KT-12810 IDL: support special modifiers(e.g. getter and setter)

js/js.libraries/src/generated/org.khronos.webgl.kt

@@ -595,8 +595,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Byte = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Byte): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Byte = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Byte): Unit = noImpl
     fun set(array: Int8Array, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Byte>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Int8Array = noImpl
@@ -619,8 +622,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Byte = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Byte): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Byte = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Byte): Unit = noImpl
     fun set(array: Uint8Array, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Byte>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Uint8Array = noImpl
@@ -643,8 +649,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Byte = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Byte): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Byte = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Byte): Unit = noImpl
     fun set(array: Uint8ClampedArray, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Byte>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Uint8ClampedArray = noImpl
@@ -667,8 +676,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Short = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Short): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Short = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Short): Unit = noImpl
     fun set(array: Int16Array, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Short>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Int16Array = noImpl
@@ -691,8 +703,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Short = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Short): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Short = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Short): Unit = noImpl
     fun set(array: Uint16Array, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Short>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Uint16Array = noImpl
@@ -715,8 +730,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Int = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Int): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Int = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Int): Unit = noImpl
     fun set(array: Int32Array, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Int>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Int32Array = noImpl
@@ -739,8 +757,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Int = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Int): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Int = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Int): Unit = noImpl
     fun set(array: Uint32Array, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Int>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Uint32Array = noImpl
@@ -763,8 +784,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Float = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Float): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Float = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Float): Unit = noImpl
     fun set(array: Float32Array, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Float>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Float32Array = noImpl
@@ -787,8 +811,11 @@ public inline fun WebGLContextEventInit(statusMessage: String, bubbles: Boolean
         get() = noImpl
     open val byteLength: Int
         get() = noImpl
-    fun get(index: Int): Double = noImpl
+    @Suppress("NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE")
-    fun set(index: Int, value: Double): Unit = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Double = noImpl
+    @nativeSetter
+    operator fun set(index: Int, value: Double): Unit = noImpl
     fun set(array: Float64Array, offset: Int = noImpl): Unit = noImpl
     fun set(array: Array<Double>, offset: Int = noImpl): Unit = noImpl
     fun subarray(start: Int, end: Int): Float64Array = noImpl

js/js.libraries/src/generated/org.w3c.dom.css.kt

@@ -707,7 +707,8 @@ import org.w3c.xhr.*
         get() = noImpl
         set(value) = noImpl
     fun item(index: Int): String = noImpl
-    operator @nativeGetter fun get(index: Int): String? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): String? = noImpl
     fun getPropertyValue(property: String): String = noImpl
     fun getPropertyPriority(property: String): String = noImpl
     fun setProperty(property: String, value: String, priority: String = ""): Unit = noImpl
@@ -723,7 +724,8 @@ import org.w3c.xhr.*
     val length: Int
         get() = noImpl
     fun item(index: Int): String? = noImpl
-    operator @nativeGetter fun get(index: Int): String? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): String? = noImpl
     fun appendMedium(medium: String): Unit = noImpl
     fun deleteMedium(medium: String): Unit = noImpl
 }
@@ -759,14 +761,16 @@ import org.w3c.xhr.*
     val length: Int
         get() = noImpl
     fun item(index: Int): StyleSheet? = noImpl
-    operator @nativeGetter fun get(index: Int): StyleSheet? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): StyleSheet? = noImpl
 }
 
 @native public interface CSSRuleList {
     val length: Int
         get() = noImpl
     fun item(index: Int): CSSRule? = noImpl
-    operator @nativeGetter fun get(index: Int): CSSRule? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): CSSRule? = noImpl
 }
 
 @native public interface CSSRule {

js/js.libraries/src/generated/org.w3c.dom.kt

@@ -334,7 +334,8 @@ import org.w3c.xhr.*
     open val childElementCount: Int
         get() = noImpl
     fun exitFullscreen(): Unit = noImpl
-    operator @nativeGetter fun get(name: String): dynamic = noImpl
+    @nativeGetter
+    operator fun get(name: String): dynamic = noImpl
     fun getElementsByName(elementName: String): NodeList = noImpl
     fun getItems(typeNames: String = ""): NodeList = noImpl
     fun open(type: String = "text/html", replace: String = ""): Document = noImpl
@@ -704,8 +705,10 @@ import org.w3c.xhr.*
     fun focus(): Unit = noImpl
     fun blur(): Unit = noImpl
     fun open(url: String = "about:blank", target: String = "_blank", features: String = "", replace: Boolean = false): Window = noImpl
-    operator @nativeGetter fun get(index: Int): Window? = noImpl
+    @nativeGetter
-    operator @nativeGetter fun get(name: String): dynamic = noImpl
+    operator fun get(index: Int): Window? = noImpl
+    @nativeGetter
+    operator fun get(name: String): dynamic = noImpl
     fun alert(): Unit = noImpl
     fun alert(message: String): Unit = noImpl
     fun confirm(message: String = ""): Boolean = noImpl
@@ -854,12 +857,14 @@ import org.w3c.xhr.*
 @native public interface HTMLAllCollection : HTMLCollection {
     fun item(name: String): UnionElementOrHTMLCollection? = noImpl
 //    override fun namedItem(name: String): UnionElementOrHTMLCollection? = noImpl
-//    operator @nativeGetter override fun get(name: String): UnionElementOrHTMLCollection? = noImpl
+//    @nativeGetter
+//    operator override fun get(name: String): UnionElementOrHTMLCollection? = noImpl
 }
 
 @native public interface HTMLFormControlsCollection : HTMLCollection {
 //    override fun namedItem(name: String): UnionElementOrRadioNodeList? = noImpl
-//    operator @nativeGetter override fun get(name: String): UnionElementOrRadioNodeList? = noImpl
+//    @nativeGetter
+//    operator override fun get(name: String): UnionElementOrRadioNodeList? = noImpl
 }
 
 @native public interface RadioNodeList : NodeList, UnionElementOrRadioNodeList {
@@ -875,7 +880,8 @@ import org.w3c.xhr.*
     var selectedIndex: Int
         get() = noImpl
         set(value) = noImpl
-    operator @nativeSetter fun set(index: Int, option: HTMLOptionElement?): Unit = noImpl
+    @nativeSetter
+    operator fun set(index: Int, option: HTMLOptionElement?): Unit = noImpl
     fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement, before: dynamic = null): Unit = noImpl
     fun remove(index: Int): Unit = noImpl
 }
@@ -884,7 +890,8 @@ import org.w3c.xhr.*
     val names: Array<String>
         get() = noImpl
 //    override fun namedItem(name: String): PropertyNodeList? = noImpl
-//    operator @nativeGetter override fun get(name: String): PropertyNodeList? = noImpl
+//    @nativeGetter
+//    operator override fun get(name: String): PropertyNodeList? = noImpl
 }
 
 @native public interface PropertyNodeList : NodeList {
@@ -892,13 +899,17 @@ import org.w3c.xhr.*
 }
 
 @native public interface DOMStringMap {
-    operator @nativeGetter fun get(name: String): String? = noImpl
+    @nativeGetter
-    operator @nativeSetter fun set(name: String, value: String): Unit = noImpl
+    operator fun get(name: String): String? = noImpl
+    @nativeSetter
+    operator fun set(name: String, value: String): Unit = noImpl
 }
 
 @native public interface DOMElementMap {
-    operator @nativeGetter fun get(name: String): Element? = noImpl
+    @nativeGetter
-    operator @nativeSetter fun set(name: String, value: Element): Unit = noImpl
+    operator fun get(name: String): Element? = noImpl
+    @nativeSetter
+    operator fun set(name: String, value: Element): Unit = noImpl
 }
 
 @native public open class XMLDocument : Document() {
@@ -1869,7 +1880,8 @@ import org.w3c.xhr.*
     var onremovetrack: ((Event) -> dynamic)?
         get() = noImpl
         set(value) = noImpl
-    operator @nativeGetter fun get(index: Int): AudioTrack? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): AudioTrack? = noImpl
     fun getTrackById(id: String): AudioTrack? = noImpl
 }
 
@@ -1901,7 +1913,8 @@ import org.w3c.xhr.*
     var onremovetrack: ((Event) -> dynamic)?
         get() = noImpl
         set(value) = noImpl
-    operator @nativeGetter fun get(index: Int): VideoTrack? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): VideoTrack? = noImpl
     fun getTrackById(id: String): VideoTrack? = noImpl
 }
 
@@ -2008,7 +2021,8 @@ import org.w3c.xhr.*
     var onremovetrack: ((Event) -> dynamic)?
         get() = noImpl
         set(value) = noImpl
-    operator @nativeGetter fun get(index: Int): TextTrack? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): TextTrack? = noImpl
     fun getTrackById(id: String): TextTrack? = noImpl
 }
 
@@ -2040,7 +2054,8 @@ import org.w3c.xhr.*
 @native public interface TextTrackCueList {
     val length: Int
         get() = noImpl
-    operator @nativeGetter fun get(index: Int): TextTrackCue? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): TextTrackCue? = noImpl
     fun getCueById(id: String): TextTrackCue? = noImpl
 }
 
@@ -2393,8 +2408,10 @@ public inline fun TrackEventInit(track: UnionAudioTrackOrTextTrackOrVideoTrack?,
         get() = noImpl
     val length: Int
         get() = noImpl
-    operator @nativeGetter fun get(index: Int): Element? = noImpl
+    @nativeGetter
-    operator @nativeGetter fun get(name: String): UnionElementOrRadioNodeList? = noImpl
+    operator fun get(index: Int): Element? = noImpl
+    @nativeGetter
+    operator fun get(name: String): UnionElementOrRadioNodeList? = noImpl
     fun submit(): Unit = noImpl
     fun reset(): Unit = noImpl
     fun checkValidity(): Boolean = noImpl
@@ -2661,11 +2678,13 @@ public inline fun TrackEventInit(track: UnionAudioTrackOrTextTrackOrVideoTrack?,
     val labels: NodeList
         get() = noImpl
     fun item(index: Int): Element? = noImpl
-    operator @nativeGetter fun get(index: Int): Element? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Element? = noImpl
     fun namedItem(name: String): HTMLOptionElement? = noImpl
     fun add(element: UnionHTMLOptGroupElementOrHTMLOptionElement, before: dynamic = null): Unit = noImpl
     fun remove(index: Int): Unit = noImpl
-    operator @nativeSetter fun set(index: Int, option: HTMLOptionElement?): Unit = noImpl
+    @nativeSetter
+    operator fun set(index: Int, option: HTMLOptionElement?): Unit = noImpl
     fun checkValidity(): Boolean = noImpl
     fun reportValidity(): Boolean = noImpl
     fun setCustomValidity(error: String): Unit = noImpl
@@ -3389,7 +3408,8 @@ public inline fun HitRegionOptions(path: Path2D? = null, fillRule: String = "non
 @native public interface DataTransferItemList {
     val length: Int
         get() = noImpl
-    operator @nativeGetter fun get(index: Int): DataTransferItem? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): DataTransferItem? = noImpl
     fun add(data: String, type: String): DataTransferItem? = noImpl
     fun add(data: File): DataTransferItem? = noImpl
     fun remove(index: Int): Unit = noImpl
@@ -3704,18 +3724,22 @@ public inline fun ErrorEventInit(message: String, filename: String, lineno: Int,
         get() = noImpl
     fun refresh(reload: Boolean = false): Unit = noImpl
     fun item(index: Int): Plugin? = noImpl
-    operator @nativeGetter fun get(index: Int): Plugin? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Plugin? = noImpl
     fun namedItem(name: String): Plugin? = noImpl
-    operator @nativeGetter fun get(name: String): Plugin? = noImpl
+    @nativeGetter
+    operator fun get(name: String): Plugin? = noImpl
 }
 
 @native public interface MimeTypeArray {
     val length: Int
         get() = noImpl
     fun item(index: Int): MimeType? = noImpl
-    operator @nativeGetter fun get(index: Int): MimeType? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): MimeType? = noImpl
     fun namedItem(name: String): MimeType? = noImpl
-    operator @nativeGetter fun get(name: String): MimeType? = noImpl
+    @nativeGetter
+    operator fun get(name: String): MimeType? = noImpl
 }
 
 @native public interface Plugin {
@@ -3728,9 +3752,11 @@ public inline fun ErrorEventInit(message: String, filename: String, lineno: Int,
     val length: Int
         get() = noImpl
     fun item(index: Int): MimeType? = noImpl
-    operator @nativeGetter fun get(index: Int): MimeType? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): MimeType? = noImpl
     fun namedItem(name: String): MimeType? = noImpl
-    operator @nativeGetter fun get(name: String): MimeType? = noImpl
+    @nativeGetter
+    operator fun get(name: String): MimeType? = noImpl
 }
 
 @native public interface MimeType {
@@ -4057,9 +4083,11 @@ public inline fun CloseEventInit(wasClean: Boolean, code: Short, reason: String,
         get() = noImpl
     fun key(index: Int): String? = noImpl
     fun getItem(key: String): String? = noImpl
-    operator @nativeGetter fun get(key: String): String? = noImpl
+    @nativeGetter
+    operator fun get(key: String): String? = noImpl
     fun setItem(key: String, value: String): Unit = noImpl
-    operator @nativeSetter fun set(key: String, value: String): Unit = noImpl
+    @nativeSetter
+    operator fun set(key: String, value: String): Unit = noImpl
     fun removeItem(key: String): Unit = noImpl
     fun clear(): Unit = noImpl
 }
@@ -4380,16 +4408,19 @@ public inline fun CustomEventInit(detail: Any? = null, bubbles: Boolean = false,
     val length: Int
         get() = noImpl
     fun item(index: Int): Node? = noImpl
-    operator @nativeGetter fun get(index: Int): Node? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Node? = noImpl
 }
 
 @native public interface HTMLCollection : UnionElementOrHTMLCollection {
     val length: Int
         get() = noImpl
     fun item(index: Int): Element? = noImpl
-    operator @nativeGetter fun get(index: Int): Element? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Element? = noImpl
     fun namedItem(name: String): Element? = noImpl
-    operator @nativeGetter fun get(name: String): Element? = noImpl
+    @nativeGetter
+    operator fun get(name: String): Element? = noImpl
 }
 
 @native public open class MutationObserver(callback: (Array<MutationRecord>, MutationObserver) -> Unit) {
@@ -4551,9 +4582,11 @@ public inline fun MutationObserverInit(childList: Boolean = false, attributes: B
     val length: Int
         get() = noImpl
     fun item(index: Int): Attr? = noImpl
-    operator @nativeGetter fun get(index: Int): Attr? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): Attr? = noImpl
     fun getNamedItem(name: String): Attr? = noImpl
-    operator @nativeGetter fun get(name: String): Attr? = noImpl
+    @nativeGetter
+    operator fun get(name: String): Attr? = noImpl
     fun getNamedItemNS(namespace: String?, localName: String): Attr? = noImpl
     fun setNamedItem(attr: Attr): Attr? = noImpl
     fun setNamedItemNS(attr: Attr): Attr? = noImpl
@@ -4733,7 +4766,8 @@ public inline fun MutationObserverInit(childList: Boolean = false, attributes: B
     val length: Int
         get() = noImpl
     fun item(index: Int): String? = noImpl
-    operator @nativeGetter fun get(index: Int): String? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): String? = noImpl
     fun contains(token: String): Boolean = noImpl
     fun add(vararg tokens: String): Unit = noImpl
     fun remove(vararg tokens: String): Unit = noImpl

js/js.libraries/src/generated/org.w3c.files.kt

@@ -71,7 +71,8 @@ public inline fun FilePropertyBag(type: String = "", lastModified: Int): FilePro
     val length: Int
         get() = noImpl
     fun item(index: Int): File? = noImpl
-    operator @nativeGetter fun get(index: Int): File? = noImpl
+    @nativeGetter
+    operator fun get(index: Int): File? = noImpl
 }
 
 @native public open class FileReader : EventTarget {

libraries/tools/idl2k/src/main/kotlin/gen.kt

@@ -12,7 +12,7 @@ fun generateFunction(repository: Repository, function: Operation, functionName:
         function.attributes.map { it.call }.toSet().let { attributes ->
             GenerateFunction(
                     name = functionName,
-                    returnType = mapType(repository, function.returnType).let { mapped -> if (nativeGetterOrSetter == NativeGetterOrSetter.GETTER) mapped.toNullable() else mapped },
+                    returnType = mapType(repository, function.returnType).let { mapped -> if (nativeGetterOrSetter == NativeGetterOrSetter.GETTER) mapped.toNullableIfNonPrimitive() else mapped },
                     arguments = function.parameters.map {
                         GenerateAttribute(
                                 name = it.name,
@@ -31,7 +31,12 @@ fun generateFunction(repository: Repository, function: Operation, functionName:
         }
 
 fun generateFunctions(repository: Repository, function: Operation): List<GenerateFunction> {
-    val realFunction = if (function.name == "") null else generateFunction(repository, function, function.name, NativeGetterOrSetter.NONE)
+    val realFunction = when {
+        function.name == "" -> null
+        function.getterOrSetter() == NativeGetterOrSetter.NONE -> generateFunction(repository, function, function.name, NativeGetterOrSetter.NONE)
+        function.name == "get" || function.name == "set" -> null
+        else -> generateFunction(repository, function, function.name, NativeGetterOrSetter.NONE)
+    }
     val getterOrSetterFunction = when (function.getterOrSetter()) {
         NativeGetterOrSetter.NONE -> null
         NativeGetterOrSetter.GETTER -> generateFunction(repository, function, "get")

libraries/tools/idl2k/src/main/kotlin/render.kt

@@ -63,14 +63,21 @@ private fun Appendable.renderArgumentsDeclaration(args: List<GenerateAttribute>,
             StringBuilder().apply { renderAttributeDeclaration(it, it.override, false, omitDefaults) }
         }
 
-private fun renderCall(call: GenerateFunctionCall) = "${call.name.replaceKeywords()}(${call.arguments.joinToString(", ") { it.replaceKeywords() }})"
+private fun renderCall(call: GenerateFunctionCall) = "${call.name.replaceKeywords()}(${call.arguments.joinToString(separator = ", ", transform = String::replaceKeywords)})"
 
 private fun Appendable.renderFunctionDeclaration(f: GenerateFunction, override: Boolean, commented: Boolean, level: Int = 1) {
     indent(commented, level)
 
+    if (f.nativeGetterOrSetter == NativeGetterOrSetter.GETTER
+            && !f.returnType.nullable
+            && f.returnType != DynamicType) {
+        appendln("@Suppress(\"NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE\")")
+        indent(commented, level)
+    }
+
     when (f.nativeGetterOrSetter) {
-        NativeGetterOrSetter.GETTER -> append("operator @nativeGetter ")
+        NativeGetterOrSetter.GETTER -> { appendln("@nativeGetter"); indent(commented, level); append("operator ") }
-        NativeGetterOrSetter.SETTER -> append("operator @nativeSetter ")
+        NativeGetterOrSetter.SETTER -> { appendln("@nativeSetter"); indent(commented, level); append("operator ") }
         NativeGetterOrSetter.NONE -> {}
     }
 
@@ -217,7 +224,9 @@ fun betterFunction(f1: GenerateFunction, f2: GenerateFunction): GenerateFunction
         f1.copy(
                 arguments = f1.arguments
                         .zip(f2.arguments)
-                        .map { it.first.copy(type = it.map { it.type }.betterType(), name = it.map { it.name }.betterName()) }
+                        .map { it.first.copy(type = it.map { it.type }.betterType(), name = it.map { it.name }.betterName()) },
+                nativeGetterOrSetter = listOf(f1.nativeGetterOrSetter, f2.nativeGetterOrSetter)
+                        .firstOrNull { it != NativeGetterOrSetter.NONE } ?: NativeGetterOrSetter.NONE
         )
 
 private fun <F, T> Pair<F, F>.map(block: (F) -> T) = block(first) to block(second)

libraries/tools/idl2k/src/main/kotlin/types.kt

@@ -74,3 +74,15 @@ private fun <T: Type> T.withNullabilityImpl(nullable: Boolean): T = if (this.nul
 fun <T: Type> T.withNullability(nullable: Boolean): T = withNullabilityImpl(this.nullable or nullable)
 fun <T: Type> T.toNullable(): T = withNullabilityImpl(true)
 fun <T: Type> T.dropNullable(): T = withNullabilityImpl(false)
+
+@Suppress("UNCHECKED_CAST")
+fun <T: Type> T.toNullableIfNonPrimitive(): T = when (this) {
+    is UnitType -> UnitType
+    is DynamicType -> DynamicType
+
+    is SimpleType -> when (this.type) {
+        "Int", "Short", "Byte", "Float", "Double", "Boolean", "Long" -> this
+        else -> this.toNullable()
+    }
+    else -> this.toNullable()
+} as T