[swift-evolution] [Pitch] Extending Swift Literals

[Erica Sadun]

> On Jul 10, 2016, at 10:30 PM, Xiaodi Wu <xiaodi.wu at gmail.com> wrote:
> 
> Questions/comments--
> 
> What's your use case for these?
> 
> For proposed literals like `point`, I'm having trouble visualizing how that could be literally represented. Since the difference between one point and another is its coordinate, would we just see a point floating on the screen?
> 
> Something like `size` seems ill-suited for literal representation, as opposed to a shape (e.g. rectangle). Why is it a two-dimensional size anyway? Also, since literals have no type, is there any scenario in which a `size` literal of a certain width and height and a `point` literal with a certain x and y coordinate are meaningfully different?
> 
> Finally, several of these look like string literals with types. For instance, `unicode` seems to reflect a desire to refer to characters by their official names. Perhaps that could be proposed instead as a new escaping syntax for strings? Something like `let string = "\u{{DOG FACE}}"` might be pretty handy.

It doesn't have to be "represented". It can be used as `#literal.point(x: 3.5, y: 2.0)` without any "pretty" picture.

A literal offers a typeless universal value that can be interpreted by a conforming type as a representation of itself, so you can have:

let x: CGPoint = #literal.point(x: 3.5, y: 2.0)
let x: NSPoint = #literal.point(x: 3.5, y: 2.0)
let x: float2 = #literal.point(x: 3.5, y: 2.0)

-- E