From 837e24ab4b46751bbd294bf0c144245142a562f8 Mon Sep 17 00:00:00 2001
From: EdJoPaTo
 <rfc-conform-git-commit-email@funny-long-domain-label-everyone-hates-as-it-is-too-long.edjopato.de>
Date: Sat, 20 May 2023 01:49:43 +0200
Subject: [PATCH] perf(identifier): use pattern matching

way more efficient than manual slicing
---
 src/identifier.rs | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/identifier.rs b/src/identifier.rs
index 619fd67..adf4a54 100644
--- a/src/identifier.rs
+++ b/src/identifier.rs
@@ -23,12 +23,9 @@ pub type TreeIdentifierVec = Vec<usize>;
 /// assert_eq!(branch, []);
 /// assert_eq!(leaf, None);
 /// ```
-pub fn get_without_leaf(identifier: TreeIdentifier) -> (TreeIdentifier, Option<&usize>) {
-    let length = identifier.len();
-    let length_without_leaf = length.saturating_sub(1);
-
-    let branch = &identifier[0..length_without_leaf];
-    let leaf = identifier.get(length_without_leaf);
-
-    (branch, leaf)
+pub const fn get_without_leaf(identifier: TreeIdentifier) -> (TreeIdentifier, Option<&usize>) {
+    match identifier {
+        [branch @ .., leaf] => (branch, Some(leaf)),
+        [] => (&[] as &[usize], None),
+    }
 }