FIR: partial function type resolve + some rendering fixes

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirTypeResolveTransformer.kt

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.name.FqName
 
 open class FirTypeResolveTransformer : FirTransformer<Nothing?>() {
     override fun <E : FirElement> transformElement(element: E, data: Nothing?): CompositeTransformResult<E> {
+        @Suppress("UNCHECKED_CAST")
         return (element.transformChildren(this, data) as E).compose()
     }
 
@@ -112,6 +113,10 @@ open class FirTypeResolveTransformer : FirTransformer<Nothing?>() {
         return transformType(type, typeResolver.resolveType(type, scope, position = FirPosition.OTHER))
     }
 
+    override fun transformFunctionType(functionType: FirFunctionType, data: Nothing?): CompositeTransformResult<FirType> {
+        return (functionType.transformChildren(this, data) as FirType).compose()
+    }
+
     private fun transformType(type: FirType, resolvedType: ConeKotlinType): CompositeTransformResult<FirType> {
         return FirResolvedTypeImpl(
             type.session,

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirRenderer.kt

@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.fir.symbols.ConeSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.visitors.FirVisitorVoid
+import org.jetbrains.kotlin.name.SpecialNames
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.utils.Printer
 
@@ -92,6 +93,7 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
         visitMemberDeclaration(callableMember)
         val receiverType = callableMember.receiverType
         if (receiverType != null) {
+            print(" ")
             receiverType.accept(this)
             print(".")
         }
@@ -324,7 +326,9 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
         if (valueParameter.isVararg) {
             print("vararg ")
         }
-        print(valueParameter.name.toString() + ": ")
+        if (valueParameter.name != SpecialNames.NO_NAME_PROVIDED) {
+            print(valueParameter.name.toString() + ": ")
+        }
         valueParameter.returnType.accept(this)
         valueParameter.defaultValue?.let {
             print(" = ")
@@ -399,7 +403,7 @@ class FirRenderer(builder: StringBuilder) : FirVisitorVoid() {
             print(".")
         }
         functionType.valueParameters.renderParameters()
-        print(": ")
+        print(" -> ")
         functionType.returnType.accept(this)
         print(" )")
         visitTypeWithNullability(functionType)

compiler/testData/fir/rawBuilder/declarations/functionTypes.txt

@@ -1,9 +1,9 @@
 FILE: functionTypes.kt
-    <T> public? final? function simpleRun(f: ( (<no name provided>: T): Unit )): Unit {
+    <T> public? final? function simpleRun(f: ( (T) -> Unit )): Unit {
         STUB
     }
-    <T, R> public? final? function simpleMapList<T>.(f: ( (<no name provided>: T): R )): R {
+    <T, R> public? final? function simpleMap List<T>.(f: ( (T) -> R )): R {
     }
-    <T> public? final? function simpleWith(t: T, f: ( T.(): Unit )): Unit {
+    <T> public? final? function simpleWith(t: T, f: ( T.() -> Unit )): Unit {
         STUB
     }

compiler/testData/fir/rawBuilder/declarations/genericFunctions.txt

@@ -1,7 +1,7 @@
 FILE: genericFunctions.kt
     public? abstract interface Any() {
     }
-    <reified T : Any> public? final? inline function safeAsAny.(): T? {
+    <reified T : Any> public? final? inline function safeAs Any.(): T? {
         STUB
     }
     public? abstract class Summator() {

compiler/testData/fir/resolve/builtins/lists.txt

@@ -3,7 +3,7 @@ FILE: lists.kt
     }
     public? abstract class MyMutableStringList() : R/kotlin/collections/MutableList<kotlin/String>/ {
     }
-    public? final? function convertR/kotlin/collections/List<kotlin/String>/.(): R/MyStringList/ {
+    public? final? function convert R/kotlin/collections/List<kotlin/String>/.(): R/MyStringList/ {
         STUB
     }
     public? final? function ret(l: R/kotlin/collections/MutableList<kotlin/String>/): R/MyMutableStringList/ {

compiler/testData/fir/resolve/functionTypes.kt

@@ -0,0 +1,8 @@
+fun <T> simpleRun(f: (T) -> Unit): Unit = f()
+
+fun <T, R> List<T>.simpleMap(f: (T) -> R): R {
+
+}
+
+fun <T> simpleWith(t: T, f: T.() -> Unit): Unit = t.f()
+

compiler/testData/fir/resolve/functionTypes.txt

@@ -0,0 +1,9 @@
+FILE: functionTypes.kt
+    <T> public? final? function simpleRun(f: ( (R/T/) -> R/kotlin/Unit/ )): R/kotlin/Unit/ {
+        STUB
+    }
+    <T, R> public? final? function simpleMap R/kotlin/collections/List<T>/.(f: ( (R/T/) -> R/R/ )): R/R/ {
+    }
+    <T> public? final? function simpleWith(t: R/T/, f: ( R/T/.() -> R/kotlin/Unit/ )): R/kotlin/Unit/ {
+        STUB
+    }

compiler/testData/fir/resolve/genericFunctions.txt

@@ -1,7 +1,7 @@
 FILE: genericFunctions.kt
     public? abstract interface Any() {
     }
-    <reified T : Any> public? final? inline function safeAsR/Any/.(): R/T/ {
+    <reified T : Any> public? final? inline function safeAs R/Any/.(): R/T/ {
         STUB
     }
     public? abstract class Summator() {

compiler/tests/org/jetbrains/kotlin/fir/FirResolveTestCaseGenerated.java

@@ -39,6 +39,12 @@ public class FirResolveTestCaseGenerated extends AbstractFirResolveTestCase {
         runTest("compiler/testData/fir/resolve/F.kt");
     }
 
+    @TestMetadata("functionTypes.kt")
+    public void testFunctionTypes() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/fir/resolve/functionTypes.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("genericFunctions.kt")
     public void testGenericFunctions() throws Exception {
         runTest("compiler/testData/fir/resolve/genericFunctions.kt");