Function rollup

rollup<T>(items: readonly T[], options: RollupOptions<T>): RollupEntry<T>[]
Aggregates a flat dataset into one RollupEntry per distinct key.
Type Parameters
- T
Parameters
- items: readonly T[]
  The dataset to aggregate.
- options: RollupOptions<T>
  RollupOptions describing how to group and sum.
Returns RollupEntry<T>[]
One entry per distinct grouping key, in first-seen order.
Example
```
const byCustomer = rollup(invoices, {
  by: 'customer',
  value: 'revenue',
  metrics: { cost: 'cost' },
});
```
- Defined in rollup/index.ts:78