Crystal is nice since they added a decent concurrency model, but it doesn't support one of the major platforms (windows)

The worst part of ruby imo is the fact that a hash can have both string and symbol keys. Countless times I have encountered issues where a function takes an options hash and the callers use both string and symbols for the same key depending on which caller it is. I end up calling the function to convert to symbols all the time.

I'm trying to think of any typical chars that don't already mean something and I think at best you'd have to use a pair and even then it would potentially break older code. Very badly offhand something like: `attr_accessor ~:String :name` and `def sing(~:Song song):` seems pretty ugly but borderline feasible on the premise that while ~ and : have meaning in Ruby, it's not super likely that bitwise inverting symbols is common. (I'm sure there more reasons that wouldn't work or isn't great.)

I don't like the separate file thing, but it does seem more challenging than I'd have thought to avoid.

I guess on a tangent Ruby code historically cares a lot more for duck typing so strong typing will be a headache for a lot of stuff.

I genuinely think that adding `:` as a hash separator was a mistake. Apart from anything else, you get this weird effect where the type of the key in `{"foo": bar}` isn't what you think it is.