From 1e42d783d499da590b0891b14bb3e169651d1dcb Mon Sep 17 00:00:00 2001
From: "exercism-solutions-syncer[bot]"
 <211797793+exercism-solutions-syncer[bot]@users.noreply.github.com>
Date: Wed, 6 Aug 2025 11:51:59 +0000
Subject: [PATCH] [Sync Iteration] elixir/rotational-cipher/2

---
 .../2/lib/rotational_cipher.ex                 | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 solutions/elixir/rotational-cipher/2/lib/rotational_cipher.ex

diff --git a/solutions/elixir/rotational-cipher/2/lib/rotational_cipher.ex b/solutions/elixir/rotational-cipher/2/lib/rotational_cipher.ex
new file mode 100644
index 0000000..322dcd9
--- /dev/null
+++ b/solutions/elixir/rotational-cipher/2/lib/rotational_cipher.ex
@@ -0,0 +1,18 @@
+defmodule RotationalCipher do
+  @doc """
+  Given a plaintext and amount to shift by, return a rotated string.
+
+  Example:
+  iex> RotationalCipher.rotate("Attack at dawn", 13)
+  "Nggnpx ng qnja"
+  """
+  @spec rotate(text :: String.t(), shift :: integer) :: String.t()
+  def rotate(text, shift) do
+    shift_char = fn
+      char when char in ?A..?Z -> <<?A + rem(char - ?A + shift, 26)>>
+      char when char in ?a..?z -> <<?a + rem(char - ?a + shift, 26)>>
+      char -> <<char>>
+    end
+    text |> String.to_charlist() |> Enum.map_join(shift_char)
+  end
+end