[FIR] Improved lambda completion: initial implementation

Repeat the logic of KotlinConstraintSystemCompleter in ConstraintSystemCompleter.
Implement additional context operations required for updated lambda completion algorithm.

core/compiler.common/src/org/jetbrains/kotlin/builtins/StandardNames.kt

@@ -208,14 +208,20 @@ object StandardNames {
         return "Function$parameterCount"
     }
 
+    @JvmStatic
+    fun getFunctionClassId(parameterCount: Int): ClassId {
+        return ClassId(BUILT_INS_PACKAGE_FQ_NAME, Name.identifier(getFunctionName(parameterCount)))
+    }
+
     @JvmStatic
     fun getKFunctionFqName(parameterCount: Int): FqNameUnsafe {
         return reflect(FunctionClassKind.KFunction.classNamePrefix + parameterCount)
     }
 
     @JvmStatic
-    fun getFunctionClassId(parameterCount: Int): ClassId {
-        return ClassId(BUILT_INS_PACKAGE_FQ_NAME, Name.identifier(getFunctionName(parameterCount)))
+    fun getKFunctionClassId(parameterCount: Int): ClassId {
+        val fqName = getKFunctionFqName(parameterCount)
+        return ClassId(fqName.parent().toSafe(), fqName.shortName())
     }
 
     @JvmStatic
@@ -228,6 +234,17 @@ object StandardNames {
         return ClassId(COROUTINES_PACKAGE_FQ_NAME_RELEASE, Name.identifier(getSuspendFunctionName(parameterCount)))
     }
 
+    @JvmStatic
+    fun getKSuspendFunctionName(parameterCount: Int): FqNameUnsafe {
+        return reflect(FunctionClassKind.KSuspendFunction.classNamePrefix + parameterCount)
+    }
+
+    @JvmStatic
+    fun getKSuspendFunctionClassId(parameterCount: Int): ClassId {
+        val fqName = getKSuspendFunctionName(parameterCount)
+        return ClassId(fqName.parent().toSafe(), fqName.shortName())
+    }
+
     @JvmStatic
     fun isPrimitiveArray(arrayFqName: FqNameUnsafe): Boolean {
         return FqNames.arrayClassFqNameToPrimitiveType.get(arrayFqName) != null

core/compiler.common/src/org/jetbrains/kotlin/types/model/TypeSystemContext.kt

@@ -193,6 +193,20 @@ interface TypeSystemInferenceExtensionContext : TypeSystemContext, TypeSystemBui
     fun TypeVariableTypeConstructorMarker.isContainedInInvariantOrContravariantPositions(): Boolean
 
     fun KotlinTypeMarker.isSignedOrUnsignedNumberType(): Boolean
+
+    fun KotlinTypeMarker.isFunctionOrKFunctionWithAnySuspendability(): Boolean
+
+    fun KotlinTypeMarker.isSuspendFunctionTypeOrSubtype(): Boolean
+
+    fun KotlinTypeMarker.isExtensionFunctionType(): Boolean
+
+    fun KotlinTypeMarker.extractArgumentsForFunctionalTypeOrSubtype(): List<KotlinTypeMarker>
+
+    fun KotlinTypeMarker.getFunctionalTypeFromSupertypes(): KotlinTypeMarker
+
+    fun getFunctionTypeConstructor(parametersNumber: Int, isSuspend: Boolean): TypeConstructorMarker
+
+    fun getKFunctionTypeConstructor(parametersNumber: Int, isSuspend: Boolean): TypeConstructorMarker
 }
 
 

core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt

@@ -5,10 +5,8 @@
 
 package org.jetbrains.kotlin.types.checker
 
-import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.builtins.PrimitiveType
+import org.jetbrains.kotlin.builtins.*
 import org.jetbrains.kotlin.builtins.StandardNames.FqNames
-import org.jetbrains.kotlin.builtins.isBuiltinFunctionalTypeOrSubtype
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
@@ -674,6 +672,39 @@ interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSy
 
         } ?: error("Expected intersection type, found $firstCandidate")
     }
+
+    override fun KotlinTypeMarker.isFunctionOrKFunctionWithAnySuspendability(): Boolean {
+        require(this is KotlinType, this::errorMessage)
+        return this.isFunctionOrKFunctionTypeWithAnySuspendability
+    }
+
+    override fun KotlinTypeMarker.isSuspendFunctionTypeOrSubtype(): Boolean {
+        require(this is KotlinType, this::errorMessage)
+        return this.isSuspendFunctionTypeOrSubtype
+    }
+
+    override fun KotlinTypeMarker.isExtensionFunctionType(): Boolean {
+        require(this is KotlinType, this::errorMessage)
+        return this.isExtensionFunctionType
+    }
+
+    override fun KotlinTypeMarker.extractArgumentsForFunctionalTypeOrSubtype(): List<KotlinTypeMarker> {
+        require(this is KotlinType, this::errorMessage)
+        return this.getPureArgumentsForFunctionalTypeOrSubtype()
+    }
+
+    override fun KotlinTypeMarker.getFunctionalTypeFromSupertypes(): KotlinTypeMarker {
+        require(this is KotlinType)
+        return this.extractFunctionalTypeFromSupertypes()
+    }
+
+    override fun getFunctionTypeConstructor(parametersNumber: Int, isSuspend: Boolean): TypeConstructorMarker {
+        return getFunctionDescriptor(builtIns, parametersNumber, isSuspend).typeConstructor
+    }
+
+    override fun getKFunctionTypeConstructor(parametersNumber: Int, isSuspend: Boolean): TypeConstructorMarker {
+        return getKFunctionDescriptor(builtIns, parametersNumber, isSuspend).typeConstructor
+    }
 }
 
 fun TypeVariance.convertVariance(): Variance {