WebGL's swizzling vector selectors.[1] Where v.x desugars as v[0], v.y as v[1]. Similarly for z and w. Also r,g,b,a. And they swizzle: v.rgb, v.xz, v.zx . So `v1.xy = v0.yx` reflects.
Therefore I would prefer something like this to be the usual array access syntax:
val chars = Array("a", "b", "c")
val secondChar = a.2 // as a shorthand for `chars.atIndex(2)`, or equivalently `chars.atOffset(1)`, maybe also with `a..1` for the offset case
You can write functions like xyz(v) and that works well enough. Even better if you have ufcs or methods.