remove hardcoded keyvals

keymap.fnl

@@ -2,19 +2,26 @@
 (local { : view } (require :fennel))
 
 (local modifier-keyvals
-       {
-        ;; These aren't canonical or official, this is just the
-        ;; result of pressing keys on my keyboard. If Gtk/Gdk/GI
-        ;; implemented KeyEvent.is_modifier we wouldn't have to
-        ;; do this
-        65507 :control_l
-        65505 :shift_l
-        269025067 :fn
-        65515 :windows
-        65513 :alt_l
-        65027 :alt_gr
-        65508 :control_r
-        })
+       ;; we need to detect and discard modifier-only key events when
+       ;; looking for the next key in a key sequence. Gtk/Gdk
+       ;; allegedly has KeyEvent.is_modifier to do this but it's always
+       ;; 0 because GI doesn't expose it.
+       (let [names
+             [
+              :Control_L
+              :Control_R
+              :Control
+              :Shift_L
+              :Shift_R
+              :WakeUp                   ; labelled "Fn"
+              :Super_L                  ; labelled with Windows logo
+              :Super_R                  ; menu key? not on my keyboard
+              :Alt_L
+              :Alt_R
+              :ISO_Level3_Shift         ; AltGr
+              ]]
+         (collect [_ n (ipairs names)]
+           (values (Gdk.keyval_from_name n) n))))
 
 (fn modifier? [keyval]
   (. modifier-keyvals keyval))
@@ -85,6 +92,9 @@
 
 
 { : recogniser
+  :keyval {
+           :Escape (Gdk.keyval_from_name "Escape")
+           }
   :_ {
       ;; symbols in _ are exported only for testing
       : keychord->spec