From 12df875131c2302f085ac2d6a69eff238c9fe04c Mon Sep 17 00:00:00 2001
From: Thibault Martinez <thibault@iota.org>
Date: Tue, 23 Jan 2024 12:55:57 +0100
Subject: [PATCH] Add `is_unique_sorted_by` and `is_sorted_by`

---
 iterator-sorted/CHANGELOG.md |  6 ++++++
 iterator-sorted/Cargo.toml   |  6 +++---
 iterator-sorted/src/lib.rs   | 25 +++++++++++++++++++------
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/iterator-sorted/CHANGELOG.md b/iterator-sorted/CHANGELOG.md
index a011ae1..ec3bc2f 100644
--- a/iterator-sorted/CHANGELOG.md
+++ b/iterator-sorted/CHANGELOG.md
@@ -19,6 +19,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Security -->
 
+## 0.2.0 - 2024-01-23
+
+### Added
+
+- `is_unique_sorted_by` and `is_sorted_by`;
+
 ## 0.1.0 - 2022-01-17
 
 ### Added
diff --git a/iterator-sorted/Cargo.toml b/iterator-sorted/Cargo.toml
index 755f93b..63ad17a 100644
--- a/iterator-sorted/Cargo.toml
+++ b/iterator-sorted/Cargo.toml
@@ -1,11 +1,11 @@
 [package]
 name = "iterator-sorted"
-version = "0.1.0"
-authors = [ "IOTA Stiftung" ]
+version = "0.2.0"
+authors = ["IOTA Stiftung"]
 edition = "2021"
 description = "Stable functions for checking iterator sorting."
 readme = "README.md"
 repository = "https://github.com/iotaledger/common-rs"
 license = "Apache-2.0"
-keywords = [ "iota", "iterator", "sorted" ]
+keywords = ["iota", "iterator", "sorted"]
 homepage = "https://www.iota.org"
diff --git a/iterator-sorted/src/lib.rs b/iterator-sorted/src/lib.rs
index 64a2360..a82235f 100644
--- a/iterator-sorted/src/lib.rs
+++ b/iterator-sorted/src/lib.rs
@@ -8,15 +8,18 @@
 
 use core::{cmp::Ordering, iter::Iterator};
 
-/// Checks if an iterator yields ordered and unique values.
-pub fn is_unique_sorted<T: Ord, I: Iterator<Item = T>>(mut iterator: I) -> bool {
+/// Checks if an iterator yields ordered and unique values based on a given comparator.
+pub fn is_unique_sorted_by<T: Ord, I: Iterator<Item = T>, F: FnMut(&T, &T) -> Ordering>(
+    mut iterator: I,
+    mut cmp: F,
+) -> bool {
     let mut previous = match iterator.next() {
         Some(e) => e,
         None => return true,
     };
 
     for curr in iterator {
-        if previous.cmp(&curr) != Ordering::Less {
+        if cmp(&previous, &curr) != Ordering::Less {
             return false;
         }
         previous = curr;
@@ -25,15 +28,20 @@ pub fn is_unique_sorted<T: Ord, I: Iterator<Item = T>>(mut iterator: I) -> bool
     true
 }
 
-/// Checks if an iterator yields ordered values.
-pub fn is_sorted<T: Ord, I: Iterator<Item = T>>(mut iterator: I) -> bool {
+/// Checks if an iterator yields ordered and unique values.
+pub fn is_unique_sorted<T: Ord, I: Iterator<Item = T>>(iterator: I) -> bool {
+    is_unique_sorted_by(iterator, T::cmp)
+}
+
+/// Checks if an iterator yields ordered values based on a given comparator.
+pub fn is_sorted_by<T: Ord, I: Iterator<Item = T>, F: FnMut(&T, &T) -> Ordering>(mut iterator: I, mut cmp: F) -> bool {
     let mut previous = match iterator.next() {
         Some(e) => e,
         None => return true,
     };
 
     for curr in iterator {
-        if previous.cmp(&curr) == Ordering::Greater {
+        if cmp(&previous, &curr) == Ordering::Greater {
             return false;
         }
         previous = curr;
@@ -41,3 +49,8 @@ pub fn is_sorted<T: Ord, I: Iterator<Item = T>>(mut iterator: I) -> bool {
 
     true
 }
+
+/// Checks if an iterator yields ordered values.
+pub fn is_sorted<T: Ord, I: Iterator<Item = T>>(iterator: I) -> bool {
+    is_sorted_by(iterator, T::cmp)
+}