I admit my hastily written example is clumsy, but the general idea still holds in your rendering of it. Nesting with commas is just as confusing as nesting wit

I admit my hastily written example is clumsy, but the general idea still holds in your rendering of it. Nesting with commas is just as confusing as nesting with parenthesis. It forces your reader to operate with more than one contexts at a time, and this is exactly what pushes up the complexity level. Even in Lisp, I realised that I always tend to build flat DSLs instead of the nested, using the non-parenthesised punctuation wherever possible. And I am not alone, take a look at the LOOP macro for example.