https://github.com/Shinmera/lambda-fiddle.git
git clone 'https://github.com/Shinmera/lambda-fiddle.git'
(ql:quickload :lambda-fiddle)
Lambda-fiddle is a collection of utilities to process lambda-lists. Mostly useful in contexts where you want a macro that uses lambda-lists in some fashion but need more precise processing.
Included are –for each standard lambda-list part– a remove-*-part and *-lambda-var/s function that remove the specified part or extract the associated variable/s, respectively. These are all based on the more generale collect-for-keyword and exclude-for-keyword functions that will scan the given lambda-list for the keyword and collect accordingly. The generalised functions may also be useful if you plan to include your own non-standard keywords.
(lambda-fiddle:remove-aux-part '(foo bar &key baz &aux (something else) altogether))
(lambda-fiddle:aux-lambda-vars '(foo bar &key baz &aux (something else) altogether))
Additionally, there is split-lambda-list and its macro partner with-destructured-lambda-list that split the lambda-list into all its parts and return/bind them accordingly, allowing for easy access.
(lambda-fiddle:split-lambda-list '(&whole wide world &key roles))
(lambda-fiddle:with-destructured-lambda-list (:required req) '(foo bar &optional baz)
req)