From c23299f135d49d2b2579d83699312c1085f20d25 Mon Sep 17 00:00:00 2001
From: Marcin Puc <marcin.e.puc@gmail.com>
Date: Tue, 13 Apr 2021 16:44:35 +0200
Subject: Add iterator.{empty, once, single}

---
 src/gleam/iterator.gleam | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

(limited to 'src')

diff --git a/src/gleam/iterator.gleam b/src/gleam/iterator.gleam
index 0b747df..c09901c 100644
--- a/src/gleam/iterator.gleam
+++ b/src/gleam/iterator.gleam
@@ -965,3 +965,37 @@ pub fn last(iterator: Iterator(element)) -> Result(element, Nil) {
   iterator
   |> reduce(fn(elem, _) { elem })
 }
+
+/// Creates an iterator that yields no elements.
+///
+/// ## Examples
+///
+///    > empty() |> to_list
+///    []
+///
+pub fn empty() -> Iterator(element) {
+  Iterator(stop)
+}
+
+/// Creates an iterator that yields exactly one element provided by calling the given function.
+///
+/// ## Examples
+///
+///    > once(fn() { 1 }) |> to_list
+///    [1]
+///
+pub fn once(f: fn() -> element) -> Iterator(element) {
+  fn() { Continue(f(), stop) }
+  |> Iterator
+}
+
+/// Creates an iterator that yields the given element exactly once.
+///
+/// ## Examples
+///
+///    > single(1) |> to_list
+///    [1]
+///
+pub fn single(elem: element) -> Iterator(element) {
+  once(fn() { elem })
+}
-- 
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