Function deepCopyFrom

packages/db/src/query/optimizer.ts:854–875

(from: From)

}

function deepCopyFrom(from: From): From {
  if (from.type === `collectionRef`) {
    return new CollectionRefClass(from.collection, from.alias)
  }

  if (from.type === `queryRef`) {
    return new QueryRefClass(deepCopyQuery(from.query), from.alias)
  }

  if (from.type === `unionAll`) {
    return new UnionAllClass(
      from.queries.map((branch) => deepCopyQuery(branch)),
    )
  }

  return new UnionFromClass(
    from.sources.map(
      (source: CollectionRefClass | QueryRefClass) =>
        deepCopyFrom(source) as any,
    ),
  )
}

function deepCopyJoinFrom(
  from: CollectionRefClass | QueryRefClass,