On Fri, 8 Feb 2008, Wolfgang Jeltsch wrote:
Am Donnerstag, 7. Februar 2008 16:31 schrieben Sie:
Even if () would be preferred from the programmers point of view (I'm not sure how much we could reduce the number of instances though), it makes the representation less attractive on the user-side. Anyone using the library would find it annoying and would wonder why is it neccessary.
I wouldn’t wonder. Leaving out the () :* part just works because our type-level “values” are not typed, i.e., there aren’t different kinds Digit and Number but only kind *. If :+ would be a data constructor (on the value level), it would take a number and a digit argument which would forbid using a digit as its left argument. So I consider using a digit on the left as “unclean”. It’s similar to using a number as the second part of a cons cell in LISP.
seconded