Macro: MATCH-CASE

Documentation

NB: the clauses wil be compiled at macro expansion time.

Source

(defmacro match-case (form &rest clauses)
  "NB: the clauses wil be compiled at macro expansion time."
  (when clauses
    (destructuring-bind ((spec &rest body) &rest other-clauses) clauses
      (with-unique-names (form-sym matched-p dummy bindings)
        (multiple-value-bind (matcher-func vars)
	    (make-matcher spec)
	  (declare (ignore matcher-func))
	  `(let ((,form-sym ,form))
	     (multiple-value-bind (,matched-p ,dummy ,bindings)
		 (match (make-matcher ',spec) ,form-sym)
	       (declare (ignore ,dummy) (ignorable ,bindings))
	       (if ,matched-p
		   (let ,vars
		     ,@(mapcar (lambda (var-name)
				 `(setf ,var-name (cdr (assoc ',var-name ,bindings))))
			       vars)
		     ,@body)
		   (match-case ,form-sym ,@other-clauses)))))))))