[MatrixSDK] finish mapping timeline and makes it compile

libraries/core/src/main/kotlin/io/element/android/libraries/core/extensions/Result.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.libraries.core.extensions
+
+/**
+ * Can be used to transform some Throwable into some other
+ */
+inline fun <R, T : R> Result<T>.mapFailure(transform: (exception: Throwable) -> Throwable): Result<R> {
+    return when (val exception = exceptionOrNull()) {
+        null -> this
+        else -> Result.failure(transform(exception))
+    }
+}