Can't he write a macro that unfolds into a type specification, at least for his uses?
On Mar 29, 2010, at 9:44 AM, Sam Tobin-Hochstadt wrote:
On Mon, Mar 29, 2010 at 9:31 AM, Noel Welsh <noelwe...@gmail.com> wrote:This common pattern (define (foo a [b 1] [c 2] [d 3]) ...) which expands into a case-lambda like (define foo (case-lambda (([a] (foo a 1 2 3)) ([a b] (foo a b 2 3)) ...)) is a damn pain to type and Type in Typed Scheme. It would be really nice it one could just write: (: foo (Integer [Integer] [Integer] [Integer] -> Integer)) (define (foo a [b 1] [c 2] [d 3]) ...) in Typed Scheme.Wouldn't it though ... Really, there are two separate issues here - a convenient syntax for types with optional arguments, and support for defining functions with optional arguments. The first is less of a pain, but probably something I could implement pretty easily. Unfortunately, the second is significantly harder, because the expansion of such definitions is quite convoluted. As a short-term work-around, you can use `opt-lambda' from `mzlib/etc', whose expansion is much simpler. -- sam th sa...@ccs.neu.edu _________________________________________________ For list-related administrative tasks: http://list.cs.brown.edu/mailman/listinfo/plt-dev
_________________________________________________ For list-related administrative tasks: http://list.cs.brown.edu/mailman/listinfo/plt-dev
