Expand Gotlin language and tooling

examples/mapping.gt

@@ -0,0 +1,40 @@
+package main
+
+data class AddressEntity(var city: String)
+data class AddressResponse(var city: String)
+
+enum EntityState {
+    Active
+    Failed(String)
+}
+
+enum ResponseState {
+    Active
+    Failed(String)
+    Pending
+}
+
+data class AccountEntity(
+    var id: String,
+    var address: *AddressEntity,
+    var labels: List<String>,
+    var state: EntityState
+)
+
+data class AccountResponse(
+    var address: *AddressResponse,
+    var id: String,
+    var labels: List<String>,
+    var state: ResponseState
+)
+
+fun main() {
+    val entity = AccountEntity("account-1", AddressEntity("Berlin"), listOf("active"), EntityState::Active)
+    val response = entity.mapTo<AccountResponse>()
+    println(response.address.city)
+    match (response.state) {
+        ResponseState::Active -> { println("active") }
+        ResponseState::Failed(reason) -> { println(reason) }
+        ResponseState::Pending -> { println("pending") }
+    }
+}