⚡ Bolt: [performance improvement] Avoid intermediate Vector allocations in iterators and strings

.jules/bolt.md

@@ -0,0 +1,3 @@
+## 2024-06-25 - [Rust Iterator Allocations]
+**Learning:** In Rust, avoid intermediate allocations by iterating directly over iterator sources (like `.split()`) rather than calling `.collect::<Vec<_>>().into_iter()`. Also, use character-based splits (e.g., `.split('\n')`) instead of string-based splits (e.g., `.split("\n")`) for single characters. Furthermore, when transforming and aggregating collections of strings, use `.collect::<String>()` instead of `.collect::<Vec<_>>().join("")` for string concatenation to prevent intermediate vector allocations.
+**Action:** When working with iterators and strings in Rust, check for intermediate allocations that can be avoided by directly using `collect::<String>()` or dropping `collect::<Vec<_>>().into_iter()` from iterator chains. Use `char` arguments for single-character string functions to enhance performance.

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 parts = line.split(' ').collect::<Vec<&str>>();
+            if parts.len() == 2 {
+                log_info!("{} {}", parts[0], parts[1].magenta());
+            }
+        });
         println!();
     }
 

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(),
         }