shithub: puzzles

Download patch

ref: 418cb3a5671404d2d91bf221887df2be2ae2654f
parent: e411db788cfc0d0ed54b3c9b9deb15edba7d237a
author: Ben Harris <bjh21@bjh21.me.uk>
date: Mon Feb 13 17:41:40 EST 2023 

Make encode_ui() and decode_ui() optional in back-ends

The majority of back-ends define encode_ui() to return NULL and
decode_ui() to do nothing.  This commit allows them to instead specify
the relevant function pointers as NULL, in which case the mid-end won't
try to call them.

I'm planning to add a parameter to decode_ui(), and if I'm going to have
to touch every back-end's version of decode_ui(), I may as well ensure
that most of them never need to be touched again.  And obviously
encode_ui() should go the same way for symmetry.


--- a/bridges.c
+++ b/bridges.c
@@ -2141,15 +2141,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3294,8 +3285,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/cube.c
+++ b/cube.c
@@ -1038,15 +1038,6 @@
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1771,8 +1762,8 @@
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
--- a/devel.but
+++ b/devel.but
@@ -885,6 +885,9 @@
 determined to cheat, they could just as easily modify the game's
 source.)
 
+The \cw{encode_ui()} function is optional.  If a back-end doesn't need
+this function it can just set the pointer to \cw{NULL}.
+
 \S{backend-decode-ui} \cw{decode_ui()}
 
 \c void (*decode_ui)(game_ui *ui, const char *encoding);
@@ -895,6 +898,9 @@
 the best it can, which might just mean not changing the \c{game_ui}
 structure at all.  This might happen if a save file is corrupted, or
 simply from a newer version that encodes more \c{game_ui} data.
+
+Like \cw{encode_ui()}, \cw{decode_ui()} is optional.  If a back-end
+doesn't need this function it can just set the pointer to \cw{NULL}.
 
 \S{backend-changed-state} \cw{changed_state()}
 
--- a/dominosa.c
+++ b/dominosa.c
@@ -2727,15 +2727,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3446,8 +3437,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/fifteen.c
+++ b/fifteen.c
@@ -458,15 +458,6 @@
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1105,8 +1096,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
--- a/filling.c
+++ b/filling.c
@@ -1413,15 +1413,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2179,8 +2170,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
--- a/flip.c
+++ b/flip.c
@@ -926,15 +926,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1348,8 +1339,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/flood.c
+++ b/flood.c
@@ -790,15 +790,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1376,8 +1367,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/galaxies.c
+++ b/galaxies.c
@@ -2701,15 +2701,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -4137,8 +4128,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
 #ifdef EDITOR
--- a/keen.c
+++ b/keen.c
@@ -1544,15 +1544,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2488,8 +2479,8 @@
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
--- a/lightup.c
+++ b/lightup.c
@@ -1848,17 +1848,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    /* nothing to encode. */
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-    /* nothing to decode. */
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2343,8 +2332,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/loopy.c
+++ b/loopy.c
@@ -879,15 +879,6 @@
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3681,8 +3672,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
--- a/magnets.c
+++ b/magnets.c
@@ -1745,15 +1745,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2468,8 +2459,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/map.c
+++ b/map.c
@@ -2302,15 +2302,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3267,8 +3258,8 @@
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/midend.c
+++ b/midend.c
@@ -2204,7 +2204,7 @@
     /*
      * Any required serialisation of the game_ui.
      */
-    if (me->ui) {
+    if (me->ui && me->ourgame->encode_ui) {
         char *s = me->ourgame->encode_ui(me->ui);
         if (s) {
             wr("UI", s);
@@ -2541,7 +2541,7 @@
     }
 
     data.ui = me->ourgame->new_ui(data.states[0].state);
-    if (data.uistr)
+    if (data.uistr && me->ourgame->decode_ui)
         me->ourgame->decode_ui(data.ui, data.uistr);
 
     /*
--- a/mosaic.c
+++ b/mosaic.c
@@ -1022,15 +1022,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1620,8 +1611,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/netslide.c
+++ b/netslide.c
@@ -983,15 +983,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 /* ----------------------------------------------------------------------
  * Process a move.
  */
@@ -1869,8 +1860,8 @@
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/nullgame.c
+++ b/nullgame.c
@@ -121,15 +121,6 @@
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -248,8 +239,8 @@
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
--- a/palisade.c
+++ b/palisade.c
@@ -887,15 +887,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1388,8 +1379,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
--- a/pattern.c
+++ b/pattern.c
@@ -1250,15 +1250,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2087,8 +2078,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/pearl.c
+++ b/pearl.c
@@ -1878,15 +1878,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2729,8 +2720,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/pegs.c
+++ b/pegs.c
@@ -813,15 +813,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1372,8 +1363,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/range.c
+++ b/range.c
@@ -1240,15 +1240,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static const char *current_key_label(const game_ui *ui,
                                      const game_state *state, int button)
 {
@@ -1831,8 +1822,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/rect.c
+++ b/rect.c
@@ -2220,15 +2220,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void coord_round(float x, float y, int *xr, int *yr)
 {
     float xs, ys, xv, yv, dx, dy, dist;
@@ -3004,8 +2995,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/samegame.c
+++ b/samegame.c
@@ -1077,15 +1077,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void sel_clear(game_ui *ui, const game_state *state)
 {
     int i;
@@ -1677,8 +1668,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/signpost.c
+++ b/signpost.c
@@ -1410,15 +1410,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2293,8 +2284,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/singles.c
+++ b/singles.c
@@ -1461,15 +1461,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1861,8 +1852,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/sixteen.c
+++ b/sixteen.c
@@ -584,15 +584,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1202,8 +1193,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/slant.c
+++ b/slant.c
@@ -1595,15 +1595,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2186,8 +2177,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/solo.c
+++ b/solo.c
@@ -4573,15 +4573,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -5639,8 +5630,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
--- a/tents.c
+++ b/tents.c
@@ -1468,15 +1468,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2656,8 +2647,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/towers.c
+++ b/towers.c
@@ -1177,15 +1177,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2063,8 +2054,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
--- a/tracks.c
+++ b/tracks.c
@@ -2033,15 +2033,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -3056,8 +3047,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/twiddle.c
+++ b/twiddle.c
@@ -632,15 +632,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1316,8 +1307,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/undead.c
+++ b/undead.c
@@ -1661,16 +1661,6 @@
     return;
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-    return;
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2796,8 +2786,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
--- a/unequal.c
+++ b/unequal.c
@@ -1454,15 +1454,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2163,8 +2154,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     game_request_keys,
     game_changed_state,
     current_key_label,
--- a/unfinished/group.c
+++ b/unfinished/group.c
@@ -1272,15 +1272,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2332,8 +2323,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/unfinished/separate.c
+++ b/unfinished/separate.c
@@ -705,15 +705,6 @@
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -845,8 +836,8 @@
     false, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
--- a/unfinished/slide.c
+++ b/unfinished/slide.c
@@ -1217,15 +1217,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2337,8 +2328,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
--- a/unfinished/sokoban.c
+++ b/unfinished/sokoban.c
@@ -927,15 +927,6 @@
 {
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1459,8 +1450,8 @@
     false, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */
--- a/unruly.c
+++ b/unruly.c
@@ -1527,15 +1527,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -2039,8 +2030,8 @@
     true, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     current_key_label,
--- a/untangle.c
+++ b/untangle.c
@@ -1055,15 +1055,6 @@
     sfree(ui);
 }
 
-static char *encode_ui(const game_ui *ui)
-{
-    return NULL;
-}
-
-static void decode_ui(game_ui *ui, const char *encoding)
-{
-}
-
 static void game_changed_state(game_ui *ui, const game_state *oldstate,
                                const game_state *newstate)
 {
@@ -1465,8 +1456,8 @@
     false, NULL, NULL, /* can_format_as_text_now, text_format */
     new_ui,
     free_ui,
-    encode_ui,
-    decode_ui,
+    NULL, /* encode_ui */
+    NULL, /* decode_ui */
     NULL, /* game_request_keys */
     game_changed_state,
     NULL, /* current_key_label */