Whoops, I should've read the docs more closely. You can specify your own default values for unspecified keywords:

(define (my-func #!key (bool-arg 'unspecified)) (if (eq? bool-arg

'unspecified) "bool-arg unspecified" bool-arg))

(my-func)

"bool-arg unspecified"

(my-func bool-arg: #t)

#t

(my-func bool-arg: #f)

#f

Sorry for the spam, -- Matt

On Sun, Jun 19, 2011 at 6:28 PM, Matthew Koichi Grimes mkg@cs.nyu.eduwrote:

When a keyword argument is left unspecified, it is initialized to #f. This can get weird for optional boolean arguments. For example:

Example:

...

(define (my-func #!key bool-arg) (if bool-arg bool-arg "bool-arg

unspecified"))

...

(my-func bool-arg: #t)

#t

...

(my-func)

"bool-arg unset"

...

(my-func bool-arg: #f)

"bool-arg unset"

Is there any way to distinguish between keyword arguments that were never set, and keyword arguments that were set to #f?