/*
* Copyright 2018 Allan Wang
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
package com.pitchedapps.frost.utils
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.ExperimentalCoroutinesApi
import kotlinx.coroutines.channels.ReceiveChannel
import kotlinx.coroutines.channels.produce
import kotlinx.coroutines.isActive
@UseExperimental(ExperimentalCoroutinesApi::class)
fun ReceiveChannel.uniqueOnly(scope: CoroutineScope): ReceiveChannel = scope.produce {
var previous: T? = null
for (current in this@uniqueOnly) {
if (!scope.isActive) {
cancel()
} else if (previous != current) {
previous = current
send(current)
}
}
}