[parenscript-devel] lisp-like lambda lists (keyword, option, and rest arguments)

[Red Daly]

My changes are now synced up with the repository.  Feel free to play 
around with the latest and greatest.

You might notice that the function toArray() is not defined, required 
for &rest processing.  toArray is simply..

(defun to-array (array-like)
    (let ((result (array)))
       (dotimes (i array-like.length)
         (setf (aref array i) (aref array-like i)))))

-Red

Vladimir Sedach wrote:
> 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 at 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
>>
>>
>>
>>
>> _______________________________________________
>> parenscript-devel mailing list
>> parenscript-devel at common-lisp.net
>> http://common-lisp.net/cgi-bin/mailman/listinfo/parenscript-devel
>>
>>     
> _______________________________________________
> parenscript-devel mailing list
> parenscript-devel at common-lisp.net
> http://common-lisp.net/cgi-bin/mailman/listinfo/parenscript-devel
>