(in-package #:let-over-lambda)


(eval-when (:compile-toplevel :load-toplevel :execute)
  (defun make-defmacro (name lambda-list docstring declarations body)
    (append (list 'defmacro name lambda-list )
            (when docstring (list docstring))
            declarations
            body))
  (defun make-let (bindings body)
    (list* 'let bindings body)))


(defmacro defmacro/g! (name args &rest body)
  (let ((syms (remove-duplicates
               (remove-if-not #'g!-symbol-p
                              (flatten body)))))
    (multiple-value-bind (body declarations docstring)
        (parse-body body :documentation t)
      (make-defmacro name args docstring declarations
                     (list (make-let (mapcar
                                      (lambda (s)
                                        (list s (list 'gensym (subseq (symbol-name s) 2))))
                                      syms)
                                     body))))))

(macroexpand-1 '(defmacro/g! moo (a) (list 'list (list 'quote a) (list 'quote a))))
--> (defmacro moo (a) (let nil (list 'list (list 'quote a) (list 'quote a))))
    t