⚡ Bolt: Optimize string allocations in casing functions

.jules/bolt.md

@@ -0,0 +1,3 @@
+## 2024-05-24 - Avoid string collection allocations
+**Learning:** Rust's `.collect::<Vec<_>>().join("")` allocates an unnecessary intermediate vector, and `.to_lowercase().collect::<String>()` misses out on `Display` optimizations compared to `.to_lowercase().to_string()`.
+**Action:** Use `.collect::<String>()` directly when concatenating strings from an iterator, and `.to_string()` for char transformations to save memory and CPU cycles.

xdk-lib/src/casing.rs

@@ -32,8 +32,9 @@ impl Casing {
             Casing::Pascal => words
                 .iter()
                 .map(|w| pascal_case(w))
-                .collect::<Vec<_>>()
-                .join(""),
+                // Bolt optimization: avoiding `.collect::<Vec<_>>().join("")`
+                // prevents allocating an intermediate vector just to concatenate strings.
+                .collect::<String>(),
             Casing::Kebab => words.join("-").to_lowercase(),
             Casing::ScreamingSnake => words.join("_").to_uppercase(),
         }