From f9bb16a743a2c32c9ed178e8524edf743fb8e2dc Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Thu, 7 May 2026 21:24:35 +0000
Subject: [PATCH] =?UTF-8?q?=E2=9A=A1=20Bolt:=20[performance=20improvement]?=
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- Optimized string splitting and concatenation by avoiding intermediate vector allocations in `xdk-build/src/python.rs` and `xdk-lib/src/casing.rs`.
- Documented findings in `.jules/bolt.md`.

Co-authored-by: cloudesize67-cmd <237356855+cloudesize67-cmd@users.noreply.github.com>
---
 .jules/bolt.md          |  3 +++
 xdk-build/src/python.rs | 16 ++++++----------
 xdk-lib/src/casing.rs   |  6 +-----
 3 files changed, 10 insertions(+), 15 deletions(-)
 create mode 100644 .jules/bolt.md

diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 00000000..b7df5591
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-05-24 - Avoid intermediate Vec allocations for string iteration and concatenation
+**Learning:** The codebase contained patterns where strings were split and collected into a `Vec` only to be iterated over, or mapped strings were collected into a `Vec` and then joined into a single string. These create unnecessary intermediate allocations that slow down performance. Furthermore, single-character splits were using string literals (e.g., `.split(" ")`) which is less efficient than using character literals (e.g., `.split(' ')`).
+**Action:** When transforming and aggregating strings or splitting and iterating over them, avoid `.collect::<Vec<_>>()`. Iterate directly over iterators, use `.collect::<String>()` for concatenation, and use character-based splits for single characters.
diff --git a/xdk-build/src/python.rs b/xdk-build/src/python.rs
index 1d15d6f0..65d012c9 100644
--- a/xdk-build/src/python.rs
+++ b/xdk-build/src/python.rs
@@ -159,16 +159,12 @@ fn run_formatter(output_dir: &Path, venv_python_path: &Path, script_path: &Path)
     let stdout = String::from_utf8_lossy(&output.stdout);
     if !stdout.trim().is_empty() {
         println!();
-        stdout
-            .split("\n")
-            .collect::<Vec<&str>>()
-            .into_iter()
-            .for_each(|line| {
-                let parts = line.split(" ").collect::<Vec<&str>>();
-                if parts.len() == 2 {
-                    log_info!("{} {}", parts[0], parts[1].magenta());
-                }
-            });
+        stdout.split('\n').for_each(|line| {
+            let mut parts = line.split(' ');
+            if let (Some(part0), Some(part1), None) = (parts.next(), parts.next(), parts.next()) {
+                log_info!("{} {}", part0, part1.magenta());
+            }
+        });
         println!();
     }
 
diff --git a/xdk-lib/src/casing.rs b/xdk-lib/src/casing.rs
index 6463487e..0ee4c0d2 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(),
         }