io.pixeloutlaw.minecraft.spigot.Prerequisites.kt Maven / Gradle / Ivy
/*
* This file is part of MythicDrops, licensed under the MIT License.
*
* Copyright (C) 2020 Richard Harrah
*
* Permission is hereby granted, free of charge,
* to any person obtaining a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or
* substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
* OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package io.pixeloutlaw.minecraft.spigot
/**
* Simple typealias for a function that returns a boolean.
*/
internal fun interface Prerequisite {
fun invoke(): Boolean
}
internal class OrPrerequisite internal constructor() : Prerequisite {
private val prerequisites: MutableList = mutableListOf()
override fun invoke(): Boolean =
prerequisites.fold(true) { accumulator: Boolean, prerequisite: Prerequisite ->
accumulator || prerequisite.invoke()
}
fun prerequisite(prerequisite: Prerequisite) {
prerequisites.add(prerequisite)
}
}
/**
* Holds a collection of functions that return a boolean.
*/
internal class Prerequisites internal constructor() {
internal val prereqs: MutableList = mutableListOf()
fun invoke(): Boolean =
prereqs.fold(true) { accumulator: Boolean, prerequisite: Prerequisite ->
accumulator && prerequisite.invoke()
}
fun prerequisite(prerequisite: Prerequisite) {
prereqs.add(prerequisite)
}
}
/**
* Constructs a [Prerequisites] instance and invokes it after configuring it via [block].
*/
internal fun prerequisites(block: Prerequisites.() -> Unit): Boolean = Prerequisites().apply { block() }.invoke()
/**
* Constructs an [OrPrerequisite] and configures it ready to be passed to [Prerequisites.prerequisite].
*/
internal fun orPrerequisite(block: OrPrerequisite.() -> Unit): Prerequisite = OrPrerequisite().apply(block)