Parsing String parameter in path.

[sean-howard]

Hey!

Thanks for putting together this library, I'm keen to start using it straight away! However I've hit a roadblock that I've been not been able to resolve whilst digging through the documentation.

In your example scenario if the enum argument is an alphanumeric String rather than Int which Parse printer would I use in the path?

enum AppRoute {
  case buyBook(id: String)
}

let appRouter = OneOf {

  // GET /books/:id/buy
  Route(.case(AppRoute.buyBook(id:))) {
    Path { "books"; /* Parse printer??? */ "buy" }
  }
}

I've attempted to use CharacterSet from this documentation but I'm repeatedly getting compiler errors. Are you able to advise the correct one to use?

Thanks!

[stephencelis]

@sean-howard You can use Parse(.string) to peel off an entire path component:

Route(.case(AppRoute.buyBook(id:))) {
  Path { "books"; Parse(.string); "buy" }
}

And if you use a RawRepresentable type-safe wrapper for the ID, you can use .string.representing(BookId.self):

struct BookId: RawRepresentable {
  var rawValue: String
}

enum AppRoute {
  case buyBook(id: BookId)
}

let appRouter = OneOf {

  // GET /books/:id/buy
  Route(.case(AppRoute.buyBook(id:))) {
    Path { "books"; Parse(.string.representing(BookId.self); "buy" }
  }
}

[davdroman]

Is Parse(.string) equivalent to String.parser()? 🤔

[stephencelis]

@davdroman We try to make sure all .parser() types are incremental parsers, so there is no String.parser() (though we briefly had one defined on a branch if it sounds familiar).

We have a dedicated parser for consuming the rest of a string, which is the Rest parser, so Parse(.string) in this case is most equivalent to:

Rest().map(.string)

[sean-howard]

Thanks for your speedy response on this @stephencelis! Works perfectly 🤌