From 9f90d0153a0cd8b1e3cd13a5b67ed6600e889699 Mon Sep 17 00:00:00 2001
From: tuguzT <timurka.tugushev@gmail.com>
Date: Thu, 7 Sep 2023 21:41:17 +0300
Subject: [PATCH] Add new operation to shuffle heterogenous list

---
 src/ops/mod.rs     |  2 ++
 src/ops/shuffle.rs | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)
 create mode 100644 src/ops/shuffle.rs

diff --git a/src/ops/mod.rs b/src/ops/mod.rs
index ef66f69..0dc62c6 100644
--- a/src/ops/mod.rs
+++ b/src/ops/mod.rs
@@ -14,6 +14,7 @@ pub use self::{
     remove::Remove,
     remove_many::{RemoveMany, RemoveManyIndex},
     reverse::Reverse,
+    shuffle::Shuffle,
     to_ref::ToRef,
     unzip::Unzip,
     zip::Zip,
@@ -32,6 +33,7 @@ mod prepend;
 mod remove;
 mod remove_many;
 mod reverse;
+mod shuffle;
 mod to_ref;
 mod unzip;
 mod zip;
diff --git a/src/ops/shuffle.rs b/src/ops/shuffle.rs
new file mode 100644
index 0000000..8eb36d2
--- /dev/null
+++ b/src/ops/shuffle.rs
@@ -0,0 +1,38 @@
+use crate::{HList, Nil};
+
+use super::{RemoveMany, RemoveManyIndex};
+
+/// Shuffle current heterogenous list, or change order of its elements.
+///
+/// Index generic parameter is used to determine a way to construct shuffled list,
+/// because there may be more than one if type of elements is not unique.
+pub trait Shuffle<T, I>: RemoveMany<T, I, Remainder = Nil>
+where
+    T: HList,
+    I: RemoveManyIndex,
+{
+    /// Shuffles current heterogenous list, or changes order of its elements.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use hlist2::{hlist, HList, ops::Shuffle};
+    ///
+    /// let list = hlist![1, 2.0, true, "hello world"];
+    /// let shuffled: HList![bool, i32, &str, f32] = list.shuffle();
+    /// assert_eq!(shuffled, hlist![true, 1, "hello world", 2.0]);
+    /// ```
+    fn shuffle(self) -> T;
+}
+
+impl<T, L, I> Shuffle<L, I> for T
+where
+    L: HList,
+    T: RemoveMany<L, I, Remainder = Nil>,
+    I: RemoveManyIndex,
+{
+    fn shuffle(self) -> L {
+        let (list, _) = self.remove_many();
+        list
+    }
+}