smb.clj

(defn bind-vec [state-map start-state [stroke & strokes] func force?]
  (when-not force?
    (let [old-val (get-in start-state [start-state stroke])]
      (cond
        (and (symbol? old-val) (not strokes))
          (throw (Exception. "New binding would be eclipsed by existing binding"))
        (and (not (symbol? old-var)) strokes)
          (throw (Exception. "Existing binding would eclipse new binding"))
        (and (not (symbol? old-var)) (not strokes))
          (throw (Exception. "New binding would replace existing binding")))))
  (if strokes
    (let [new-state (gensym 'state)]
      (recur (assoc-in state-map [start-state stroke] new-state)
             new-state strokes func force?))
    (assoc-in state-map [start-state stroke] func)))

; ...and then something like:

(defn register [] (alt nil [\" (append :register (alpha))]))
(defn num-arg [arg-name] (alt nil [(append arg-name (digit)) (num-arg arg-name)]))

(bind-keys :cmd [(num-arg :early-num) (register) \y
                 (alt (append :double \y) (movement) (visual-block))])