Initial commit

youtube-music/src/main/kotlin/it/vfsfitvnm/youtubemusic/Outcome.kt

@@ -0,0 +1,68 @@
+package it.vfsfitvnm.youtubemusic
+
+
+sealed class Outcome<out T> {
+    val valueOrNull: T?
+        get() = when (this) {
+            is Success -> value
+            is Recovered -> value
+            else -> null
+        }
+
+    fun recoverWith(value: @UnsafeVariance T): Outcome<T> {
+        return when (this) {
+            is Error -> Recovered(value, this)
+            else -> this
+        }
+    }
+
+    inline fun <R> map(block: (T) -> R): Outcome<R> {
+        return when (this) {
+            is Success -> Success(block(value))
+            is Recovered -> Success(block(value))
+            is Initial -> this
+            is Loading -> this
+            is Error -> this
+        }
+    }
+
+    inline fun <R> flatMap(block: (T) -> Outcome<R>): Outcome<R> {
+        return when (this) {
+            is Success -> block(value)
+            is Recovered -> block(value)
+            is Initial -> this
+            is Loading -> this
+            is Error -> this
+        }
+    }
+
+    object Initial : Outcome<Nothing>()
+
+    object Loading : Outcome<Nothing>()
+
+    sealed class Error : Outcome<Nothing>() {
+        object Network : Error()
+        class Unhandled(val throwable: Throwable) : Error()
+    }
+
+    class Recovered<T>(val value: T, val error: Error) : Outcome<T>()
+    
+    class Success<T>(val value: T) : Outcome<T>()
+}
+
+fun <T> Outcome<T>?.toNotNull(): Outcome<T?> {
+    return when (this) {
+        null -> Outcome.Success(null)
+        else -> this
+    }
+}
+
+fun <T> Outcome<T?>.toNullable(): Outcome<T>? {
+    return valueOrNull?.let {
+        Outcome.Success(it)
+    }
+}
+
+val Outcome<*>.isEvaluable: Boolean
+    get() = this !is Outcome.Success && this !is Outcome.Loading
+