⚡ Bolt: Optimize Display implementation for Value by removing heap allocations

[ashyanSpada]

💡 What: Optimized the fmt::Display implementation for the Value enum in src/value.rs by removing unnecessary .clone() calls and intermediate String allocations (e.g., String::from, format!(), and push_str()).
🎯 Why: Writing directly to the Formatter using write! significantly reduces memory allocation and copying overhead, leading to faster string formatting operations for AST evaluation and display.
📊 Impact: Eliminates several heap allocations and string copies per formatted list or map value, improving overall formatting performance.
🔬 Measurement: Verified through cargo test and cargo bench, which show no regressions in behavior and maintain exact output formatting.

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PR created automatically by Jules for task 14944960043651433426 started by @ashyanSpada

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.55%. Comparing base (9a4a6cc) to head (6022f8f).

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #52   +/-   ##
=======================================
  Coverage   89.55%   89.55%           
=======================================
  Files          11       11           
  Lines        1063     1063           
=======================================
  Hits          952      952           
  Misses        111      111           

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[gemini-code-assist]

Code Review

This pull request refactors the Display implementation for the Value enum, improving efficiency by removing redundant clones and replacing manual string concatenation with direct writes to the formatter. The review feedback identifies opportunities to improve the output formatting of lists and maps by eliminating trailing separators.

[gemini-code-assist]

The current implementation results in a trailing comma for non-empty lists (e.g., [1,2,3,]). While the PR aims to maintain parity with the previous implementation, this is a good opportunity to improve the output formatting by removing the trailing separator for a more standard representation.

Suggested change

	write!(f, "value list: [")?;
	for value in values {
	s.push_str(format!("{},", value.clone()).as_str());
	write!(f, "{},", value)?;
	}
	s.push_str("]");
	write!(f, "value list: {}", s)
	write!(f, "]")
	write!(f, "value list: [")?;
	for (i, value) in values.iter().enumerate() {
	if i > 0 {
	write!(f, ",")?;
	}
	write!(f, "{}", value)?;
	}
	write!(f, "]")

[gemini-code-assist]

Similar to the list implementation, the map formatting includes a trailing semicolon and space (e.g., {key: k,value: v; }). Consider refactoring the loop to avoid the trailing separator and ensure a cleaner, more consistent output format.

                write!(f, "value map: {{")?;
                for (i, (k, v)) in m.iter().enumerate() {
                    if i > 0 {
                        write!(f, " ")?;
                    }
                    write!(f, "key: {},value: {};", k, v)?;
                }
                write!(f, "}}")

[Copilot]

Pull request overview

Optimizes the fmt::Display implementation for the Value enum by removing unnecessary cloning and avoiding intermediate String allocations during formatting.

Changes:

• Removes redundant .clone() calls when formatting scalar Value variants.
• Reworks List and Map formatting to write directly into the fmt::Formatter instead of building intermediate strings.

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[Copilot]

The Display output for Value::List/Value::Map is now built via multiple write! calls. Since this is user-visible formatting and can be easy to accidentally change (e.g., trailing commas, braces, separators), please add a unit test that asserts the exact to_string() output for a few representative values (including empty/non-empty list and map) to prevent regressions during future refactors.