That seems to be because they use whitespace as commas (look at the parameter list). It also means you can't write "a - b" as "a-b" because the whitespace is no

That seems to be because they use whitespace as commas (look at the parameter list). It also means you can't write "a - b" as "a-b" because the whitespace is now required. I can remember many times that I have typed "a-b" or "a+1" so I wouldn't be able to write in my natural style in this language. Maybe I'm wrong for using that style in the first place, but I think languages should be a little more permissive with style preferences like this.