⚡ Bolt: [performance improvement] Avoid intermediate Vector allocations during casing conversions

.jules/bolt.md

@@ -0,0 +1,3 @@
+## 2024-05-18 - Avoid unnecessary allocations when applying casing rules
+**Learning:** Found string formatting logic in `xdk-lib/src/casing.rs` causing intermediate allocations. E.g., `words.iter().map(|w| pascal_case(w)).collect::<Vec<_>>().join("")` creates an unnecessary `Vec` allocation before `.join("")` and can be simplified using an iterator structure like string concatenation. Similarly, converting a char to a lowercase string should not use `collect::<String>()` when `to_string()` avoids iterator overhead.
+**Action:** Replace `collect::<Vec<_>>().join("")` with `fold` or looping to avoid creating intermediate `Vec` instances. Replace `.to_lowercase().collect::<String>()` with `.to_lowercase().to_string()`.

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(),
     }
 }