I was intrigued by that language because of the nice concepr, and then I read their Arrays reference. Arrays are written with { } and no commas between elements

I was intrigued by that language because of the nice concepr, and then I read their Arrays reference. Arrays are written with { } and no commas between elements. I have the feeling the common assumption for arrays is [ ] think python, java, php, javascript, haskell,... Why would someone do that ?