Hydra_Internals_11.swift

Hydra_Internals_11.swift

internal func map_parallel<A, B, S: Sequence>(context: Context, items: S, transform: @escaping (A) throws -> Promise<B>) -> Promise<[B]> where S.Iterator.Element == A {
	let transformPromise = Promise<Void>(resolved: ())
	return transformPromise.then(in: context) { (Void) -> Promise<[B]> in
		do {
			let mappedPromises: [Promise<B>] = try items.map({ item in
				return try transform(item)
			})
			return all(mappedPromises)
		} catch let error {
			return Promise<[B]>(rejected: error)
		}
	}
}