From 29857bff0875c43e055e89d34bc0d616d5d7dc4f Mon Sep 17 00:00:00 2001
From: Linnea Gräf <nea@nea.moe>
Date: Wed, 29 Jan 2025 00:26:56 +0100
Subject: Load universe from json

---
 src/main/kotlin/util/iterutil.kt | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 src/main/kotlin/util/iterutil.kt

(limited to 'src/main/kotlin/util/iterutil.kt')

diff --git a/src/main/kotlin/util/iterutil.kt b/src/main/kotlin/util/iterutil.kt
new file mode 100644
index 0000000..7845b05
--- /dev/null
+++ b/src/main/kotlin/util/iterutil.kt
@@ -0,0 +1,36 @@
+package moe.nea.ultranotifier.util
+
+
+fun <T, K : Any> Sequence<T>.duplicatesBy(keyFunc: (T) -> K): Sequence<T> {
+	return object : Sequence<T> {
+		override fun iterator(): Iterator<T> {
+			val observed = HashSet<K>()
+			val oldIterator = this@duplicatesBy.iterator()
+
+			return object : Iterator<T> {
+				var next: T? = null
+				var hasNext = false
+				override fun hasNext(): Boolean {
+					if (hasNext) return true
+					while (oldIterator.hasNext()) {
+						val elem = oldIterator.next()
+						val key = keyFunc(elem)
+						if (observed.add(key))
+							continue
+						hasNext = true
+						next = elem
+					}
+					return hasNext
+				}
+
+				override fun next(): T {
+					if (!hasNext()) throw NoSuchElementException()
+					hasNext = false
+					val elem = next as T
+					next = null
+					return elem
+				}
+			}
+		}
+	}
+}
-- 
cgit