Intrinsics for 'reversed': CharSequence.indices

#KT-21323 In Progress

compiler/backend/src/org/jetbrains/kotlin/codegen/range/CharSequenceIndicesRangeValue.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.codegen.range
 import org.jetbrains.kotlin.codegen.ExpressionCodegen
 import org.jetbrains.kotlin.codegen.StackValue
 import org.jetbrains.kotlin.codegen.generateCallReceiver
+import org.jetbrains.kotlin.codegen.range.forLoop.ForInDefinitelySafeSimpleProgressionLoopGenerator
 import org.jetbrains.kotlin.codegen.range.forLoop.ForInSimpleProgressionLoopGenerator
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.psi.KtForExpression
@@ -26,7 +27,9 @@ import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.org.objectweb.asm.Type
 
-class CharSequenceIndicesRangeValue(rangeCall: ResolvedCall<out CallableDescriptor>): PrimitiveNumberRangeIntrinsicRangeValue(rangeCall) {
+class CharSequenceIndicesRangeValue(rangeCall: ResolvedCall<out CallableDescriptor>) :
+        PrimitiveNumberRangeIntrinsicRangeValue(rangeCall), ReversableRangeValue {
+
     private val expectedReceiverType: KotlinType = ExpressionCodegen.getExpectedReceiverType(rangeCall)
 
     override fun getBoundedValue(codegen: ExpressionCodegen) =
@@ -43,4 +46,9 @@ class CharSequenceIndicesRangeValue(rangeCall: ResolvedCall<out CallableDescript
 
     override fun createForLoopGenerator(codegen: ExpressionCodegen, forExpression: KtForExpression) =
             ForInSimpleProgressionLoopGenerator.fromBoundedValueWithStep1(codegen, forExpression, getBoundedValue(codegen))
+
+    override fun createForInReversedLoopGenerator(codegen: ExpressionCodegen, forExpression: KtForExpression) =
+            ForInDefinitelySafeSimpleProgressionLoopGenerator.fromBoundedValueWithStepMinus1(
+                    codegen, forExpression, getBoundedValue(codegen)
+            )
 }

compiler/testData/codegen/box/ranges/forInReversed/forInReversedCharSequenceIndices.kt

@@ -0,0 +1,13 @@
+// WITH_RUNTIME
+import kotlin.test.*
+
+fun box(): String {
+    val cs = "1111"
+    var sum = 0
+    for (i in cs.indices.reversed()) {
+        sum = sum * 10 + i + cs[i].toInt() - '0'.toInt()
+    }
+    assertEquals(4321, sum)
+
+    return "OK"
+}

compiler/testData/codegen/bytecodeText/forLoop/forInReversed/forInReversedCharSequenceIndices.kt

@@ -0,0 +1,15 @@
+// WITH_RUNTIME
+import kotlin.test.*
+
+fun box(): String {
+    val cs = "1111"
+    var sum = 0
+    for (i in cs.indices.reversed()) {
+        sum = sum * 10 + i + cs[i].toInt() - '0'.toInt()
+    }
+    assertEquals(4321, sum)
+
+    return "OK"
+}
+
+// 0 reversed

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -15247,6 +15247,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 doTest(fileName);
             }
 
+            @TestMetadata("forInReversedCharSequenceIndices.kt")
+            public void testForInReversedCharSequenceIndices() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedCharSequenceIndices.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("forInReversedCollectionIndices.kt")
             public void testForInReversedCollectionIndices() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedCollectionIndices.kt");

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -15247,6 +15247,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("forInReversedCharSequenceIndices.kt")
+            public void testForInReversedCharSequenceIndices() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedCharSequenceIndices.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("forInReversedCollectionIndices.kt")
             public void testForInReversedCollectionIndices() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedCollectionIndices.kt");

compiler/tests/org/jetbrains/kotlin/codegen/BytecodeTextTestGenerated.java

@@ -1414,6 +1414,12 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("forInReversedCharSequenceIndices.kt")
+            public void testForInReversedCharSequenceIndices() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/forLoop/forInReversed/forInReversedCharSequenceIndices.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("forInReversedCollectionIndices.kt")
             public void testForInReversedCollectionIndices() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/forLoop/forInReversed/forInReversedCollectionIndices.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -15247,6 +15247,12 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 doTest(fileName);
             }
 
+            @TestMetadata("forInReversedCharSequenceIndices.kt")
+            public void testForInReversedCharSequenceIndices() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedCharSequenceIndices.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("forInReversedCollectionIndices.kt")
             public void testForInReversedCollectionIndices() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedCollectionIndices.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -16663,6 +16663,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("forInReversedCharSequenceIndices.kt")
+            public void testForInReversedCharSequenceIndices() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedCharSequenceIndices.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("forInReversedCollectionIndices.kt")
             public void testForInReversedCollectionIndices() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedCollectionIndices.kt");