cl-schedule: A scheduling library in CL

A task scheduler library for lisp. It's forked from Gabor Melis's Clon which can be found at http://quotenil.com/clon/clon-latest.tar.gz. This was forked near 2014 with some bug-fix.

It's then forked again by Jin-Cheng Guu in mid 2021 into his repo, aiming to replace traditional cron managers. It provides more examples, documents and features. In particular, in an example below we show how to make a schedule that does what a traditional cron manager would do for the control string

*/25 5-6,10 * 7 1-2

Long story short, it can be expressed as the following.

(make-typed-cron-schedule

:minute '(satisfies twenty-five-p)

:hour '(or (integer 5 6) (member 10))

:month 7

:day-of-week '(integer 0 1))