Regex literals in Swift

See: Meet Swift Regex WWDC22

Swift Regex literal are compatible with Python, Perl and many others.

// Regex literals
let digits = /\d+/
// digits: Regex<Substring>

Syntax for Regex literals

Each language has its own “flavor” for (literal) regex syntax.

The Swift implementation is closely related to ICU (see ICU documentation).

• Swift Regex literals start and end with /
• Strongly typed capturing groups
  • literals infer the strong types for all the internal captures

Extended Delimiters

Syntax:

• starts with #/ and ends with /#
• See: Meet Swift Regex WWDC22 at 10:45
• See: WWDC22 Swift Regex: Beyond the Basics at 8:40

When using extended delimiters:

• slashes do not need to be escaped
• allows non-semantic whitespaces:
  • whitespace is ignored
• below date is a named capture

let regex = #/
	(?‹date>         \d｛2｝ / \d｛2｝/ \d｛4）
	(?<middle>       \P{currencySymbol}+)
	(?‹currency>     \p{currencySymbol})
/#
// Regex<(Substring, date: Substring, middle: Substring, currency: Substring)>