Uast: explicitly expose implicit Lambda parameters

plugins/uast-kotlin/src/org/jetbrains/uast/kotlin/expressions/KotlinULambdaExpression.kt

@@ -18,11 +18,13 @@ package org.jetbrains.uast.kotlin
 
 import com.intellij.psi.PsiType
 import org.jetbrains.kotlin.psi.KtBlockExpression
-import org.jetbrains.kotlin.psi.KtExpression
 import org.jetbrains.kotlin.psi.KtLambdaExpression
+import org.jetbrains.kotlin.resolve.BindingContext.FUNCTION
 import org.jetbrains.kotlin.resolve.bindingContextUtil.isUsedAsResultOfLambda
+import org.jetbrains.kotlin.resolve.calls.components.isVararg
 import org.jetbrains.uast.*
 import org.jetbrains.uast.kotlin.psi.UastKotlinPsiParameter
+import org.jetbrains.uast.kotlin.psi.UastKotlinPsiParameterBase
 
 class KotlinULambdaExpression(
         override val sourcePsi: KtLambdaExpression,
@@ -58,9 +60,23 @@ class KotlinULambdaExpression(
     }
 
     override val valueParameters by lz {
-        sourcePsi.valueParameters.mapIndexed { i, p ->
+
+        val explicitParameters = sourcePsi.valueParameters.mapIndexed { i, p ->
             KotlinUParameter(UastKotlinPsiParameter.create(p, sourcePsi, this, i), p, this)
         }
+        if (explicitParameters.isNotEmpty()) return@lz explicitParameters
+
+        val functionDescriptor = sourcePsi.analyze()[FUNCTION, sourcePsi.functionLiteral] ?: return@lz emptyList()
+        functionDescriptor.valueParameters.mapIndexed { i, p ->
+            KotlinUParameter(
+                UastKotlinPsiParameterBase(
+                    p.name.asString(),
+                    p.type.toPsiType(this, sourcePsi, false),
+                    sourcePsi, sourcePsi, sourcePsi.language, p.isVararg, null
+                ),
+                null, this
+            )
+        }
     }
     
     override fun asRenderString(): String {

plugins/uast-kotlin/testData/LambdaReturn.log.txt

@@ -83,6 +83,7 @@ UFile (package = org.jetbrains.uast.kotlin)
                     UIdentifier (Identifier (bar))
                     USimpleNameReferenceExpression (identifier = bar, resolvesTo = null)
                     ULambdaExpression
+                        UParameter (name = it)
                         UBlockExpression
                             UIfExpression
                                 UBinaryExpression (operator = >)

plugins/uast-kotlin/testData/LambdaReturn.render.txt

@@ -24,7 +24,8 @@ public final class LambdaReturnKt {
         var lam5: kotlin.jvm.functions.Function1<? super java.lang.Integer,? extends java.lang.String> = fun (@org.jetbrains.annotations.NotNull var a: int) {
                 return "a" + a
         }
-        bar({
+        bar({ var it: int ->
+
             if (it > 5) return
             var b: int = 1
             return it + b

plugins/uast-kotlin/testData/Lambdas.log.txt

@@ -13,6 +13,7 @@ UFile (package = )
                         UIdentifier (Identifier (filter))
                         USimpleNameReferenceExpression (identifier = filter, resolvesTo = null)
                         ULambdaExpression
+                            UParameter (name = it)
                             UBlockExpression
                                 UReturnExpression
                                     UQualifiedReferenceExpression

plugins/uast-kotlin/testData/Lambdas.render.txt

@@ -2,7 +2,8 @@ import java.util.stream.Stream
 
 public final class LambdasKt {
     public static final fun foo() : void {
-        Stream.empty().filter({
+        Stream.empty().filter({ var it: java.lang.String ->
+
             return it.isEmpty()
         })
     }

plugins/uast-kotlin/testData/TypeReferences.log.txt

@@ -50,6 +50,7 @@ UFile (package = )
                                 UIdentifier (Identifier (map))
                                 USimpleNameReferenceExpression (identifier = map, resolvesTo = null)
                                 ULambdaExpression
+                                    UParameter (name = it)
                                     UBlockExpression
                                         UReturnExpression
                                             UQualifiedReferenceExpression

plugins/uast-kotlin/testData/TypeReferences.render.txt

@@ -12,7 +12,8 @@ public final class TypeReferencesKt {
             if (var708e23eb != null) var708e23eb else return
         }
         var tl: java.util.List<? extends T> = listOf(at)
-        var tsl: java.util.List<? extends java.lang.String> = tl.map({
+        var tsl: java.util.List<? extends java.lang.String> = tl.map({ var it: T ->
+
             return it.toString()
         })
         var lls: java.util.List<? extends java.util.List<? extends java.lang.String>>