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

@@ -30,6 +30,7 @@ public final class StringOperationFIF extends CompositeFIF {
         // 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", "CharSequence", "subSequence").checkOverridden(), new BuiltInFunctionIntrinsic("substring"));
         add(pattern("kotlin.js", "isEmpty").isExtensionOf("kotlin.CharSequence"), IS_EMPTY_INTRINSIC);
     }
 }

js/js.translator/testData/expression/string/cases/subSequence.kt

@@ -0,0 +1,15 @@
+package foo
+
+fun box(): String {
+    val kotlin: String = "kotlin"
+
+    if (kotlin.subSequence(0, kotlin.length()) != kotlin) return "Fail 0"
+
+    val kot: CharSequence = kotlin.subSequence(0, 3)
+    if (kot.toString() != "kot") return "Fail 1: $kot"
+
+    val tlin = (kotlin : CharSequence).subSequence(2, 6)
+    if (tlin.toString() != "tlin") return "Fail 2: $tlin"
+
+    return "OK"
+}

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

@@ -115,14 +115,10 @@ public fun String.regionMatches(toffset: Int, other: String, ooffset: Int, len:
 
 public fun String.replace(target: CharSequence, replacement: CharSequence): String = (this as java.lang.String).replace(target, replacement)
 
-public fun String.subSequence(beginIndex: Int, endIndex: Int): CharSequence = (this as java.lang.String).subSequence(beginIndex, endIndex)
-
 public fun String.toLowerCase(locale: java.util.Locale): String = (this as java.lang.String).toLowerCase(locale)
 
 public fun String.toUpperCase(locale: java.util.Locale): String = (this as java.lang.String).toUpperCase(locale)
 
-public fun CharSequence.subSequence(start: Int, end: Int): CharSequence? = (this as java.lang.CharSequence).subSequence(start, end)
-
 public val CharSequence.size: Int
     get() = this.length
 
@@ -138,7 +134,7 @@ public fun String.toDouble(): Double = java.lang.Double.parseDouble(this)
 
 public fun String.toCharList(): List<Char> = toCharArray().toList()
 
-public fun CharSequence.get(start: Int, end: Int): CharSequence? = subSequence(start, end)
+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)
 public fun String.toByteArray(charset: Charset = Charsets.UTF_8): ByteArray = (this as java.lang.String).getBytes(charset)
@@ -156,7 +152,7 @@ public fun String.getBytes(charset: String): ByteArray = (this as java.lang.Stri
  * Returns a subsequence specified by given range.
  */
 public fun CharSequence.slice(range: IntRange): CharSequence {
-    return subSequence(range.start, range.end + 1)!! // inclusive
+    return subSequence(range.start, range.end + 1) // inclusive
 }
 
 /**