Hi Red,
That looks awesome. I gave a though to adding something like this, but as usual I assumed it would be hard and involve hacks. You proved me wrong; I really like your implementation. Is there any effect on plain-vanilla lambda lists? If not, then I say go ahead and push it.
Vladimir
On 7/30/07, Red Daly reddaly@stanford.edu wrote:
In my local version I have added support for very Lispy lambda lists with keyword, optional, and &rest arguments. Is this a feature we should add to the language?
The Javascript convention for passing named arguments is to have an options variable that functions as a hash table for keywords. I use this convention for passing keyword arguments in Parenscript. Also, when a quoted symbol (e.g. a keyword) is found in a function call, the an options object is constructed.
Here are a few examples
(defun name (first last &key (prefix "Ms.") (middle "")) (return (+ prefix " " first " " middle " " last))) => function name (first last options) { options.prefix = options.prefix === undefined ? "Ms." : options.prefix; options.middle = options.middle === undefined ? " " : options.middle; return prefix + " " + first " " + middle + " " + last; }
(defun vote (&optional (times 1)) ...) => function vote (times) { times = times === undefined ? 1 : times; ...}
(defun append (&rest lists) ...) => function append() { lists = arguments.slice(0); ...}
(name "John" "Cunningham" :prefix "Mr." :middle "Appleton") => name("John", "Cunningham", { prefix : "Mr." , middle : "Appleton" })
I like having the extra lambda list features available in my own code. Should we add this to Parenscript?
-Red
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