Use structs for fkeys, allow short emacs-style key specs

- Instead of verbose keyword names like :key-ctrl-alt-arrow-left,
  store function keys as structs where modifiers crtl, alt and shift
  are slots.
- Some keys like :key-arrow-left can thus be renamed back to their
  previous short names like :left.
- Add functions to parse emacs-style key specs and key chains to
  characters and key structs:
- This allows emacs-style, compact key descriptions like
  C-M-S-<left>, that now can be used with bind for key bindings.
- define-keymap can also use structs for modified function keys
  but cant yet bind key chains.
- Adapt event-case to switch on key-name in case of key events.
- Add equalp as the test function to all assoc calls where key
  structs are used.
- Adapt functions that assumed that function keys are keywords to
  assume they are structs.
- Rename all mouse events from past for to infinitive, e.g. from
  :button-1-clicked to :button-1-click.
- Remove the modifiers flot from mouse-event because modifiers
  are now encoded in the event-key struct.
- Add method key-to-string for key structs.
- Add code-key and key-code, equivalent of cl:char-code and
  cl:code-char, to translate between key structs and ncurses codes.
- Add internal function get-key-event to check if the event is
  :mouse and to make the event object accordingly, which is then
  used for both get-event and get-wide-event.
- Fix wrap to handle long words at the end of a line.
- Fix element keymap definitions. An empty list for missing parent
  keymaps has to be explicitely given, like in defclass.

CHANGELOG.org

@@ -4,6 +4,44 @@
 
 Notable changes since v0.2 (231014), which corresponds to Quicklisp release 231021:
 
+*** Use structs for fkeys, allow short emacs-style key specs (240317)
+
+- Instead of verbose keyword names like =:key-ctrl-alt-arrow-left=,
+  store function keys as structs where modifiers crtl, alt and shift
+  are slots.
+- Some keys like :key-arrow-left can thus be renamed back to their
+  previous short names like :left.
+- Add functions to parse emacs-style key specs and key chains to
+  characters and key structs:
+
+#+BEGIN_EXAMPLE
+CL-USER> (parse-key "C-x M-c C-M-S-<home>")
+(#\Can #\Esc #\c #S(KEY :NAME :HOME :CTRL T :ALT T :SHIFT T))
+#+END_EXAMPLE
+
+- This allows emacs-style, compact key descriptions like
+  =C-M-S-<left>=, that now can be used with bind for key bindings.
+- =define-keymap= can also use structs for modified function keys
+  but cant yet bind key chains.
+- Adapt event-case to switch on key-name in case of key events.
+- Add equalp as the test function to all assoc calls where key
+  structs are used.
+- Adapt functions that assumed that function keys are keywords to
+  assume they are structs.
+- Rename all mouse events from past for to infinitive, e.g. from
+  =:button-1-clicked= to =:button-1-click.=
+- Remove the modifiers flot from mouse-event because modifiers
+  are now encoded in the event-key struct.
+- Add method =key-to-string= for key structs.
+- Add =code-key= and =key-code=, equivalent of cl:char-code and
+  cl:code-char, to translate between key structs and ncurses codes.
+- Add internal function =get-key-event= to check if the event is
+  :mouse and to make the event object accordingly, which is then 
+  used for both get-event and get-wide-event.
+- Fix wrap to handle long words at the end of a line.
+- Fix element keymap definitions. An empty list for missing parent
+  keymaps has to be explicitely given, like in defclass.
+
 *** Add extended function keys to the list of recognized events (240127)
 
 - After initializing the screen, check whether common extended

src/classes.lisp

@@ -37,13 +37,39 @@ component +--> widget ---+--> window  +--> screen
           +--> form --------> form-window
 |#
 
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (defstruct key
+    "Stuct representing a function key or a mouse button with modifier keys.
+
+A key struct is associated with an escape sequence which is parsed by ncurses
+and returned from getch or get_wch as an integer code.
+
+Every combination of a key name and the modifiers is represented by a separate
+code.
+
+Supported modifiers are ctrl (C), alt (M) and shift (S).
+
+In bindings, emacs notation is used to specify the keys which are then parsed
+to structs, for example C-S-M-<left>, C-<button-1-click>.
+
+Also see: `bind'."
+    (name  nil :type keyword)
+    (ctrl  nil :type boolean)
+    (alt   nil :type boolean)
+    (shift nil :type boolean))
+
+  ;; load this during compile time so we can read structs.
+  (defmethod make-load-form ((key key) &optional env)
+    (declare (ignore env))
+    (make-load-form-saving-slots key)))
+
 (defclass event ()
   ((key
     :initarg       :key
     :initform      nil
     :reader        event-key
-    :type          (or null integer keyword character)
-    :documentation "Character or keyword representing a function key, terminal :resize or mouse event.")
+    :type          (or null integer keyword character key)
+    :documentation "Lisp character representing a character key or key struct representing a function key or mouse button.")
 
    (code
     :initarg       :code
@@ -52,7 +78,7 @@ component +--> widget ---+--> window  +--> screen
     :type          (or null integer)
     :documentation "Integer code representing the character or function key as returned by ncurses:getch or get_wch."))
 
-  (:documentation  ""))
+  (:documentation  "And event represents characters, function keys, mouse buttons and terminal resize events."))
 
 (defclass mouse-event (event)
   ((position-y
@@ -65,14 +91,7 @@ component +--> widget ---+--> window  +--> screen
     :initarg       :x
     :initform      nil
     :type          (or null integer)
-    :documentation "The x coordinate (column) of the mouse event.")
-
-   (modifiers
-    :initarg       :modifiers
-    :initform      nil
-    :reader        event-modifiers
-    :type          (or null cons)
-    :documentation "A list containing any combination of :ctrl, :shift and :alt"))
+    :documentation "The x coordinate (column) of the mouse event."))
 
   (:documentation  "The class represents the ncurses MEVENT struct as returned by getmouse."))