⚡ Bolt: [optimize range selection string extraction in LSP]

.jules/bolt.md

@@ -20,6 +20,4 @@
 ## 2024-08-01 - Bytecode Disassembler String Allocation Optimization
 **Learning:** Formatting directly into a string buffer inside a tight loop with `write!(buffer, ...)` avoids unnecessary string heap allocations compared to `buffer.push_str(&format!(...))`.
 **Action:** Always prefer formatting directly into the target String buffer when concatenating strings in loops in performance-sensitive paths like debuggers or disassemblers.
-## 2024-11-20 - [SQLite Query Mapping Optimization]
-**Learning:** In dynamically typed environments, unconditionally casting database query results to strings (e.g., via `row.get::<_, String>`) before mapping them to internal types is highly inefficient and creates bugs. Direct iteration matching over native database memory representations (like `rusqlite::types::ValueRef`) preserves typing metadata and prevents unnecessary allocations.
-**Action:** When extracting data from a database adapter layer to dynamic variants, use exact matching (e.g., `ValueRef::Integer`) and initialize the destination collections using `.with_capacity()` based on the column count.
+

tools/lsp/src/lib.rs

@@ -1291,11 +1291,18 @@ impl LanguageServer for Backend {
         let start = range.start.line as usize;
         let end = (range.end.line as usize).min(lines.len() - 1);
 
-        let mut selection = String::new();
-        for i in start..=end {
-            selection.push_str(lines[i]);
-            selection.push('\n');
-        }
+        let selection = if start <= end {
+            let slice = &lines[start..=end];
+            let capacity: usize = slice.iter().map(|l| l.len() + 1).sum();
+            let mut s = String::with_capacity(capacity);
+            for line in slice {
+                s.push_str(line);
+                s.push('\n');
+            }
+            s
+        } else {
+            String::new()
+        };
 
         let formatted = self.format_source(&selection);
         Ok(Some(vec![TextEdit {