Function batch_eval_parallel 

pub fn batch_eval_parallel(
    func: CompiledExprFn,
    var_sets: &[f64],
    num_vars: usize,
    results: &mut [f64],
    chunk_size: usize,
) -> Result<(), BatchError>

Parallel variant of batch_eval that splits rows into chunks and evaluates each chunk on a separate fiber from the dtact runtime pool.

chunk_size controls how many rows each fiber processes. A chunk_size of 0 or a total row count ≤ chunk_size falls back to serial batch_eval.

Errors

Returns BatchError::LengthMismatch when var_sets.len() != results.len() * num_vars or chunk_size == 0 and the non-JIT stub is active.