From 9a5fc8168ad9aa79f2f33ff224349bf8135688fd Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Mon, 29 Jun 2026 21:30:15 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Bolt:=20[performance=20improvement]?=
 =?UTF-8?q?=20optimize=20string=20allocations=20in=20Casing=20module?=
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Replaced `.collect::<Vec<_>>().join("")` with `.collect::<String>()` for `Casing::Pascal` to avoid intermediate vector heap allocations.
Replaced `first.to_lowercase().collect::<String>()` with `first.to_lowercase().to_string()` in `camel_case` to leverage the `Display` implementation and avoid iterator collection overhead.

Co-authored-by: cloudesize67-cmd <237356855+cloudesize67-cmd@users.noreply.github.com>
---
 .jules/bolt.md        | 7 +++++++
 xdk-lib/src/casing.rs | 8 ++------
 2 files changed, 9 insertions(+), 6 deletions(-)
 create mode 100644 .jules/bolt.md

diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 00000000..f800c24e
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,7 @@
+## 2024-05-24 - Avoid `.collect::<Vec<_>>().join("")` for string concatenation in Rust
+**Learning:** Found a pattern where multiple strings are aggregated using `.collect::<Vec<_>>().join("")`, which introduces intermediate `Vec` allocations.
+**Action:** Use `.collect::<String>()` directly on an iterator of strings or string slices instead, which avoids the intermediate vector allocation when joining with an empty string.
+
+## 2024-05-24 - Use `to_lowercase().to_string()` over `to_lowercase().collect::<String>()`
+**Learning:** `char::to_lowercase()` returns an iterator (since a char can map to multiple chars), and using `.collect::<String>()` on it has collection overhead.
+**Action:** `char::to_lowercase()` implements `Display`, so prefer `.to_string()` over `.collect::<String>()` to leverage its Display implementation directly for string conversion.
diff --git a/xdk-lib/src/casing.rs b/xdk-lib/src/casing.rs
index 6463487e..bd04c567 100644
--- a/xdk-lib/src/casing.rs
+++ b/xdk-lib/src/casing.rs
@@ -29,11 +29,7 @@ impl Casing {
                     result
                 }
             }
-            Casing::Pascal => words
-                .iter()
-                .map(|w| pascal_case(w))
-                .collect::<Vec<_>>()
-                .join(""),
+            Casing::Pascal => words.iter().map(|w| pascal_case(w)).collect::<String>(),
             Casing::Kebab => words.join("-").to_lowercase(),
             Casing::ScreamingSnake => words.join("_").to_uppercase(),
         }
@@ -118,6 +114,6 @@ pub fn camel_case(value: &str) -> String {
     let mut chars = pascal.chars();
     match chars.next() {
         None => String::new(),
-        Some(first) => first.to_lowercase().collect::<String>() + chars.as_str(),
+        Some(first) => first.to_lowercase().to_string() + chars.as_str(),
     }
 }