brigadier wip

7 files changed, 506 insertions, 1 deletions

diff --git a/build.gradle.kts b/build.gradle.kts
index e41aa513..4dc253a9 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -139,6 +139,8 @@ dependencies {
 		annotationProcessor("org.projectlombok:lombok:1.18.24")
 		"oneconfigAnnotationProcessor"("org.projectlombok:lombok:1.18.24")
 
+		shadowImplementation("com.mojang:brigadier:1.0.18")
+
 		shadowImplementation("org.spongepowered:mixin:0.7.11-SNAPSHOT") {
 				isTransitive = false // Dependencies of mixin are already bundled by minecraft
 		}
@@ -233,6 +235,7 @@ tasks.shadowJar {
 		from(kotlinDependencyCollectionJar)
 		dependsOn(kotlinDependencyCollectionJar)
 		fun relocate(name: String) = relocate(name, "io.github.moulberry.notenoughupdates.deps.$name")
+		relocate("com.mojang.brigadier")
 }
 
 tasks.assemble.get().dependsOn(remapJar)
diff --git a/src/main/java/io/github/moulberry/notenoughupdates/commands/dev/DevTestCommand.java b/src/main/java/io/github/moulberry/notenoughupdates/commands/dev/DevTestCommand.java
index cf266dca..3a2c39ca 100644
--- a/src/main/java/io/github/moulberry/notenoughupdates/commands/dev/DevTestCommand.java
+++ b/src/main/java/io/github/moulberry/notenoughupdates/commands/dev/DevTestCommand.java
@@ -19,6 +19,8 @@
 
 package io.github.moulberry.notenoughupdates.commands.dev;
 
+import com.mojang.brigadier.CommandDispatcher;
+import com.mojang.brigadier.builder.LiteralArgumentBuilder;
 import io.github.moulberry.notenoughupdates.BuildFlags;
 import io.github.moulberry.notenoughupdates.NotEnoughUpdates;
 import io.github.moulberry.notenoughupdates.commands.ClientCommandBase;
@@ -49,9 +51,12 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
 
+import static com.mojang.brigadier.arguments.IntegerArgumentType.integer;
+import static com.mojang.brigadier.builder.RequiredArgumentBuilder.argument;
+
 public class DevTestCommand extends ClientCommandBase {
 
-	private static final List<String> DEV_TESTERS =
+	public static final List<String> DEV_TESTERS =
 		Arrays.asList(
 			"d0e05de7-6067-454d-beae-c6d19d886191", // moulberry
 			"66502b40-6ac1-4d33-950d-3df110297aab", // lucycoconut
diff --git a/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/EnumArgumentType.kt b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/EnumArgumentType.kt
new file mode 100644
index 00000000..14b6ed6e
--- /dev/null
+++ b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/EnumArgumentType.kt
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2023 NotEnoughUpdates contributors
+ *
+ * This file is part of NotEnoughUpdates.
+ *
+ * NotEnoughUpdates is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * NotEnoughUpdates 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with NotEnoughUpdates. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package io.github.moulberry.notenoughupdates.util.brigadier
+
+import com.mojang.brigadier.LiteralMessage
+import com.mojang.brigadier.StringReader
+import com.mojang.brigadier.arguments.ArgumentType
+import com.mojang.brigadier.context.CommandContext
+import com.mojang.brigadier.exceptions.SimpleCommandExceptionType
+import com.mojang.brigadier.suggestion.Suggestions
+import com.mojang.brigadier.suggestion.SuggestionsBuilder
+import java.util.concurrent.CompletableFuture
+
+class EnumArgumentType<T : Enum<T>>(
+    val values: List<T>
+) : ArgumentType<T> {
+    companion object {
+        @JvmStatic
+        fun <T : Enum<T>> enum(values: Array<T>) = EnumArgumentType(values.toList())
+
+        inline fun <reified T : Enum<T>> enum() = enum(enumValues<T>())
+    }
+
+    override fun getExamples(): Collection<String> {
+        return values.map { it.name }
+    }
+
+    override fun <S : Any?> listSuggestions(
+        context: CommandContext<S>,
+        builder: SuggestionsBuilder
+    ): CompletableFuture<Suggestions> {
+
+        examples
+            .filter {builder.remaining.isBlank() ||  it.startsWith(builder.remaining, ignoreCase = true) }
+            .forEach { builder.suggest(it) }
+        return builder.buildFuture()
+    }
+
+    private val invalidEnum =
+        SimpleCommandExceptionType(LiteralMessage("Expected one of: ${values.joinToString(", ")}"))
+
+    override fun parse(reader: StringReader): T {
+        val enumName = reader.readString()
+        return values.find { enumName == it.name }
+            ?: throw invalidEnum.createWithContext(reader)
+    }
+}
diff --git a/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/RestArgumentType.kt b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/RestArgumentType.kt
new file mode 100644
index 00000000..adfdae6a
--- /dev/null
+++ b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/RestArgumentType.kt
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2023 NotEnoughUpdates contributors
+ *
+ * This file is part of NotEnoughUpdates.
+ *
+ * NotEnoughUpdates is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * NotEnoughUpdates 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with NotEnoughUpdates. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package io.github.moulberry.notenoughupdates.util.brigadier
+
+import com.mojang.brigadier.StringReader
+import com.mojang.brigadier.arguments.ArgumentType
+
+object RestArgumentType : ArgumentType<String> {
+    override fun parse(reader: StringReader): String {
+        val remaining = reader.remaining
+        reader.cursor += remaining.length
+        return remaining
+    }
+}
diff --git a/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/Rome.kt b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/Rome.kt
new file mode 100644
index 00000000..7f8f3f74
--- /dev/null
+++ b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/Rome.kt
@@ -0,0 +1,241 @@
+/*
+ * Copyright (C) 2023 Linnea Gräf
+ *
+ * This file is part of NotEnoughUpdates.
+ *
+ * NotEnoughUpdates is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * NotEnoughUpdates 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with NotEnoughUpdates. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package io.github.moulberry.notenoughupdates.util.brigadier
+
+import com.mojang.brigadier.CommandDispatcher
+import com.mojang.brigadier.ParseResults
+import com.mojang.brigadier.arguments.StringArgumentType.string
+import com.mojang.brigadier.exceptions.CommandSyntaxException
+import com.mojang.brigadier.suggestion.Suggestions
+import io.github.moulberry.notenoughupdates.BuildFlags
+import io.github.moulberry.notenoughupdates.NotEnoughUpdates
+import io.github.moulberry.notenoughupdates.autosubscribe.NEUAutoSubscribe
+import io.github.moulberry.notenoughupdates.commands.dev.DevTestCommand.DEV_TESTERS
+import io.github.moulberry.notenoughupdates.core.config.GuiPositionEditor
+import io.github.moulberry.notenoughupdates.core.util.MiscUtils
+import io.github.moulberry.notenoughupdates.miscfeatures.FishingHelper
+import io.github.moulberry.notenoughupdates.miscfeatures.customblockzones.CustomBiomes
+import io.github.moulberry.notenoughupdates.miscfeatures.customblockzones.LocationChangeEvent
+import io.github.moulberry.notenoughupdates.miscgui.GuiPriceGraph
+import io.github.moulberry.notenoughupdates.miscgui.minionhelper.MinionHelperManager
+import io.github.moulberry.notenoughupdates.util.LRUCache
+import io.github.moulberry.notenoughupdates.util.PronounDB
+import io.github.moulberry.notenoughupdates.util.SBInfo
+import io.github.moulberry.notenoughupdates.util.TabListUtils
+import io.github.moulberry.notenoughupdates.util.brigadier.EnumArgumentType.Companion.enum
+import net.minecraft.client.Minecraft
+import net.minecraft.client.gui.GuiScreen
+import net.minecraft.command.CommandBase
+import net.minecraft.command.ICommandSender
+import net.minecraft.entity.player.EntityPlayer
+import net.minecraft.launchwrapper.Launch
+import net.minecraft.util.BlockPos
+import net.minecraft.util.ChatComponentText
+import net.minecraft.util.EnumChatFormatting
+import net.minecraft.util.EnumChatFormatting.GOLD
+import net.minecraft.util.EnumChatFormatting.RED
+import net.minecraft.util.EnumParticleTypes
+import net.minecraftforge.client.ClientCommandHandler
+import net.minecraftforge.common.MinecraftForge
+import java.util.concurrent.CompletableFuture
+
+@NEUAutoSubscribe
+object Rome {
+    val dispatcher = CommandDispatcher<DefaultSource>()
+    private val parseText =
+        LRUCache.memoize<Pair<ICommandSender, String>, ParseResults<DefaultSource>>({ (sender, text) ->
+            dispatcher.parse(text, sender)
+        }, 1)
+
+    init {
+        dispatcher.register(literal("neudevtest2") {
+            requires {
+                DEV_TESTERS.contains((it as? EntityPlayer)?.uniqueID?.toString())
+                        || Launch.blackboard.get("fml.deobfuscatedEnvironment") as Boolean
+            }
+            thenLiteralExecute("profileinfo") {
+                val currentProfile = SBInfo.getInstance().currentProfile
+                val gamemode = SBInfo.getInstance().getGamemodeForProfile(currentProfile)
+                reply("${GOLD}You are on Profile $currentProfile with the mode $gamemode")
+            }
+            thenLiteralExecute("buildflags") {
+                reply("BuildFlags: \n" +
+                        BuildFlags.getAllFlags().entries
+                            .joinToString(("\n")) { (key, value) -> " + $key - $value" })
+            }
+            thenLiteral("exteditor") {
+                thenExecute {
+                    reply("Your external editor is: §Z${NotEnoughUpdates.INSTANCE.config.hidden.externalEditor}")
+                }
+                thenArgument("editor", string()) { newEditor ->
+                    thenExecute {
+                        NotEnoughUpdates.INSTANCE.config.hidden.externalEditor = this[newEditor]
+                        reply("You changed your external editor to: §Z${this[newEditor]}")
+                    }
+                }
+            }
+            thenLiteral("pricetest") {
+                thenExecute {
+                    NotEnoughUpdates.INSTANCE.manager.auctionManager.updateBazaar()
+                }
+                thenArgument("item", string()) { item ->
+                    thenExecute {
+                        NotEnoughUpdates.INSTANCE.openGui = GuiPriceGraph(this[item])
+                    }
+                }
+            }
+            thenLiteralExecute("zone") {
+                val target = Minecraft.getMinecraft().objectMouseOver.blockPos
+                    ?: Minecraft.getMinecraft().thePlayer.position
+                val zone = CustomBiomes.INSTANCE.getSpecialZone(target)
+                listOf(
+                    ChatComponentText("Showing Zone Info for: $target"),
+                    ChatComponentText("Zone: " + (zone?.name ?: "null")),
+                    ChatComponentText("Location: " + SBInfo.getInstance().getLocation()),
+                    ChatComponentText("Biome: " + CustomBiomes.INSTANCE.getCustomBiome(target))
+                ).forEach { component ->
+                    reply(component)
+                }
+                MinecraftForge.EVENT_BUS.post(
+                    LocationChangeEvent(
+                        SBInfo.getInstance().getLocation(), SBInfo
+                            .getInstance()
+                            .getLocation()
+                    )
+                )
+            }
+            thenLiteralExecute("positiontest") {
+                NotEnoughUpdates.INSTANCE.openGui = GuiPositionEditor()
+            }
+            thenLiteral("pt") {
+                thenArgument("particle", enum<EnumParticleTypes>()) { particle ->
+                    thenExecute {
+                        FishingHelper.type = this[particle]
+                        reply("Fishing particles set to ${FishingHelper.type}")
+                    }
+                }
+            }
+            thenLiteralExecute("dev") {
+                NotEnoughUpdates.INSTANCE.config.hidden.dev = !NotEnoughUpdates.INSTANCE.config.hidden.dev
+                reply("§e[NEU] Dev mode " + if (NotEnoughUpdates.INSTANCE.config.hidden.dev) "§aenabled" else "§cdisabled")
+            }
+            thenLiteralExecute("saveconfig") {
+                NotEnoughUpdates.INSTANCE.saveConfig()
+                reply("Config saved")
+            }
+            thenLiteralExecute("searchmode") {
+                NotEnoughUpdates.INSTANCE.config.hidden.firstTimeSearchFocus = true
+                reply(EnumChatFormatting.AQUA.toString() + "I would never search")
+            }
+            thenLiteralExecute("bluehair") {
+                PronounDB.test()
+            }
+            thenLiteral("opengui") {
+                thenArgument("class", string()) { className ->
+                    thenExecute {
+                        try {
+                            NotEnoughUpdates.INSTANCE.openGui =
+                                Class.forName(this[className]).newInstance() as GuiScreen
+                            reply("Opening gui: " + NotEnoughUpdates.INSTANCE.openGui)
+                        } catch (e: Exception) {
+                            e.printStackTrace()
+                            reply("Failed to open this GUI.")
+                        }
+                    }
+                }
+            }
+            thenLiteralExecute("center") {
+                val x = Math.floor(Minecraft.getMinecraft().thePlayer.posX) + 0.5f
+                val z = Math.floor(Minecraft.getMinecraft().thePlayer.posZ) + 0.5f
+                Minecraft.getMinecraft().thePlayer.setPosition(x, Minecraft.getMinecraft().thePlayer.posY, z)
+                reply("Literal hacks")
+            }
+            thenLiteral("minion") {
+                thenArgument("args", RestArgumentType) { arg ->
+                    thenExecute {
+                        MinionHelperManager.getInstance().handleCommand(arrayOf("minion") + this[arg].split(" "))
+                    }
+                }
+            }
+            thenLiteralExecute("copytablist") {
+                val tabList = TabListUtils.getTabList().joinToString("\n", postfix = "\n")
+                MiscUtils.copyToClipboard(tabList)
+                reply("Copied tablist to clipboard!")
+            }
+        })
+        updateHooks()
+    }
+
+    fun updateHooks() = registerHooks(ClientCommandHandler.instance)
+
+    fun registerHooks(handler: ClientCommandHandler) {
+        dispatcher.root.children.forEach { commandNode ->
+            if (commandNode.name in handler.commands) return@forEach
+            handler.registerCommand(object : CommandBase() {
+                override fun getCommandName(): String {
+                    return commandNode.name
+                }
+
+                override fun getCommandUsage(sender: ICommandSender): String {
+                    return dispatcher.getAllUsage(commandNode, sender, true).joinToString("\n")
+                }
+
+                fun getText(args: Array<out String>) = "${commandNode.name} ${args.joinToString(" ")}"
+
+                override fun processCommand(sender: ICommandSender, args: Array<out String>) {
+                    val results = parseText.apply(sender to getText(args).trim())
+                    try {
+                        dispatcher.execute(results)
+                    } catch (syntax: CommandSyntaxException) {
+                        sender.addChatMessage(ChatComponentText("${RED}${syntax.message}"))
+                    }
+                }
+
+                var lastCompletionText: String? = null
+                var lastCompletion: CompletableFuture<Suggestions>? = null
+
+                override fun addTabCompletionOptions(
+                    sender: ICommandSender,
+                    args: Array<out String>,
+                    pos: BlockPos
+                ): List<String> {
+                    val originalText = getText(args)
+                    var lc: CompletableFuture<Suggestions>? = null
+                    if (lastCompletionText == originalText) {
+                        lc = lastCompletion
+                    }
+                    if (lc == null) {
+                        lastCompletion?.cancel(true)
+                        val results = parseText.apply(sender to originalText)
+                        lc = dispatcher.getCompletionSuggestions(results)
+                    }
+                    lastCompletion = lc
+                    lastCompletionText = originalText
+                    val suggestions = lastCompletion?.getNow(null) ?: return emptyList()
+                    return suggestions.list.map { it.text }
+                }
+
+                override fun canCommandSenderUseCommand(sender: ICommandSender): Boolean {
+                    return true
+                }
+            })
+        }
+    }
+}
diff --git a/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/dsl.kt b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/dsl.kt
new file mode 100644
index 00000000..b054f6d9
--- /dev/null
+++ b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/brigadier/dsl.kt
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2023 Linnea Gräf
+ *
+ * This file is part of NotEnoughUpdates.
+ *
+ * NotEnoughUpdates is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * NotEnoughUpdates 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with NotEnoughUpdates. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package io.github.moulberry.notenoughupdates.util.brigadier
+
+import com.mojang.brigadier.arguments.ArgumentType
+import com.mojang.brigadier.builder.ArgumentBuilder
+import com.mojang.brigadier.builder.LiteralArgumentBuilder
+import com.mojang.brigadier.builder.RequiredArgumentBuilder
+import com.mojang.brigadier.context.CommandContext
+import io.github.moulberry.notenoughupdates.util.iterate
+import net.minecraft.command.ICommandSender
+import net.minecraft.util.ChatComponentText
+import net.minecraft.util.IChatComponent
+import java.lang.reflect.ParameterizedType
+import java.lang.reflect.Type
+import java.lang.reflect.TypeVariable
+
+
+typealias DefaultSource = ICommandSender
+
+fun literal(
+    name: String,
+    block: LiteralArgumentBuilder<DefaultSource>.() -> Unit
+): LiteralArgumentBuilder<DefaultSource> =
+    LiteralArgumentBuilder.literal<DefaultSource>(name).also(block)
+
+private fun normalizeGeneric(argument: Type): Class<*> {
+    return if (argument is Class<*>) {
+        argument
+    } else if (argument is TypeVariable<*>) {
+        normalizeGeneric(argument.bounds[0])
+    } else if (argument is ParameterizedType) {
+        normalizeGeneric(argument.rawType)
+    } else {
+        Any::class.java
+    }
+}
+
+data class TypeSafeArg<T : Any>(val name: String, val argument: ArgumentType<T>) {
+    val argClass by lazy {
+        argument.javaClass
+            .iterate<Class<in ArgumentType<T>>> {
+                it.superclass
+            }
+            .flatMap {
+                it.genericInterfaces.toList()
+            }
+            .filterIsInstance<ParameterizedType>()
+            .find { it.rawType == ArgumentType::class.java }!!
+            .let {
+                normalizeGeneric(it.actualTypeArguments[0])
+            }
+    }
+
+    @JvmName("getWithThis")
+    fun <S> CommandContext<S>.get(): T =
+        get(this)
+
+
+    fun <S> get(ctx: CommandContext<S>): T {
+        return ctx.getArgument(name, argClass) as T
+    }
+}
+
+fun <T : ICommandSender, C : CommandContext<T>> C.reply(component: IChatComponent) {
+    source.addChatMessage(component)
+}
+
+fun <T : ICommandSender, C : CommandContext<T>> C.reply(text: String) {
+    source.addChatMessage(ChatComponentText(text))
+}
+
+operator fun <T : Any, C : CommandContext<*>> C.get(arg: TypeSafeArg<T>): T {
+    return arg.get(this)
+}
+
+
+fun <T : Any> argument(
+    name: String,
+    argument: ArgumentType<T>,
+    block: RequiredArgumentBuilder<DefaultSource, T>.(TypeSafeArg<T>) -> Unit
+): RequiredArgumentBuilder<DefaultSource, T> =
+    RequiredArgumentBuilder.argument<DefaultSource, T>(name, argument).also { block(it, TypeSafeArg(name, argument)) }
+
+fun <T : ArgumentBuilder<DefaultSource, T>, AT : Any> T.thenArgument(
+    name: String,
+    argument: ArgumentType<AT>,
+    block: RequiredArgumentBuilder<DefaultSource, AT>.(TypeSafeArg<AT>) -> Unit
+): T = then(argument(name, argument, block))
+
+
+fun <T : ArgumentBuilder<DefaultSource, T>> T.thenLiteral(
+    name: String,
+    block: LiteralArgumentBuilder<DefaultSource>.() -> Unit
+): T =
+    then(literal(name, block))
+
+
+fun <T : ArgumentBuilder<DefaultSource, T>> T.thenLiteralExecute(
+    name: String,
+    block: CommandContext<DefaultSource>.() -> Unit
+): T =
+    thenLiteral(name) {
+        thenExecute(block)
+    }
+
+fun <T : ArgumentBuilder<DefaultSource, T>> T.then(node: ArgumentBuilder<DefaultSource, *>, block: T.() -> Unit): T =
+    then(node).also(block)
+
+fun <T : ArgumentBuilder<DefaultSource, T>> T.thenExecute(block: CommandContext<DefaultSource>.() -> Unit): T =
+    executes {
+        block(it)
+        1
+    }
+
+
diff --git a/src/main/kotlin/io/github/moulberry/notenoughupdates/util/iterate.kt b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/iterate.kt
new file mode 100644
index 00000000..bcfe11aa
--- /dev/null
+++ b/src/main/kotlin/io/github/moulberry/notenoughupdates/util/iterate.kt
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2023 NotEnoughUpdates contributors
+ *
+ * This file is part of NotEnoughUpdates.
+ *
+ * NotEnoughUpdates is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * NotEnoughUpdates 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with NotEnoughUpdates. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package io.github.moulberry.notenoughupdates.util
+
+fun <T : Any> T.iterate(evolve: (T) -> T?): Sequence<T> = sequence {
+    var pointer: T? = this@iterate
+    while (pointer != null) {
+        yield(pointer)
+        pointer = evolve(pointer)
+    }
+}