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. On Sun, Jul 10, 2016 at 10:48 PM, Erica Sadun via swift-evolution < swift-evolution@swift.org> wrote: > This is purely additive and would not be eligible for Swift 3. > gist: https://gist.github.com/erica/c92f6ab115af89d5c4b9161487df6a3c > > -- E > > Extending Swift Literals > > - Proposal: TBD > - Author: Erica Sadun <http://github.com/erica> > - Status: TBD > - Review manager: TBD > > > <https://gist.github.com/erica/c92f6ab115af89d5c4b9161487df6a3c#introduction> > Introduction > > This proposal expands Swift's language literals to include common > cross-platform concepts that need not require. > <https://gist.github.com/erica/c92f6ab115af89d5c4b9161487df6a3c#motivation> > Motivation > > A Swift literal represents a fixed value in source code. A literal can be > a string, a number (for example an integer), a compound value (such as an > array), or one of several predefined "playground" literals including > colors, resource file paths, and resource images. > > Swift literals do not have types. They are universal representations that > are evaluated and their types inferred from the context in which they are > used. Because their nature is typeless, the same color literal can > initialize UIColor, NSColor, and SKColor instances. The type cannot be > inferred from the source without the context of its destination. > > let color = #colorLiteral(red: 0.8100712299, green: 0.1511939615, blue: > 0.4035313427, alpha: 1) > > > <https://gist.github.com/erica/c92f6ab115af89d5c4b9161487df6a3c#detailed-design>Detailed > Design > *Namespace redesign* > KindLiteralParameters > Color `#literal.color(red:, green:, blue:, alpha:)` floating point values > Image `#literal.image(resourceName:)` String with resource name > File `#literal.file(resourceName:)` String with resource name > *General* > KindLiteralParameters > Sound `#literal.audio(resourceName:)` String with resource name > URL `#literal.url(string:)`, `#literal.url(filePath:)` String with > resource location > Font `#literal.font(face:, size:)` string, floating point > Date `#literal.date(timeInterval:)` floating point offset from Unix epoch > Unicode `#literal.unicode(name:)` Official unicode name, e.g. > `#literal.unicode(name:"DOG FACE")` > *Geometry* > KindLiteralParameters > Point `#literal.point(x:, y:)`, `#literal.point(x:, y:, z:)`, > `#literal.point(x:, y:, z:, w:)` floating point values > Vector `#literal.vector(dx:, dy:)`, `#literal.vector(dx:, dy:, dz:)`, > `#literal.vector(dx:, dy:, dz:, dw:)` floating point > Size `#literal.size(width:, height:)`, `#literal.size(width:, height:, > depth:)` floating point > Rect `#literal.rect(x:, y:, width:, height:)` floating point > Affine Transform `#literal.affineTransform(a:,b:,c:,d:,tx:,ty:)`, > `#literal.affineTransform(translateX:, translateY:)`, > `#literal.affineTransform(scaleY:, scaleY:)`, > `#literal.affineTransform(rotation:)`, floating point > Bezier Path `#literal.bezier("M92.21,24.29H75L73,17a8.32,8.32, > 0,0,0-8.27-6.74H34.55A7.69,7.69,0,0,0,27,16.6l-2.08 4z")` String with SVG > path notation > <https://gist.github.com/erica/c92f6ab115af89d5c4b9161487df6a3c#not-included>Not > included: > > Attributed Strings: I would like to see a way to define attributed > strings (using some system like CSS/HTML) but could not think up a simple > representation similar to the others mentioned in the preceding table. > > JSON Literals: Again, probably too complex and possibly not worth their > weight. If they could exist, they'd have to be imported via a resource or > URL and transformed to a local type. > > <https://gist.github.com/erica/c92f6ab115af89d5c4b9161487df6a3c#impact-on-existing-code>Impact > on Existing Code > > This proposal is purely additive. > > <https://gist.github.com/erica/c92f6ab115af89d5c4b9161487df6a3c#alternatives-considered>Alternatives > Considered > Using distinct literal names without subsuming them into a namespaced > umbrella. > > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution > >
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