From d86237c4c07426d5f5df8fefd8f3e046b35ef4a4 Mon Sep 17 00:00:00 2001
From: Marcin Puc <marcin.e.puc@gmail.com>
Date: Mon, 8 Mar 2021 17:07:03 +0100
Subject: Add iterator.iterate

---
 src/gleam/iterator.gleam | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'src')

diff --git a/src/gleam/iterator.gleam b/src/gleam/iterator.gleam
index 9bbf9d0..f441859 100644
--- a/src/gleam/iterator.gleam
+++ b/src/gleam/iterator.gleam
@@ -494,3 +494,17 @@ pub fn find(
     Stop -> Error(Nil)
   }
 }
+
+/// Creates an iterator that inifinitely applies a function to a value.
+///
+/// ## Examples
+///
+///    > iterate(1, fn(n) { n * 3 }) |> take(5)
+///    [1, 3, 9, 27, 81]
+///
+pub fn iterate(
+  from initial: element,
+  with f: fn(element) -> element,
+) -> Iterator(element) {
+  unfold(initial, fn(element) { Next(element, f(element)) })
+}
-- 
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