Initial support for indexed transformations

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/LoopToCallChainIntention.kt

@@ -35,7 +35,7 @@ class LoopToCallChainIntention : SelfTargetingRangeIntention<KtForExpression>(
 ) {
     override fun applicabilityRange(element: KtForExpression): TextRange? {
         val match = match(element)
-        text = if (match != null) "Replace with '${match.buildPresentation()}'" else defaultText
+        text = if (match != null) "Replace with '${match.transformationMatch.buildPresentation()}'" else defaultText
         return if (match != null) element.forKeyword.textRange else null
     }
 

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/interfaces.kt

@@ -86,6 +86,9 @@ data class MatchingState(
         val innerLoop: KtForExpression,
         val statements: Collection<KtExpression>,
         val inputVariable: KtCallableDeclaration,
+        /**
+         * Matchers can assume that indexVariable is null if it's not used in the rest of the loop
+         */
         val indexVariable: KtCallableDeclaration?
 )
 
@@ -113,6 +116,8 @@ class SequenceTransformationMatch(
  */
 interface ResultTransformationMatcher {
     fun match(state: MatchingState): ResultTransformationMatch?
+
+    val indexVariableUsePossible: Boolean
 }
 
 class ResultTransformationMatch(

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/matchAndConvert.kt

@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.idea.intentions.loopToCallChain.sequence.FlatMapTran
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.sequence.MapTransformation
 import org.jetbrains.kotlin.idea.util.CommentSaver
 import org.jetbrains.kotlin.idea.util.getResolutionScope
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.anyDescendantOfType
 import org.jetbrains.kotlin.psi.psiUtil.forEachDescendantOfType
@@ -54,14 +55,21 @@ object MatcherRegistrar {
     )
 }
 
-fun match(loop: KtForExpression): ResultTransformationMatch? {
+data class MatchResult(
+        val sequenceExpression: KtExpression,
+        val transformationMatch: ResultTransformationMatch
+)
+
+fun match(loop: KtForExpression): MatchResult? {
+    val (inputVariable, indexVariable, sequenceExpression) = extractLoopData(loop) ?: return null
+
     val sequenceTransformations = ArrayList<SequenceTransformation>()
     var state = MatchingState(
             outerLoop = loop,
             innerLoop = loop,
             statements = listOf(loop.body ?: return null),
-            inputVariable = loop.loopParameter ?: return null,
-            indexVariable = null
+            inputVariable = inputVariable,
+            indexVariable = indexVariable
     )
 
     MatchLoop@
@@ -73,7 +81,14 @@ fun match(loop: KtForExpression): ResultTransformationMatch? {
 
         val inputVariableUsed = state.inputVariable.hasUsages(state.statements)
 
+        // drop index variable if it's not used anymore
+        if (state.indexVariable != null && !state.indexVariable!!.hasUsages(state.statements)) {
+            state = state.copy(indexVariable = null)
+        }
+
         for (matcher in MatcherRegistrar.resultMatchers) {
+            if (state.indexVariable != null && !matcher.indexVariableUsePossible) continue
+
             val match = matcher.match(state)
             if (match != null) {
                 if (!inputVariableUsed
@@ -85,6 +100,7 @@ fun match(loop: KtForExpression): ResultTransformationMatch? {
                 sequenceTransformations.addAll(match.sequenceTransformations)
                 return ResultTransformationMatch(match.resultTransformation, sequenceTransformations)
                         .let { mergeTransformations(it) }
+                        .let { MatchResult(sequenceExpression, it) }
                         .check { checkSmartCastsPreserved(loop, it) }
             }
         }
@@ -96,10 +112,16 @@ fun match(loop: KtForExpression): ResultTransformationMatch? {
                     return null
                 }
 
-                val newState = match.newState
+                var newState = match.newState
                 // check that old input variable is not needed anymore
                 if (state.inputVariable != newState.inputVariable && state.inputVariable.hasUsages(newState.statements)) return null
 
+                if (state.indexVariable != null && match.transformations.any { it.affectsIndex }) {
+                    // index variable is still needed but index in the new sequence is different
+                    if (state.indexVariable!!.hasUsages(newState.statements)) return null
+                    newState = newState.copy(indexVariable = null)
+                }
+
                 sequenceTransformations.addAll(match.transformations)
                 state = newState
                 continue@MatchLoop
@@ -111,19 +133,44 @@ fun match(loop: KtForExpression): ResultTransformationMatch? {
 }
 
 //TODO: offer to use of .asSequence() as an option
-fun convertLoop(loop: KtForExpression, matchResult: ResultTransformationMatch): KtExpression {
-    val commentSaver = CommentSaver(matchResult.resultTransformation.commentSavingRange)
+fun convertLoop(loop: KtForExpression, matchResult: MatchResult): KtExpression {
+    val resultTransformation = matchResult.transformationMatch.resultTransformation
+    val commentSaver = CommentSaver(resultTransformation.commentSavingRange)
 
     val callChain = matchResult.generateCallChain(loop)
 
-    val result = matchResult.resultTransformation.convertLoop(callChain)
+    val result = resultTransformation.convertLoop(callChain)
 
-    commentSaver.restore(matchResult.resultTransformation.commentRestoringRange(result))
+    commentSaver.restore(resultTransformation.commentRestoringRange(result))
 
     return result
 }
 
-private fun checkSmartCastsPreserved(loop: KtForExpression, matchResult: ResultTransformationMatch): Boolean {
+data class LoopData(
+        val inputVariable: KtCallableDeclaration,
+        val indexVariable: KtCallableDeclaration?,
+        val sequenceExpression: KtExpression)
+
+private fun extractLoopData(loop: KtForExpression): LoopData? {
+    val loopRange = loop.loopRange ?: return null
+
+    //TODO: recognize other patterns for loop with index
+    val destructuringParameter = loop.destructuringParameter
+    if (destructuringParameter != null && destructuringParameter.entries.size == 2) {
+        val qualifiedExpression = loopRange as? KtDotQualifiedExpression
+        if (qualifiedExpression != null) {
+            val call = qualifiedExpression.selectorExpression as? KtCallExpression
+            //TODO: check that it's the correct "withIndex"
+            if (call != null && call.calleeExpression.isSimpleName(Name.identifier("withIndex")) && call.valueArguments.isEmpty()) {
+                return LoopData(destructuringParameter.entries[1], destructuringParameter.entries[0], qualifiedExpression.receiverExpression)
+            }
+        }
+    }
+
+    return LoopData(loop.loopParameter ?: return null, null, loopRange)
+}
+
+private fun checkSmartCastsPreserved(loop: KtForExpression, matchResult: MatchResult): Boolean {
     val bindingContext = loop.analyze(BodyResolveMode.FULL)
 
     val SMARTCAST_KEY = Key<KotlinType>("SMARTCAST_KEY")
@@ -174,9 +221,9 @@ private fun checkSmartCastsPreserved(loop: KtForExpression, matchResult: ResultT
     }
 }
 
-private fun ResultTransformationMatch.generateCallChain(loop: KtForExpression): KtExpression {
-    var sequenceTransformations = sequenceTransformations
-    var resultTransformation = resultTransformation
+private fun MatchResult.generateCallChain(loop: KtForExpression): KtExpression {
+    var sequenceTransformations = transformationMatch.sequenceTransformations
+    var resultTransformation = transformationMatch.resultTransformation
     while(true) {
         val last = sequenceTransformations.lastOrNull() ?: break
         resultTransformation = resultTransformation.mergeWithPrevious(last) ?: break
@@ -186,7 +233,7 @@ private fun ResultTransformationMatch.generateCallChain(loop: KtForExpression):
     val chainCallCount = sequenceTransformations.sumBy { it.chainCallCount } + resultTransformation.chainCallCount
     val lineBreak = if (chainCallCount > 1) "\n" else ""
 
-    var callChain = loop.loopRange!!
+    var callChain = sequenceExpression
 
     val psiFactory = KtPsiFactory(loop)
     val chainedCallGenerator = object : ChainedCallGenerator {

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/result/AddToCollectionTransformation.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.idea.imports.importableFqName
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.*
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.sequence.FilterTransformation
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.sequence.FlatMapTransformation
+import org.jetbrains.kotlin.idea.intentions.loopToCallChain.sequence.MapIndexedTransformation
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.sequence.MapTransformation
 import org.jetbrains.kotlin.idea.util.IdeDescriptorRenderers
 import org.jetbrains.kotlin.name.FqName
@@ -33,14 +34,13 @@ import org.jetbrains.kotlin.renderer.render
 
 class AddToCollectionTransformation(
         loop: KtForExpression,
-        private val inputVariable: KtCallableDeclaration,
         private val targetCollection: KtExpression
 ) : ReplaceLoopResultTransformation(loop) {
 
     override fun mergeWithPrevious(previousTransformation: SequenceTransformation): ResultTransformation? {
         return when (previousTransformation) {
             is FilterTransformation -> {
-                FilterToTransformation.create(loop, inputVariable, targetCollection, previousTransformation.effectiveCondition()) //TODO: use filterNotTo?
+                FilterToTransformation.create(loop, previousTransformation.inputVariable, targetCollection, previousTransformation.effectiveCondition()) //TODO: use filterNotTo?
             }
 
             is MapTransformation -> {
@@ -80,10 +80,10 @@ class AddToCollectionTransformation(
      *     }
      */
     object Matcher : ResultTransformationMatcher {
-        override fun match(state: MatchingState): ResultTransformationMatch? {
-            //TODO: pass indexVariable as null if not used
-            if (state.indexVariable != null) return null
+        override val indexVariableUsePossible: Boolean
+            get() = true
 
+        override fun match(state: MatchingState): ResultTransformationMatch? {
             val statement = state.statements.singleOrNull() ?: return null
             //TODO: it can be implicit 'this' too
             val qualifiedExpression = statement as? KtDotQualifiedExpression ?: return null
@@ -95,16 +95,22 @@ class AddToCollectionTransformation(
             val argument = callExpression.valueArguments.singleOrNull() ?: return null
             val argumentValue = argument.getArgumentExpression() ?: return null
 
-            matchWithCollectionInitializationReplacement(state, targetCollection, argumentValue)
-                    ?.let { return it }
+            if (state.indexVariable == null) {
+                matchWithCollectionInitializationReplacement(state, targetCollection, argumentValue)
+                        ?.let { return it }
+            }
 
-            val transformation = if (argumentValue.isVariableReference(state.inputVariable)) {
-                AddToCollectionTransformation(state.outerLoop, state.inputVariable, targetCollection)
+            if (state.indexVariable == null && argumentValue.isVariableReference(state.inputVariable)) {
+                return ResultTransformationMatch(AddToCollectionTransformation(state.outerLoop, targetCollection))
+            }
+            else if (state.indexVariable != null) {
+                val mapIndexedTransformation = MapIndexedTransformation(state.outerLoop, state.inputVariable, state.indexVariable, argumentValue)
+                val addToCollectionTransformation = AddToCollectionTransformation(state.outerLoop, targetCollection)
+                return ResultTransformationMatch(addToCollectionTransformation, mapIndexedTransformation)
             }
             else {
-                MapToTransformation.create(state.outerLoop, state.inputVariable, targetCollection, argumentValue)
+                return ResultTransformationMatch(MapToTransformation.create(state.outerLoop, state.inputVariable, targetCollection, argumentValue))
             }
-            return ResultTransformationMatch(transformation)
         }
 
         private fun matchWithCollectionInitializationReplacement(

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/result/CountTransformation.kt

@@ -71,6 +71,9 @@ class CountTransformation(
      *     }
      */
     object Matcher : ResultTransformationMatcher {
+        override val indexVariableUsePossible: Boolean
+            get() = false
+
         override fun match(state: MatchingState): ResultTransformationMatch? {
             val statement = state.statements.singleOrNull() as? KtUnaryExpression ?: return null
             if (statement.operationToken != KtTokens.PLUSPLUS) return null

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/result/FindAndAssignTransformation.kt

@@ -71,10 +71,10 @@ class FindAndAssignTransformation(
      *     }
      */
     object Matcher : ResultTransformationMatcher {
-        override fun match(state: MatchingState): ResultTransformationMatch? {
-            //TODO: pass indexVariable as null if not used
-            if (state.indexVariable != null) return null
+        override val indexVariableUsePossible: Boolean
+            get() = false
 
+        override fun match(state: MatchingState): ResultTransformationMatch? {
             when (state.statements.size) {
                 1 -> {}
 

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/result/FindAndReturnTransformation.kt

@@ -70,10 +70,10 @@ class FindAndReturnTransformation(
      *     return ...
      */
     object Matcher : ResultTransformationMatcher {
-        override fun match(state: MatchingState): ResultTransformationMatch? {
-            //TODO: pass indexVariable as null if not used
-            if (state.indexVariable != null) return null
+        override val indexVariableUsePossible: Boolean
+            get() = false
 
+        override fun match(state: MatchingState): ResultTransformationMatch? {
             val returnInLoop = state.statements.singleOrNull() as? KtReturnExpression ?: return null
             val returnAfterLoop = state.outerLoop.nextStatement() as? KtReturnExpression ?: return null
             if (returnInLoop.getLabelName() != returnAfterLoop.getLabelName()) return null

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/sequence/FilterTransformation.kt

@@ -69,22 +69,20 @@ class FilterTransformation(
      */
     object Matcher : SequenceTransformationMatcher {
         override fun match(state: MatchingState): SequenceTransformationMatch? {
-            if (state.indexVariable != null) return null //TODO?
-
             val ifStatement = state.statements.firstOrNull() as? KtIfExpression ?: return null
             if (ifStatement.`else` != null) return null
             val condition = ifStatement.condition ?: return null
             val then = ifStatement.then ?: return null
 
             if (state.statements.size == 1) {
-                val transformation = createFilterTransformation(state.outerLoop, state.inputVariable, condition, isInverse = false)
+                val transformation = createFilterTransformation(state.outerLoop, state.inputVariable, state.indexVariable, condition, isInverse = false)
                 val newState = state.copy(statements = listOf(then))
                 return SequenceTransformationMatch(transformation, newState)
             }
             else {
                 val continueExpression = then.blockExpressionsOrSingle().singleOrNull() as? KtContinueExpression ?: return null
                 if (!continueExpression.isBreakOrContinueOfLoop(state.innerLoop)) return null
-                val transformation = createFilterTransformation(state.outerLoop, state.inputVariable, condition, isInverse = true)
+                val transformation = createFilterTransformation(state.outerLoop, state.inputVariable, state.indexVariable, condition, isInverse = true)
                 val newState = state.copy(statements = state.statements.drop(1))
                 return SequenceTransformationMatch(transformation, newState)
             }
@@ -94,11 +92,17 @@ class FilterTransformation(
         private fun createFilterTransformation(
                 loop: KtForExpression,
                 inputVariable: KtCallableDeclaration,
+                indexVariable: KtCallableDeclaration?,
                 condition: KtExpression,
-                isInverse: Boolean): SequenceTransformation {
+                isInverse: Boolean
+        ): SequenceTransformation {
 
             val effectiveCondition = if (isInverse) condition.negate() else condition
 
+            if (indexVariable != null && indexVariable.hasUsages(condition)) {
+                return FilterIndexedTransformation(loop, inputVariable, indexVariable, effectiveCondition)
+            }
+
             if (effectiveCondition is KtIsExpression
                 && !effectiveCondition.isNegated
                 && effectiveCondition.leftHandSide.isSimpleName(inputVariable.nameAsSafeName) // we cannot use isVariableReference here because expression can be non-physical
@@ -150,3 +154,25 @@ class FilterNotNullTransformation(override val loop: KtForExpression) : Sequence
         return chainedCallGenerator.generate("filterNotNull()")
     }
 }
+
+class FilterIndexedTransformation(
+        override val loop: KtForExpression,
+        val inputVariable: KtCallableDeclaration,
+        val indexVariable: KtCallableDeclaration,
+        val condition: KtExpression
+) : SequenceTransformation {
+
+    //TODO: how to handle multiple if's using index?
+
+    override val affectsIndex: Boolean
+        get() = true
+
+    override val presentation: String
+        get() = "filterIndexed{}"
+
+    override fun generateCode(chainedCallGenerator: ChainedCallGenerator): KtExpression {
+        val lambda = generateLambda(condition, indexVariable, inputVariable)
+        return chainedCallGenerator.generate("filterIndexed $0:'{}'", lambda)
+    }
+}
+

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/sequence/FlatMapTransformation.kt

@@ -20,9 +20,7 @@ import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.caches.resolve.getResolutionFacade
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.*
 import org.jetbrains.kotlin.idea.util.FuzzyType
-import org.jetbrains.kotlin.psi.KtCallableDeclaration
-import org.jetbrains.kotlin.psi.KtExpression
-import org.jetbrains.kotlin.psi.KtForExpression
+import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 
 class FlatMapTransformation(
@@ -53,8 +51,6 @@ class FlatMapTransformation(
      */
     object Matcher : SequenceTransformationMatcher {
         override fun match(state: MatchingState): SequenceTransformationMatch? {
-            if (state.indexVariable != null) return null
-
             val nestedLoop = state.statements.singleOrNull() as? KtForExpression ?: return null
 
             val transform = nestedLoop.loopRange ?: return null
@@ -65,8 +61,21 @@ class FlatMapTransformation(
             if (iterableType.checkIsSuperTypeOf(nestedSequenceType) == null) return null
 
             val nestedLoopBody = nestedLoop.body ?: return null
-
             val newWorkingVariable = nestedLoop.loopParameter ?: return null
+
+            if (state.indexVariable != null && state.indexVariable.hasUsages(transform)) {
+                // if nested loop range uses index, convert to "mapIndexed {...}.flatMap { it }"
+                val mapIndexedTransformation = MapIndexedTransformation(state.outerLoop, state.inputVariable, state.indexVariable, transform)
+                val inputVarExpression = KtPsiFactory(nestedLoop).createExpressionByPattern("$0", state.inputVariable.nameAsSafeName)
+                val flatMapTransformation = FlatMapTransformation(state.outerLoop, state.inputVariable, inputVarExpression)
+                val newState = state.copy(
+                        innerLoop = nestedLoop,
+                        statements = listOf(nestedLoopBody),
+                        inputVariable = newWorkingVariable
+                )
+                return SequenceTransformationMatch(listOf(mapIndexedTransformation, flatMapTransformation), newState)
+            }
+
             val transformation = FlatMapTransformation(state.outerLoop, state.inputVariable, transform)
             val newState = state.copy(
                     innerLoop = nestedLoop,

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/sequence/MapTransformation.kt

@@ -48,16 +48,36 @@ class MapTransformation(
      */
     object Matcher : SequenceTransformationMatcher {
         override fun match(state: MatchingState): SequenceTransformationMatch? {
-            if (state.indexVariable != null) return null //TODO?
-
             val declaration = state.statements.firstOrNull() as? KtProperty ?: return null //TODO: support multi-variables
             val initializer = declaration.initializer ?: return null
             if (declaration.hasWriteUsages()) return null
             val restStatements = state.statements.drop(1)
 
-            val transformation = MapTransformation(state.outerLoop, state.inputVariable, initializer)
+            val transformation = if (state.indexVariable != null && state.indexVariable.hasUsages(initializer))
+                MapIndexedTransformation(state.outerLoop, state.inputVariable, state.indexVariable, initializer)
+            else
+                MapTransformation(state.outerLoop, state.inputVariable, initializer)
             val newState = state.copy(statements = restStatements, inputVariable = declaration)
             return SequenceTransformationMatch(transformation, newState)
         }
     }
-}
+}
+
+class MapIndexedTransformation(
+        override val loop: KtForExpression,
+        val inputVariable: KtCallableDeclaration,
+        val indexVariable: KtCallableDeclaration,
+        val mapping: KtExpression
+) : SequenceTransformation {
+
+    override val affectsIndex: Boolean
+        get() = false
+
+    override val presentation: String
+        get() = "mapIndexed{}"
+
+    override fun generateCode(chainedCallGenerator: ChainedCallGenerator): KtExpression {
+        val lambda = generateLambda(mapping, indexVariable, inputVariable)
+        return chainedCallGenerator.generate("mapIndexed $0:'{}'", lambda)
+    }
+}

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/utils.kt

@@ -81,6 +81,25 @@ fun generateLambda(inputVariable: KtCallableDeclaration, expression: KtExpressio
     return psiFactory.createExpressionByPattern("{ $0 }", lambdaExpression.bodyExpression!!) as KtLambdaExpression
 }
 
+fun generateLambda(expression: KtExpression, vararg inputVariables: KtCallableDeclaration): KtLambdaExpression {
+    return KtPsiFactory(expression).buildExpression {
+        appendFixedText("{")
+
+        for ((index, variable) in inputVariables.withIndex()) {
+            if (index > 0) {
+                appendFixedText(",")
+            }
+            appendName(variable.nameAsSafeName)
+        }
+
+        appendFixedText("->")
+
+        appendExpression(expression)
+
+        appendFixedText("}")
+    } as KtLambdaExpression
+}
+
 fun KtExpression?.isTrueConstant()
         = this != null && node?.elementType == KtNodeTypes.BOOLEAN_CONSTANT && text == "true"
 
@@ -100,12 +119,14 @@ fun KtCallableDeclaration.hasUsages(inElement: KtElement): Boolean {
 }
 
 fun KtCallableDeclaration.hasUsages(inElements: Collection<KtElement>): Boolean {
+    assert(this.isPhysical)
     // TODO: it's a temporary workaround about strange dead-lock when running inspections
     return inElements.any { ReferencesSearch.search(this, LocalSearchScope(it)).any() }
 //    return ReferencesSearch.search(this, LocalSearchScope(inElements.toTypedArray())).any()
 }
 
 fun KtProperty.hasWriteUsages(): Boolean {
+    assert(this.isPhysical)
     if (!isVar) return false
     return ReferencesSearch.search(this, useScope).any {
         (it as? KtSimpleNameReference)?.element?.readWriteAccess(useResolveForReadWrite = true)?.isWrite == true

idea/testData/intentions/loopToCallChain/any_indexNeeded.kt

@@ -0,0 +1,11 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'filterIndexed{}.any()'"
+fun foo(list: List<String>) {
+    var found = false
+    <caret>for ((index, s) in list.withIndex()) {
+        if (s.length > index) {
+            found = true
+            break
+        }
+    }
+}

idea/testData/intentions/loopToCallChain/any_indexNeeded.kt.after

@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'filterIndexed{}.any()'"
+fun foo(list: List<String>) {
+    val <caret>found = list
+            .filterIndexed { index, s -> s.length > index }
+            .any()
+}

idea/testData/intentions/loopToCallChain/filterIndexed.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'filterIndexed{}.firstOrNull()'"
+fun foo(list: List<String>): String? {
+    <caret>for ((index, s) in list.withIndex()) {
+        if (s.length > index) {
+            return s
+        }
+    }
+    return null
+}

idea/testData/intentions/loopToCallChain/filterIndexed.kt.after

@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'filterIndexed{}.firstOrNull()'"
+fun foo(list: List<String>): String? {
+    <caret>return list
+            .filterIndexed { index, s -> s.length > index }
+            .firstOrNull()
+}

idea/testData/intentions/loopToCallChain/flatMap_indexUsed.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'mapIndexed{}.flatMap{}.firstOrNull{}'"
+fun foo(list: List<String>): String? {
+    <caret>for ((index, s) in list.withIndex()) {
+        for (line in s.lines().take(index)) {
+            if (line.isNotBlank()) return line
+        }
+    }
+    return null
+}

idea/testData/intentions/loopToCallChain/flatMap_indexUsed.kt.after

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'mapIndexed{}.flatMap{}.firstOrNull{}'"
+fun foo(list: List<String>): String? {
+    <caret>return list
+            .mapIndexed { index, s -> s.lines().take(index) }
+            .flatMap { it }
+            .firstOrNull { it.isNotBlank() }
+}

idea/testData/intentions/loopToCallChain/mapAndFilterIndexed.kt

@@ -0,0 +1,11 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'map{}.filterIndexed{}.firstOrNull()'"
+fun foo(list: List<String>): Int? {
+    <caret>for ((index, s) in list.withIndex()) {
+        val l = s.length
+        if (l > index) {
+            return l
+        }
+    }
+    return null
+}

idea/testData/intentions/loopToCallChain/mapAndFilterIndexed.kt.after

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'map{}.filterIndexed{}.firstOrNull()'"
+fun foo(list: List<String>): Int? {
+    <caret>return list
+            .map { it.length }
+            .filterIndexed { index, l -> l > index }
+            .firstOrNull()
+}

idea/testData/intentions/loopToCallChain/mapIndexed.kt

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'mapIndexed{}.firstOrNull{}'"
+fun foo(list: List<String>): Int? {
+    <caret>for ((index, s) in list.withIndex()) {
+        val x = s.length * index
+        if (x > 0) return x
+    }
+    return null
+}

idea/testData/intentions/loopToCallChain/mapIndexed.kt.after

@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'mapIndexed{}.firstOrNull{}'"
+fun foo(list: List<String>): Int? {
+    <caret>return list
+            .mapIndexed { index, s -> s.length * index }
+            .firstOrNull { it > 0 }
+}

idea/testData/intentions/loopToCallChain/mapIndexed_twice.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'mapIndexed{}.mapIndexed{}.firstOrNull{}'"
+fun foo(list: List<String>): Int? {
+    <caret>for ((index, s) in list.withIndex()) {
+        val x = s.length * index
+        val y = x + index
+        if (y > 0) return y
+    }
+    return null
+}

idea/testData/intentions/loopToCallChain/mapIndexed_twice.kt.after

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'mapIndexed{}.mapIndexed{}.firstOrNull{}'"
+fun foo(list: List<String>): Int? {
+    <caret>return list
+            .mapIndexed { index, s -> s.length * index }
+            .mapIndexed { index, x -> x + index }
+            .firstOrNull { it > 0 }
+}

idea/testData/intentions/loopToCallChain/mapTo_indexUsed.kt

@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with '+= mapIndexed{}'"
+fun foo(list: List<String>, target: MutableList<Int>) {
+    <caret>for ((index, s) in list.withIndex()) {
+        target.add(s.hashCode() * index)
+    }
+}

idea/testData/intentions/loopToCallChain/mapTo_indexUsed.kt.after

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with '+= mapIndexed{}'"
+fun foo(list: List<String>, target: MutableList<Int>) {
+    <caret>target += list.mapIndexed { index, s -> s.hashCode() * index }
+}

idea/testData/intentions/loopToCallChain/mapUsesOldIndexAfterFilter.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+// IS_APPLICABLE: false
+fun foo(list: List<String>): Int? {
+    <caret>for ((index, s) in list.withIndex()) {
+        if (s.isBlank()) continue
+        val x = s.length * index
+        if (x > 1000) return x
+    }
+    return null
+}