Mastering OptionSet in Swift

Simplifying Complex Sets of Options

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OptionSet is a protocol that allows developers to represent a set of options in a type-safe way.

It might be used for representing combinations of values in scenarios where multiple options might apply simultaneously.

This article dives into what OptionSet is, how to use it, and examples of how it can simplify complex code involving sets of options.

What is OptionSet?

A protocol that allows you to define a set of unique, discrete options that can be combined efficiently using bitwise operations.

It is commonly used to represent configurations, permissions or status indicators where multiple values might be needed at once.

What Use OptionSet?

OptionSet is potentially superiour to using multiple Bool flags as it is likely to provide clean code that is easy to read, maintain and build features on.

OptionSet is advantageous in scenarios where:

• There are multiple options that can apply simultaneously
• Managing multiple Boolean properties is too complex
• Memory efficiency is important

Creating an OptionSet

struct TextStyleOptions: OptionSet {
    let rawValue: Int
    static let bold = TextStyleOptions(rawValue: 1 << 0)
    static let italic = TextStyleOptions(rawValue: 1 << 1)
    static let underline = TextStyleOptions(rawValue: 1 << 2)
    static let strikethrough = TextStyleOptions(rawValue: 1 << 3)
}

Option sets all conform to RawRepresentable by inheritance using the OptionSet protocol. Whether using an option set or creating your own, you use the raw value of an option set instance to store the instance’s bitfield. The raw value must therefore be of a type that conforms to the FixedWidthInteger protocol, such as UInt8 or Int.

In this case rawValue is an Int.

.bold has a rawValue of 1 (binary 0001).

.italic has a rawValue of 2 (binary 0010).

.underline has a rawValue of 4 (binary 0100).