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00:00:00 – 00:09:01
The video focuses on explaining the use and significance of the `some` keyword, also referred to as the opaque type, in Swift programming. Ravi starts by illustrating how a manufacturing company producing laptops and keyboards can represent these products in code using a protocol (`product`) with associated types to handle different product codes. He highlights the use of associated types to specify generic types for properties, showcasing the flexibility in Swift's type system.
To address issues arising from protocols with associated types that lead to compiler errors, Ravi introduces the `some` keyword. This keyword allows for the return of a single, concrete type, aiding in type encapsulation and hiding the underlying type from consumers. He further demonstrates the application of `some` through a function `squareArrayElements` that returns squared elements from an array.
The explanation extends to the use of `some` with `LazyMapSequence` and `sequence` protocols in Swift, emphasizing its elegance over returning concrete types, especially in the context of framework projects. Ravi also touches on the prevalent use of `some` in SwiftUI, such as with `some View`. The video concludes with an encouragement for viewers to share their experiences, utilize provided resources, and support the channel.
00:00:00
In this part of the video, Ravi introduces the concept of the ‘some’ keyword, also known as the opaque type, using a manufacturing company example that produces two products: laptops and keyboards. He explains how to represent this in code by creating a ‘product’ protocol with a function for product description, and two structures, ‘laptop’ and ‘keyboard’, inheriting from this protocol. Each product has a unique product code: laptops have a string code and keyboards have an integer code. Ravi demonstrates how to use an Associated type to handle the different types of product codes within the protocol. He outlines that the protocol will define a generic ‘code’ type for the product code property, which can then be specified as string or integer in the laptop and keyboard structures. This example also marks the first instance of him explaining the Associated type on his channel, highlighting its use case in projects.
00:03:00
In this segment, the speaker is demonstrating the process of creating a function for a factory to manufacture two products, which in this scenario are a laptop and a keyboard. The function, named `makeProducts`, intends to return a product. However, the Swift compiler presents an error due to the protocol `product` having an associated type requirement, resulting in multiple implementations. To address this issue, the speaker explains the necessity of returning a concrete type using the `some` keyword, effectively resolving the error by specifying that only one concrete type (e.g., a laptop with a specific product code) is being returned.
Furthermore, for a real-world scenario, the speaker suggests that it would be more straightforward to directly return the respective concrete type (laptop or keyboard) instead of using such keyword.
The segment then transitions into an explanation on the actual use of the `some` keyword, which is for encapsulation, hiding the concrete type from the real world. As an illustrative example, the speaker introduces a function called `squareArrayElements`, which takes a generic numeric parameter and returns a sequence of squared elements from the array.
00:06:00
In this part of the video, the speaker explains how to use the `some` keyword in Swift, specifically with the `LazyMapSequence` and `sequence` protocols. They describe how returning a protocol type using `some` can be more elegant than returning a concrete type, highlighting its utility in framework projects. The speaker switches to a SwiftUI project to demonstrate another example where `some` is commonly used, such as with `some View`. They also invite viewers to share their own experiences using the `some` keyword and provide resources in the video description, including code examples available on GitHub and Google Drive. The segment concludes with a request for viewers to support the channel by subscribing and sharing the content.