gepa-spo/dist/budget.js

Genetic-Pareto prompt optimizer to evolve system prompts from a few rollouts with modular support and intelligent crossover

/**
 * Lightweight budget tracker to enforce and introspect token/call budgets.
 *
 * When disabled, all methods are no-ops and `remaining()` always returns the
 * initial start value provided to the constructor. This allows safe wiring
 * into existing call sites without changing behavior.
 */
export class BudgetTracker {
    start;
    enabled;
    remainingInternal;
    /**
     * Create a new tracker.
     *
     * @param start - Initial remaining budget (non-negative integer)
     * @param enabled - Whether tracking is active. If false, all operations are no-ops.
     */
    constructor(start, enabled) {
        const safeStart = Number.isFinite(start) && start >= 0 ? Math.floor(start) : 0;
        this.start = safeStart;
        this.enabled = Boolean(enabled);
        this.remainingInternal = safeStart;
    }
    /** Current remaining budget. When disabled, returns the initial `start` value. */
    remaining() {
        return this.enabled ? this.remainingInternal : this.start;
    }
    /**
     * Decrease the budget by `n` (defaults to 1). Negative values are ignored.
     * When disabled, this is a no-op.
     *
     * @param n - Amount to decrement (defaults to 1)
     * @param _tag - Optional tag for future attribution (ignored in noop scaffold)
     */
    dec(n = 1, _tag) {
        if (!this.enabled)
            return;
        const amt = Number.isFinite(n) && n > 0 ? Math.floor(n) : 0;
        if (amt === 0)
            return;
        this.remainingInternal = Math.max(0, this.remainingInternal - amt);
    }
    /** Whether there is at least `n` budget remaining. Always true when disabled. */
    canAfford(n) {
        if (!this.enabled)
            return true;
        const amt = Number.isFinite(n) && n > 0 ? Math.floor(n) : 0;
        return this.remainingInternal >= amt;
    }
}
export default BudgetTracker;