Added map and array types to avro type hierarchy

centurion-avro/src/main/kotlin/com/sksamuel/centurion/avro/encoders/Encoder.kt

@@ -40,8 +40,8 @@ fun interface Encoder<T> {
             Int::class -> IntEncoder
             Long::class -> LongEncoder
             BigDecimal::class -> BigDecimalStringEncoder
-            Set::class -> GenericArraySetEncoder(encoderFor(type.arguments.first().type!!))
-            List::class -> GenericArrayListEncoder(encoderFor(type.arguments.first().type!!))
+            Set::class -> SetEncoder(encoderFor(type.arguments.first().type!!))
+            List::class -> ListEncoder(encoderFor(type.arguments.first().type!!))
             Map::class -> MapEncoder(encoderFor(type.arguments[1].type!!))
             is KClass<*> -> if (classifier.java.isEnum) EnumEncoder<Enum<*>>() else error("Unsupported type $type")
             else -> error("Unsupported type $type")

centurion-avro/src/main/kotlin/com/sksamuel/centurion/avro/encoders/collections.kt

@@ -7,7 +7,7 @@ import org.apache.avro.generic.GenericData
 /**
  * An [Encoder] for Arrays of [T] that encodes into an Avro [GenericArray].
  */
-class GenericArrayArrayEncoder<T>(private val encoder: Encoder<T>) : Encoder<Array<T>> {
+class ArrayEncoder<T>(private val encoder: Encoder<T>) : Encoder<Array<T>> {
    override fun encode(schema: Schema, value: Array<T>): Any {
       require(schema.type == Schema.Type.ARRAY)
       val elements = value.map { encoder.encode(schema.elementType, it) }
@@ -18,7 +18,7 @@ class GenericArrayArrayEncoder<T>(private val encoder: Encoder<T>) : Encoder<Arr
 /**
  * An [Encoder] for Lists of [T] that encodes into an Avro [GenericArray].
  */
-class GenericArrayListEncoder<T>(private val encoder: Encoder<T>) : Encoder<List<T>> {
+class ListEncoder<T>(private val encoder: Encoder<T>) : Encoder<List<T>> {
    override fun encode(schema: Schema, value: List<T>): Any {
       require(schema.type == Schema.Type.ARRAY)
       val elements = value.map { encoder.encode(schema.elementType, it) }
@@ -29,7 +29,7 @@ class GenericArrayListEncoder<T>(private val encoder: Encoder<T>) : Encoder<List
 /**
  * An [Encoder] for Sets of [T] that encodes into an Avro [GenericArray].
  */
-class GenericArraySetEncoder<T>(private val encoder: Encoder<T>) : Encoder<Set<T>> {
+class SetEncoder<T>(private val encoder: Encoder<T>) : Encoder<Set<T>> {
    override fun encode(schema: Schema, value: Set<T>): GenericArray<Any> {
       require(schema.type == Schema.Type.ARRAY)
       val elements = value.map { encoder.encode(schema.elementType, it) }

centurion-avro/src/main/kotlin/com/sksamuel/centurion/avro/generation/DataClassGenerator.kt

@@ -14,17 +14,22 @@ class DataClassGenerator {
    }
 
    private fun member(field: Schema.Field): Member {
-      val type = when (field.schema().type) {
-         Schema.Type.RECORD -> Type.RecordType(field.schema().namespace, field.schema().name)
+      return Member(field.name(), schema(field.schema()))
+   }
+
+   private fun schema(schema: Schema): Type {
+      return when (val type = schema.type) {
+         Schema.Type.RECORD -> Type.RecordType(schema.namespace, schema.name)
          Schema.Type.STRING -> Type.StringType
          Schema.Type.INT -> Type.IntType
          Schema.Type.LONG -> Type.LongType
          Schema.Type.FLOAT -> Type.FloatType
          Schema.Type.DOUBLE -> Type.DoubleType
          Schema.Type.BOOLEAN -> Type.BooleanType
+         Schema.Type.ARRAY -> Type.ArrayType(schema(schema.elementType))
+         Schema.Type.MAP -> Type.ArrayType(schema(schema.valueType))
          else -> error("Invalid code path")
       }
-      return Member(field.name(), type)
    }
 }
 
@@ -42,6 +47,9 @@ sealed interface Type {
    object FloatType : Type
    object DoubleType : Type
 
+   data class ArrayType(val elementType: Type) : Type
+   data class MapType(val valueType: Type) : Type
+
    // a nullable type wraps any other type, denoting that it is permitted to be null
    // this is analogous to Avro's union type, with two elements - null and another
    data class Nullable(val element: Type) : Type

centurion-avro/src/main/kotlin/com/sksamuel/centurion/avro/generation/DataClassWriter.kt

@@ -26,6 +26,8 @@ object DataClassWriter {
          is Type.RecordType -> type.packageName + "." + type.className
          Type.StringType -> "String"
          is Type.Nullable -> typeToString(type.element) + "?"
+         is Type.ArrayType -> "List<${typeToString(type.elementType)}>"
+         is Type.MapType -> "Map<String, ${typeToString(type.valueType)}>"
       }
    }
 }

centurion-avro/src/main/kotlin/com/sksamuel/centurion/avro/generation/RecordDecoderGenerator.kt

@@ -43,6 +43,8 @@ class RecordDecoderGenerator {
          is Type.Nullable -> TODO()
          is Type.RecordType -> TODO()
          Type.StringType -> "StringDecoder.decode($getSchema, $getValue)"
+         is Type.ArrayType -> "ListDecoder.decode($getSchema, $getValue)"
+         is Type.MapType -> "MapDecoder.decode($getSchema, $getValue)"
       }
    }
 }

centurion-avro/src/main/kotlin/com/sksamuel/centurion/avro/generation/RecordEncoderGenerator.kt

@@ -37,6 +37,8 @@ class RecordEncoderGenerator {
          is Type.Nullable -> TODO()
          is Type.RecordType -> TODO()
          Type.StringType -> "StringEncoder.encode($getSchema, value.${member.name})"
+         is Type.ArrayType -> "ListEncoder.encode($getSchema, value.${member.name})"
+         is Type.MapType -> "MapEncoder.encode($getSchema, value.${member.name})"
       }
    }
 }