dynamic-hydra-example.el

  (defvar hydra-map-of-major-modes nil)

  (defun concat-syms (&rest syms)
    (intern (apply #'concat (mapcar #'symbol-name syms))))

  (defvar hydra-leader-key "¡")
  (defvar hydra-map-of-minor-modes nil)

  (defun add-hydra-minor (mode name key hydra)
     (let*  ((hydra-body (concat-syms hydra `/body))
             (mode-map (symbol-value (concat-syms mode `-map)))
             (key-chord (concat hydra-leader-key key))
             )
       (progn
         (key-chord-define mode-map key-chord hydra-body)
         (setq hydra-map-of-minor-modes
               (plist-put hydra-map-of-minor-modes mode
                          `(name ,name key ,key action ,hydra-body))))))

  (eval-after-load "flycheck" (progn (add-hydra-minor 'flycheck-mode "Flycheck"   "f" 'hydra-error))) 
  (eval-after-load "projectile" (progn (add-hydra-minor 'projectile-mode "Projectile" "p" 'hydra-projectile)))

  (defun build-minor-modes-master-hydra () (interactive) 
         (let* ((active (-non-nil (--map (plist-get hydra-map-of-minor-modes it) (active-minor-modes) )))
                (mms (--map `(,(plist-get it 'key) ,(plist-get it 'action) ,(plist-get it 'name)) active)))
         (eval `(defhydra minor-modes-master-hydra () "Active Minor Modes"
                           ,@mms
                           ("q" nil "quit")))))

  (defun run-minor-modes-hydra () (interactive) (and (build-minor-modes-master-hydra) (minor-modes-master-hydra/body)))