Adds property merging strategies

1 files changed, 13 insertions, 2 deletions

diff --git a/core/src/main/kotlin/model/properties/properties.kt b/core/src/main/kotlin/model/properties/properties.kt
index 5ff1305a..4ca44926 100644
--- a/core/src/main/kotlin/model/properties/properties.kt
+++ b/core/src/main/kotlin/model/properties/properties.kt
@@ -1,10 +1,21 @@
 package org.jetbrains.dokka.model.properties
 
 interface Property<in C : Any> {
-    interface Key<in C: Any, T: Any>
+    interface Key<in C: Any, T: Any> {
+        fun mergeStrategyFor(left: T, right: T): MergeStrategy<C> = MergeStrategy.Fail {
+            throw NotImplementedError("Property merging for $this is not implemented")
+        }
+    }
     val key: Key<C, *>
 }
 
 interface CalculatedProperty<in C: Any, T: Any>: Property.Key<C, T> {
     fun calculate(subject: C): T
-}
\ No newline at end of file
+}
+
+sealed class MergeStrategy<in C> {
+    class Replace<in C : Any>(val newProperty: Property<C>): MergeStrategy<C>()
+    object Remove: MergeStrategy<Any>()
+    class Full<C: Any>(val merger: (preMerged: C, left: C, right: C) -> C): MergeStrategy<C>()
+    class Fail(val error: () -> Nothing): MergeStrategy<Any>()
+}