Why do some attributes start with '@' while others done't?

[Ola Fosheim Grøstad via Digitalmars-d]

On Friday, 22 January 2016 at 15:34:18 UTC, Wyatt wrote:
> "Contemporary". ;)

Well, contemporary in the sense that next generation of 
programmers are exposed to it and conditioned to it. So if you 
pick up the common syntactical structures from those languages it 
feels immediately natural to more people from the upcoming 
generation.

> Aside from Swift's optional semicolons, they're really not all 
> that different.

Here's one big difference that matters a lot for legibility: 
"name: type". Consistent usage of sigils matters a lot of both 
readability, autocompleting and error messages.

> Like Swift, C#, Javascript, Go, Haxe, Rust, Dart, et al?  
> Really, people have been predicting the death of curly-braces 
> languages for decades now, and they're as strong as ever.

Did I say anything about curly braces? A new language now should 
be designed with IDE autocompletion in mind and graphical 
oriented editing.

> Do you have anything to base this on, or is it just what you'd 
> (apparently) like to see?

What?

I'm arguing if favour of sticking to what is emerging as the 
common idioms that lead to familiarity. Then I argue in favour of 
consistency, autocompletion-friendliness and higher levels of 
legibility.

High levels of usability is very hard to achieve. One cannot 
arrive at excellent usability by adding and adding and adding... 
You need to redesign, test, evaluate, redesign, test, evaluate... 
etc.