Elaborating on 3/4: the domain experts don't need to be compiler experts too. There are always going to be more numeric-like types (int, float, complex, bigint

Elaborating on 3/4: the domain experts don't need to be compiler experts too. There are always going to be more numeric-like types (int, float, complex, bigint, rational, symbolic-comp types etc.). Numeric vectors that act like numbers are useful (see: numpy), and trying to stick those all into the language is far harder than allowing extensibility.