Added descriptors to custom serializers

dataforge-io/src/commonMain/kotlin/hep/dataforge/io/serialization/MetaSerializer.kt

@@ -17,9 +17,9 @@ object ValueSerializer : KSerializer<Value> {
     private val listSerializer by lazy { ArrayListSerializer(ValueSerializer) }
 
     override val descriptor: SerialDescriptor = descriptor("Value") {
-        element("isList")
-        element("valueType")
-        element("value")
+        boolean("isList")
+        enum<ValueType>("valueType")
+        element("value", PolymorphicClassDescriptor)
     }
 
     private fun Decoder.decodeValue(): Value {
@@ -68,10 +68,11 @@ object ValueSerializer : KSerializer<Value> {
 @Serializer(MetaItem::class)
 object MetaItemSerializer : KSerializer<MetaItem<*>> {
     override val descriptor: SerialDescriptor = descriptor("MetaItem") {
-        element("isNode")
-        element("value")
+        boolean("isNode")
+        element("value", PolymorphicClassDescriptor)
     }
 
+
     override fun deserialize(decoder: Decoder): MetaItem<*> {
         val isNode = decoder.decodeBoolean()
         return if (isNode) {

dataforge-io/src/commonMain/kotlin/hep/dataforge/io/serialization/serializationUtils.kt

@@ -4,19 +4,64 @@ import kotlinx.serialization.CompositeDecoder
 import kotlinx.serialization.Decoder
 import kotlinx.serialization.KSerializer
 import kotlinx.serialization.SerialDescriptor
-import kotlinx.serialization.internal.SerialClassDescImpl
+import kotlinx.serialization.internal.*
 
+/**
+ * A convenience builder for serial descriptors
+ */
 inline class SerialDescriptorBuilder(private val impl: SerialClassDescImpl) {
-    fun element(name: String, isOptional: Boolean = false) = impl.addElement(name, isOptional)
+    fun element(
+        name: String,
+        descriptor: SerialDescriptor,
+        isOptional: Boolean = false,
+        vararg annotations: Annotation
+    ) {
+        impl.addElement(name, isOptional)
+        impl.pushDescriptor(descriptor)
+        annotations.forEach {
+            impl.pushAnnotation(it)
+        }
+    }
 
-    fun annotation(a: Annotation) = impl.pushAnnotation(a)
+    fun element(
+        name: String,
+        isOptional: Boolean = false,
+        vararg annotations: Annotation,
+        block: SerialDescriptorBuilder.() -> Unit
+    ) {
+        impl.addElement(name, isOptional)
+        impl.pushDescriptor(SerialDescriptorBuilder(SerialClassDescImpl(name)).apply(block).build())
+        annotations.forEach {
+            impl.pushAnnotation(it)
+        }
+    }
+
+    fun boolean(name: String, isOptional: Boolean = false, vararg annotations: Annotation) =
+        element(name, BooleanDescriptor, isOptional, *annotations)
+
+    fun string(name: String, isOptional: Boolean = false, vararg annotations: Annotation) =
+        element(name, StringDescriptor, isOptional, *annotations)
+
+    fun int(name: String, isOptional: Boolean = false, vararg annotations: Annotation) =
+        element(name, IntDescriptor, isOptional, *annotations)
+
+    fun double(name: String, isOptional: Boolean = false, vararg annotations: Annotation) =
+        element(name, DoubleDescriptor, isOptional, *annotations)
+
+    fun float(name: String, isOptional: Boolean = false, vararg annotations: Annotation) =
+        element(name, FloatDescriptor, isOptional, *annotations)
+
+    fun long(name: String, isOptional: Boolean = false, vararg annotations: Annotation) =
+        element(name, LongDescriptor, isOptional, *annotations)
+
+    fun doubleArray(name: String, isOptional: Boolean = false, vararg annotations: Annotation) =
+        element(name, DoubleArraySerializer.descriptor, isOptional, *annotations)
+
+    inline fun <reified E: Enum<E>> enum(name: String, isOptional: Boolean = false, vararg annotations: Annotation) =
+        element(name, EnumSerializer(E::class).descriptor, isOptional, *annotations)
 
     fun classAnnotation(a: Annotation) = impl.pushClassAnnotation(a)
 
-    fun descriptor(name: String, block: SerialDescriptorBuilder.() -> Unit) = impl.pushDescriptor(
-        SerialDescriptorBuilder(SerialClassDescImpl(name)).apply(block).build()
-    )
-
     fun build(): SerialDescriptor = impl
 }
 

dataforge-io/src/commonTest/kotlin/hep/dataforge/io/MetaSerializerTest.kt

@@ -51,4 +51,9 @@ class MetaSerializerTest {
         val restored = Json.plain.parse(NameSerializer, string)
         assertEquals(restored, name)
     }
+
+    @Test
+    fun testMetaItemDescriptor(){
+        val descriptor = MetaItemSerializer.descriptor.getElementDescriptor(0)
+    }
 }