Understanding the basic building blocks in Swift

Swift Sequences

Anatomy of the Sequence protocol

Navdeep Singh
Oct 7, 2019 · 4 min read

A sequence is a list of values that you can step through one at a time.

Sequence Protocol and conformance

Sequences provide sequential, iterated access to its elements.

Sequences return a set of values one at a time, and those values can be “used/consumed” making revisiting those values optional.

Console: Prints 3 “Hi”

Addressing boilerplate code

func sequence<T>(first: T, next: @escaping (T) -> T?) -> UnfoldFirstSequence<T>
typealias UnfoldFirstSequence<T> = UnfoldSequence<T, (T?, Bool)>
Reduced the code by half to create a Sequence.

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Navdeep Singh

Written by

Author of Reactive programming with Swift, Senior Software Engineer — Exploring possibilities with new Tech.

The Startup

Get smarter at building your thing. Follow to join The Startup’s +8 million monthly readers & +794K followers.

Navdeep Singh

Written by

Author of Reactive programming with Swift, Senior Software Engineer — Exploring possibilities with new Tech.

The Startup

Get smarter at building your thing. Follow to join The Startup’s +8 million monthly readers & +794K followers.

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