src/main/java/net/pterodactylus/rhynodge/queries/FallbackQuery.kt

   1 package net.pterodactylus.rhynodge.queries
   2
   3 import net.pterodactylus.rhynodge.Query
   4 import net.pterodactylus.rhynodge.State
   5 import net.pterodactylus.rhynodge.states.FailedState
   6
   7 /**
   8  * [Query] that can run a number of other [Query]s, returning the first successful [State] that is encountered.
   9  *
  10  * @author [David ‘Bombe’ Roden](mailto:bombe@pterodactylus.net)
  11  */
  12 class FallbackQuery(private vararg val queries: Query) : Query {
  13
  14         init {
  15                 if (queries.isEmpty()) {
  16                         throw IllegalArgumentException("queries must not be empty")
  17                 }
  18         }
  19
  20         override fun state(): State {
  21                 var lastFailedState: State = FailedState()
  22                 queries.asSequence().map(Query::state).forEach { lastFailedState = it; if (it.success()) return it }
  23                 return lastFailedState
  24         }
  25
  26 }