From 61c0afb9abb9ab27a9a881e58dae178a8ce50710 Mon Sep 17 00:00:00 2001
From: Jonas Wanke <contact@jonas-wanke.com>
Date: Wed, 11 Dec 2024 20:56:52 +0100
Subject: [PATCH] =?UTF-8?q?Add=20list.windows(=E2=80=A6)?=
MIME-Version: 1.0
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---
 packages_v5/example.candy | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/packages_v5/example.candy b/packages_v5/example.candy
index 3696367ce..2e6508e9c 100644
--- a/packages_v5/example.candy
+++ b/packages_v5/example.candy
@@ -415,6 +415,25 @@ fun map[T, R](list: List[T], transform: (T) R) List[R] {
     result.append(transform(item))
   })
 }
+fun windows[T](list: List[T], windowLength: Int) List[List[T]] {
+  # Returns a list over all contiguous windows of length `windowLength`.
+  #
+  # The windows overlap. If the `list` is shorter than `windowLength`, the
+  # resulting list is empty.
+  needs(windowLength.isPositive())
+
+  list.windowsHelper(windowLength, listOf[List[T]]())
+}
+fun windowsHelper[T](list: List[T], windowLength: Int, resultSoFar: List[List[T]]) List[List[T]] {
+  let index = resultSoFar.length()
+  switch index.isLessThanOrEqualTo(list.length().subtract(windowLength)) {
+    true => list.windowsHelper(
+      windowLength,
+      resultSoFar.append(list.getRange(index, index.add(windowLength))),
+    ),
+    false => resultSoFar,
+  }
+}
 impl[T: ToText] List[T]: ToText {
   fun toText(self: List[T]) Text {
     let items = self.map((item: T) { item.toText() })