traditional-let-macro.lisp

(defmacro my-let(binds &body body)
  `((lambda,(mapcar #'ensure-car binds)
      ,@body)
    ,@(mapcar #'init-form binds)))

(defun ensure-car (arg)
  (if(listp arg)
    (car arg)
    arg))

(defun init-form (arg)
  (if(listp arg)
    (cadr arg)
    nil))

(defmacro my-let*(binds &body body)
  (labels((rec(binds)
            (if(endp binds)
              body
              (body(car binds)(cdr binds))))
          (body(bind rest)
            `(((lambda(,(ensure-car bind))
                ,@(rec rest))
              ,(init-form bind)))))
    (car(rec binds))))