A simple package implementing a DSL for generating format strings. ```(Common Lisp) (make-format-string '(:str)) #| ==> "~a" |# (make-format-string '((:map () :str))) #| ==> "~{~a~}" |# (define-message hello (name) "Hello " :str) (define-message print-comma-separated (values) (:map () :str)) ```