Minor changes after code review

idea/resources/intentionDescriptions/LoopToCallChainIntention/after.kt.template

@@ -1,3 +1,3 @@
 fun foo(list: List<String>): String? {
-    <spot>return list.firstOrNull { s -> s.length > 0 }</spot>
+    <spot>return list.firstOrNull { it.length > 0 }</spot>
 }

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

@@ -66,7 +66,7 @@ interface SequenceTransformationMatcher {
 }
 
 class SequenceTransformationMatch(
-        val transformations: Collection<SequenceTransformation>,
+        val transformations: List<SequenceTransformation>,
         val newState: MatchingState
 ) {
     init {
@@ -82,5 +82,5 @@ interface ResultTransformationMatcher {
 
 class ResultTransformationMatch(
         val resultTransformation: ResultTransformation,
-        val sequenceTransformations: Collection<SequenceTransformation> = listOf()
+        val sequenceTransformations: List<SequenceTransformation> = listOf()
 )

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

@@ -94,7 +94,7 @@ fun match(loop: KtForExpression): ResultTransformationMatch? {
 fun convertLoop(loop: KtForExpression, matchResult: ResultTransformationMatch): KtExpression {
     val commentSaver = CommentSaver(matchResult.resultTransformation.commentSavingRange)
 
-    var callChain = matchResult.generateCallChain(loop)
+    val callChain = matchResult.generateCallChain(loop)
 
     val result = matchResult.resultTransformation.convertLoop(callChain)
 
@@ -158,11 +158,11 @@ private fun ResultTransformationMatch.generateCallChain(loop: KtForExpression):
     var sequenceTransformations = sequenceTransformations
     val last = sequenceTransformations.lastOrNull()
     var lastFilter: FilterOrMap? = null
-    var lastMap: FilterOrMap? = null //TODO
+    val lastMap: FilterOrMap? = null //TODO
     if (last is FilterTransformation && resultTransformation.canIncludeFilter) {
         val condition = if (last.isInverse) last.condition.negate() else last.condition
         lastFilter = FilterOrMap(condition, last.inputVariable)
-        sequenceTransformations = sequenceTransformations.take(sequenceTransformations.size - 1)
+        sequenceTransformations = sequenceTransformations.dropLast(1)
     }
 
     val lineBreak = if (sequenceTransformations.isNotEmpty()) "\n" else ""
@@ -170,20 +170,18 @@ private fun ResultTransformationMatch.generateCallChain(loop: KtForExpression):
     var callChain = loop.loopRange!!
 
     val psiFactory = KtPsiFactory(loop)
-    fun chainedCallGenerator(): ChainedCallGenerator {
+    val chainedCallGenerator = object : ChainedCallGenerator {
-        return object : ChainedCallGenerator {
+        override fun generate(pattern: String, vararg args: Any): KtExpression {
-            override fun generate(pattern: String, vararg args: Any): KtExpression {
+            val newPattern = "\$${args.size}$lineBreak.$pattern"
-                val newPattern = "\$${args.size}$lineBreak.$pattern"
+            return psiFactory.createExpressionByPattern(newPattern, *args, callChain)
-                return psiFactory.createExpressionByPattern(newPattern, *args, callChain)
-            }
         }
     }
 
     for (transformation in sequenceTransformations) {
-        callChain = transformation.generateCode(chainedCallGenerator())
+        callChain = transformation.generateCode(chainedCallGenerator)
     }
 
-    callChain = resultTransformation.generateCode(chainedCallGenerator(), lastFilter, lastMap)
+    callChain = resultTransformation.generateCode(chainedCallGenerator, lastFilter, lastMap)
     return callChain
 }
 

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

@@ -60,6 +60,15 @@ class FindAndAssignTransformation(
         return initialDeclaration
     }
 
+    /**
+     * Matches:
+     *     val variable = ...
+     *     for (...) {
+     *         ...
+     *         variable = ...
+     *         break
+     *     }
+     */
     object Matcher : ResultTransformationMatcher {
         override fun match(state: MatchingState): ResultTransformationMatch? {
             //TODO: pass indexVariable as null if not used

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

@@ -56,6 +56,14 @@ class FindAndReturnTransformation(
         return endReturn
     }
 
+    /**
+     * Matches:
+     *     for (...) {
+     *         ...
+     *         return ...
+     *     }
+     *     return ...
+     */
     object Matcher : ResultTransformationMatcher {
         override fun match(state: MatchingState): ResultTransformationMatch? {
             //TODO: pass indexVariable as null if not used

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

@@ -43,6 +43,21 @@ class FilterTransformation(
     }
 
     //TODO: merge subsequent filters
+    /**
+     * Matches:
+     *     for (...) {
+     *         if (<condition>) {
+     *             ...
+     *         }
+     *     }
+     *
+     * or
+     *
+     *     for (...) {
+     *         if (<condition>) continue
+     *         ...
+     *     }
+     */
     object Matcher : SequenceTransformationMatcher {
         override fun match(state: MatchingState): SequenceTransformationMatch? {
             if (state.indexVariable != null) return null //TODO?

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

@@ -42,6 +42,15 @@ class FlatMapTransformation(
         return chainedCallGenerator.generate("flatMap$0:'{}'", lambda)
     }
 
+    /**
+     * Matches:
+     *     for (...) {
+     *         ...
+     *         for (...) {
+     *             ...
+     *         }
+     *     }
+     */
     object Matcher : SequenceTransformationMatcher {
         override fun match(state: MatchingState): SequenceTransformationMatch? {
             if (state.indexVariable != null) return null

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

@@ -38,6 +38,13 @@ class MapTransformation(
         return chainedCallGenerator.generate("map$0:'{}'", lambda)
     }
 
+    /**
+     * Matches:
+     *     for (...) {
+     *         val v = ...
+     *         ...
+     *     }
+     */
     object Matcher : SequenceTransformationMatcher {
         override fun match(state: MatchingState): SequenceTransformationMatch? {
             if (state.indexVariable != null) return null //TODO?