new-objective

<Purpose> Implement a new objective for the jolt-eval optimization framework. An objective is a measurable quantity that the AI optimizer tries to minimize — either a static analysis metric or a performance benchmark. This skill handles all the boilerplate: creating the objective struct, implementing the `Objective` trait, registering it in the appropriate enum, creating a const key, adding an `ObjectiveFunction`, creating a Criterion benchmark, and running `sync_targets.sh`. </Purpose> <Execution_Policy> - The user must provide an objective name (lowercase with underscores, e.g. `cyclomatic_complexity`). - Ask the user what is being measured and whether it's a static analysis or performance objective. - Follow existing patterns exactly — study lloc.rs (static analysis) and binding.rs (performance) as models. - Always run clippy and tests before reporting success. </Execution_Policy> <Steps> ## Phase 1: Gather Requirements 1. Validate the argument `{{ARGUMENTS}}`: must be a valid Rust identifier (lowercase alphanumeric + underscores). Reject otherwise. 2. Ask the user: - What is being measured? (becomes the `description()`) - Is this a **static analysis** objective or a **performance** objective? - Static analysis: computes a metric by analyzing source code (e.g. lines of code, complexity). Overrides `collect_measurement()`, uses `Setup = ()`. - Performance: computes a metric by running/profiling some computation (e.g. wall-clock time, max RSS). Overrides `setup()` and `run()`. - What are the units? (e.g. "lines", "s", "bugs") - What files/directories does this objective measure? (used for `diff_paths()` scoping) ## Phase 2: Explore Context 1. Read `jolt-eval/src/objective/mod.rs` to understand the current enums and dispatch methods. 2. Read `jolt-eval/src/objective/objective_fn/mod.rs` to understand objective function registration. 3. Read an existing objective for reference: - Static analysis: `jolt-eval/src/objective/code_quality/lloc.rs` - Performance: `jolt-eval/src/objective/performance/binding.rs` 4. Explore the modular crates that own the measured functionality. ## Phase 3: Implement Create the objective file following the full template for the objective kind (both in this skill's directory): - **Static analysis**: `jolt-eval/src/objective/code_quality/<objective_name>.rs` — follow `references/static-analysis.md` - **Performance**: `jolt-eval/src/objective/performance/<objective_name>.rs` — follow `references/performance.md` (includes Criterion setup/run guidelines) ## Phase 4: Register in Enums ### 4a. Add module declaration Edit the appropriate `mod.rs`: - Static analysis: `jolt-eval/src/objective/code_quality/mod.rs` — add `pub mod <objective_name>;` - Performance: `jolt-eval/src/objective/performance/mod.rs` — add `pub mod <objective_name>;` ### 4b. Add enum variant and dispatch Edit `jolt-eval/src/objective/mod.rs`: **For static analysis**, add to `StaticAnalysisObjective`: 1. New variant in the enum 2. Entry in `all()` with the `target_dir` field 3. Match arm in every dispatch method: `name()`, `description()`, `collect_measurement()`, `collect_measurement_in()`, `units()` **For performance**, add to `PerformanceObjective`: 1. New variant in the enum 2. Entry in `all()` 3. Match arm in every dispatch method: `name()`, `units()`, `description()` 4. Match arm in `diff_paths()` — return the appropriate path slice ### 4c. Add const re-export Add a `pub use` line in `jolt-eval/src/objective/mod.rs`: ```rust pub use <submodule>::<objective_name>::<UPPER_NAME>; ``` ## Phase 5: Add Objective Function Edit `jolt-eval/src/objective/objective_fn/mod.rs`: 1. Import the const key: ```rust use super::{..., <UPPER_NAME>}; ``` 2. Add a const `ObjectiveFunction`: ```rust pub const MINIMIZE_<UPPER_NAME>: ObjectiveFunction = ObjectiveFunction { name: "minimize_<objective_name>", inputs: &[<UPPER_NAME>], evaluate: |m, _| m.get(&<UPPER_NAME>).copied().unwrap_or(f64::INFINITY), }; ``` 3. Add it to `ObjectiveFunction::all()`. ## Phase 6: Create Criterion Benchmark (performance objectives only) Performance objectives are measured via Criterion — without the bench file, the optimization harness can't measure them. Create `jolt-eval/benches/<objective_name>.rs`: ```rust use jolt_eval::objective::performance::<objective_name>::<Name>Objective; jolt_eval::bench_objective!(<Name>Objective); ``` Then run `./jolt-eval/sync_targets.sh` to update `Cargo.toml` with the new `[[bench]]` entry. ## Phase 7: Validate Run these commands (all must pass): ```bash # Format cargo fmt -q # Lint cargo clippy -p jolt-eval -q --all-targets -- -D warnings # Run tests cargo nextest run -p jolt-eval --cargo-quiet # For static analysis objectives, verify the measurement works cargo run -p jolt-eval --bin measure-objectives -- --objective <objective_name> # For performance objectives, verify the benchmark compiles cargo bench -p jolt-eval --bench <objective_name> -- --test ``` If any step fails, fix the issue and re-run. </Steps> Task: Implement a new objective for jolt-eval. {{ARGUMENTS}}