SE-0350 (second review): Regex Type and Overview

[Michael_Ilseman]

Yes, and it probably makes sense to appear in the up-coming "String processing algorithms" proposal.

Thanks for bringing it up! This is an unintentional omission (PR).

While this is nice to have, I believe the truly interesting and powerful use cases come with the ability to extract values from the pattern match itself, which is future work and requires language features:

@Michael_Ilseman

2. Introduce syntax for a new kind of value-binding-pattern:

let myValue: T = ...                     // something of type T
let pattern: MyTPattern<(U,U)> = ...     // something that matches a T to (U, U)
let otherPattern: OtherTPattern<V> = ... // something that matches a T to V
switch myValue {
  case (let a: Int, let b: Int) <- pattern: ... // tries `pattern`, then tries default U->Int pattern
  case let pair <- pattern: ...                 // tries `pattern`, pair has type (U,U)
  case let d: Double <- otherPattern: ...       //  tries `otherPattern`, then tries default V->Double pattern
  case let num <- otherPattern: ...             // tries `otherPattern`, num has type V
}