Basic working mode rings

Rings are a natural structure to use for modes. This has been planned
for a long time and this is a basic working version that we can
iterate on. It replaces modes with mode rings at a particular level in
a specific tower (lisp tower, so that we can rotate normal → symex →
normal), and stays behind black box interfaces.

rigpa-mode-mode.el

@@ -30,6 +30,7 @@
 (require 'evil)
 (require 'rigpa-text-parsers)
 (require 'rigpa-meta)
+(require 'dynaring)
 
 (evil-define-state mode
   "Mode state."
@@ -150,15 +151,44 @@ to ensure, upon state transitions, that:
   "Enter mode MODE-NAME."
   (chimera-enter-mode (ht-get rigpa-modes mode-name)))
 
+(defun rigpa--rotate-mode-ring (direction)
+  "Rotate the current mode ring in DIRECTION."
+  (interactive)
+  (let* ((tower (rigpa--local-tower))
+         (tower-height (rigpa-ensemble-size tower))
+         (level-number (max (min rigpa--current-level
+                                 (1- tower-height))
+                            0))
+         (ring (rigpa-ensemble-member-at-position tower
+                                                  level-number)))
+    (funcall direction ring)
+    (rigpa-enter-mode
+     (rigpa-editing-entity-name
+      (dynaring-value ring)))))
+
+(defun rigpa-rotate-mode-ring-left ()
+  "Rotate the current mode ring to the left."
+  (interactive)
+  (rigpa--rotate-mode-ring #'dynaring-rotate-left))
+
+(defun rigpa-rotate-mode-ring-right ()
+  "Rotate the current mode ring to the right."
+  (interactive)
+  (rigpa--rotate-mode-ring #'dynaring-rotate-right))
+
 (defun rigpa--enter-level (level-number)
   "Enter level LEVEL-NUMBER"
   (let* ((tower (rigpa--local-tower))
          (tower-height (rigpa-ensemble-size tower))
          (level-number (max (min level-number
                                  (1- tower-height))
-                            0)))
-    (let ((mode-name (rigpa-editing-entity-name
-                      (rigpa-ensemble-member-at-position tower level-number))))
+                            0))
+         (level (rigpa-ensemble-member-at-position tower
+                                                   level-number))
+         (mode (if (dynaringp level)
+                   (dynaring-value level)
+                 level)))
+    (let ((mode-name (rigpa-editing-entity-name mode)))
       ;; so, we're expecting the tower to be a list containing
       ;; _modes_. Instead, we want to change it to contain
       ;; _mode rings_. Let's first convert it into a mode ring
@@ -316,7 +346,7 @@ is precisely the thing to be done."
 
 (defun rigpa-serialize-mode (mode tower level-number)
   "A string representation of a mode."
-  (let ((name (rigpa-editing-entity-name mode)))
+  (let ((name (rigpa-editing-entity-name (if (dynaringp mode) (dynaring-value mode) mode))))
     (concat "|―――"
             (number-to-string level-number)
             "―――|"

rigpa-types.el

@@ -28,6 +28,7 @@
 
 (require 'cl-lib)
 (require 'chimera)
+(require 'dynaring)
 
 (cl-defstruct editing-ensemble
   "Specification for an editing ensemble."
@@ -48,7 +49,7 @@ entity, such as modes, towers or complexes.")
 
 (defun rigpa-ensemble-member-position-by-name (ensemble name)
   "The position of a member in an ensemble, by name."
-  (seq-position (seq-map #'rigpa-editing-entity-name
+  (seq-position (seq-map (lambda (m) (rigpa-editing-entity-name (if (dynaringp m) (dynaring-value m) m)))
                          (editing-ensemble-members ensemble))
                 name))
 

rigpa.el

@@ -333,8 +333,7 @@ and simply toggles whether the menu is visible or not."
         (make-editing-ensemble :name "lisp"
                                :default "symex"
                                :members (list chimera-insert-mode
-                                              chimera-symex-mode
-                                              chimera-normal-mode)))
+                                              (dynaring chimera-normal-mode chimera-symex-mode))))
 
   ;; complexes for base editing levels
   (setq rigpa-general-complex