Major cleanups. Pre-process loop back in main loop, pre-processing abstracted into...
[open-adventure.git] / main.c
diff --git a/main.c b/main.c
index c53939cb5ed673a0ac6a79b206b28ca1f0969da1..1c1c6c4385299a0e7986fd2c91751d666dfb6761 100644 (file)
--- a/main.c
+++ b/main.c
@@ -1,17 +1,7 @@
 /*
- * There used to be a note that said this:
- *
- * The author - Don Woods - apologises for the style of the code; it
- * is a result of running the original Fortran IV source through a
- * home-brew Fortran-to-C converter.
- *
- * Now that the code has been restructured into something much closer
- * to idiomatic C, the following is more appropriate:
- *
- * ESR apologizes for the remaing gotos (now confined to one function
- * in this file - there used to be over 350 of them, *everywhere*),
- * and for the offensive globals.  Applying the Structured Program
- * Theorem can be hard.
+ * Copyright (c) 1977, 2005 by Will Crowther and Don Woods
+ * Copyright (c) 2017 by Eric S. Raymond
+ * SPDX-License-Identifier: BSD-2-clause
  */
 
 #include <stdlib.h>
@@ -86,7 +76,6 @@ int main(int argc, char *argv[])
                 fprintf(stderr,
                         "advent: can't open save file %s for read\n",
                         optarg);
-            signal(SIGINT, sig_handler);
             break;
 #endif
         default:
@@ -134,23 +123,6 @@ int main(int argc, char *argv[])
     terminate(quitgame);
 }
 
-static bool fallback_handler(struct command_t command)
-/* fallback handler for commands not handled by FORTRANish parser */
-{
-    long sv;
-    char buf[LINESIZE];
-    sprintf(buf, "%s %s", command.raw1, command.raw2);
-
-    if (sscanf(buf, "seed %ld", &sv) == 1) {
-        set_seed(sv);
-        printf("Seed set to %ld\n", sv);
-        // autogenerated, so don't charge user time for it.
-        --game.turns;
-        return true;
-    }
-    return false;
-}
-
 /*  Check if this loc is eligible for any hints.  If been here long
  *  enough, display.  Ignore "HINTS" < 4 (special stuff, see database
  *  notes). */
@@ -224,9 +196,8 @@ static void checkhints(void)
                         break;
                     game.hintlc[hint] = 0;
                     return;
-                default:
+                default: // LCOV_EXCL_LINE
                     BUG(HINT_NUMBER_EXCEEDS_GOTO_LIST); // LCOV_EXCL_LINE
-                    break;
                 }
 
                 /* Fall through to hint display */
@@ -240,6 +211,8 @@ static void checkhints(void)
             }
         }
     }
+
+
 }
 
 static bool spotted_by_pirate(int i)
@@ -247,12 +220,12 @@ static bool spotted_by_pirate(int i)
     if (i != PIRATE)
         return false;
 
-    /*  The pirate's spotted him.  He leaves him alone once we've
+    /*  The pirate's spotted him.  Pirate leaves him alone once we've
      *  found chest.  K counts if a treasure is here.  If not, and
      *  tally=1 for an unseen chest, let the pirate be spotted.  Note
      *  that game.place[CHEST] = LOC_NOWHERE might mean that he's thrown
      *  it to the troll, but in that case he's seen the chest
-     *  (game.prop=0). */
+     *  (game.prop[CHEST] == STATE_FOUND). */
     if (game.loc == game.chloc ||
         game.prop[CHEST] != STATE_NOTFOUND)
         return true;
@@ -316,21 +289,20 @@ static bool dwarfmove(void)
 /* Dwarves move.  Return true if player survives, false if he dies. */
 {
     int kk, stick, attack;
-    long tk[21];
+    loc_t tk[21];
 
     /*  Dwarf stuff.  See earlier comments for description of
      *  variables.  Remember sixth dwarf is pirate and is thus
      *  very different except for motion rules. */
 
-    /*  First off, don't let the dwarves follow him into a pit or
-     *  a wall.  Activate the whole mess the first time he gets as
-     *  far as the hall of mists (loc 15).  If game.newloc is
-     *  forbidden to pirate (in particular, if it's beyond the
+    /*  First off, don't let the dwarves follow him into a pit or a
+     *  wall.  Activate the whole mess the first time he gets as far
+     *  as the Hall of Mists (what INDEEP() tests).  If game.newloc
+     *  is forbidden to pirate (in particular, if it's beyond the
      *  troll bridge), bypass dwarf stuff.  That way pirate can't
      *  steal return toll, and dwarves can't meet the bear.  Also
      *  means dwarves won't follow him into dead end in maze, but
-     *  c'est la vie.  They'll wait for him outside the dead
-     *  end. */
+     *  c'est la vie.  They'll wait for him outside the dead end. */
     if (game.loc == LOC_NOWHERE ||
         FORCED(game.loc) ||
         CNDBIT(game.newloc, COND_NOARRR))
@@ -344,7 +316,7 @@ static bool dwarfmove(void)
     }
 
     /*  When we encounter the first dwarf, we kill 0, 1, or 2 of
-     *  the 5 dwarves.  If any of the survivors is at loc,
+     *  the 5 dwarves.  If any of the survivors is at game.loc,
      *  replace him with the alternate. */
     if (game.dflag == 1) {
         if (!INDEEP(game.loc) ||
@@ -399,7 +371,8 @@ static bool dwarfmove(void)
                 else if (j > 1 && game.newloc == tk[j - 1])
                     continue;
                 else if (j >= DIM(tk) - 1)
-                    continue;
+                    /* This can't actually happen. */
+                    continue; // LCOV_EXCL_LINE
                 else if (game.newloc == game.dloc[i])
                     continue;
                 else if (FORCED(game.newloc))
@@ -449,7 +422,7 @@ static bool dwarfmove(void)
         rspeak(stick > 1 ? MULTIPLE_HITS : (stick == 1 ? ONE_HIT : NONE_HIT), stick);
     } else {
         rspeak(KNIFE_THROWN);
-        rspeak(MISSES_YOU);
+        rspeak(stick ? GETS_YOU : MISSES_YOU);
     }
     if (stick == 0)
         return true;
@@ -476,10 +449,11 @@ static bool dwarfmove(void)
  *  building (and heaven help him if he tries to xyzzy back into the
  *  cave without the lamp!).  game.oldloc is zapped so he can't just
  *  "retreat". */
-
 static void croak(void)
 /*  Okay, he's dead.  Let's get on with it. */
 {
+    if (game.numdie < 0)
+        game.numdie = 0;  // LCOV_EXCL_LINE
     const char* query = obituaries[game.numdie].query;
     const char* yes_response = obituaries[game.numdie].yes_response;
     ++game.numdie;
@@ -488,8 +462,8 @@ static void croak(void)
          *  death and exit. */
         rspeak(DEATH_CLOSING);
         terminate(endgame);
-    } else if (game.numdie == NDEATHS ||
-               !yes(query, yes_response, arbitrary_messages[OK_MAN]))
+    } else if ( !yes(query, yes_response, arbitrary_messages[OK_MAN])
+                || game.numdie == NDEATHS)
         terminate(endgame);
     else {
         game.place[WATER] = game.place[OIL] = LOC_NOWHERE;
@@ -506,7 +480,7 @@ static void croak(void)
     }
 }
 
-static bool traveleq(long a, long b)
+static bool traveleq(int a, int b)
 /* Are two travel entries equal for purposes of skip after failed condition? */
 {
     return (travel[a].condtype == travel[b].condtype)
@@ -523,7 +497,6 @@ static bool traveleq(long a, long b)
  *  does, game.newloc will be limbo, and game.oldloc will be what killed
  *  him, so we need game.oldlc2, which is the last place he was
  *  safe.) */
-
 static void playermove( int motion)
 {
     int scratchloc, travel_entry = tkey[game.loc];
@@ -541,40 +514,39 @@ static void playermove( int motion)
             motion = game.oldlc2;
         game.oldlc2 = game.oldloc;
         game.oldloc = game.loc;
-        int spk = 0;
-        if (motion == game.loc)
-            spk = FORGOT_PATH;
-        if (CNDBIT(game.loc, COND_NOBACK))
-            spk = TWIST_TURN;
-        if (spk == 0) {
-            int te_tmp = 0;
-            for (;;) {
-                enum desttype_t desttype = travel[travel_entry].desttype;
-                scratchloc = travel[travel_entry].destval;
-                if (desttype != dest_goto || scratchloc != motion) {
-                    if (desttype == dest_goto) {
-                        if (FORCED(scratchloc) && travel[tkey[scratchloc]].destval == motion)
-                            te_tmp = travel_entry;
-                    }
-                    if (!travel[travel_entry].stop) {
-                        ++travel_entry;        /* go to next travel entry for this location */
-                        continue;
-                    }
-                    /* we've reached the end of travel entries for game.loc */
-                    travel_entry = te_tmp;
-                    if (travel_entry == 0) {
-                        rspeak(NOT_CONNECTED);
-                        return;
-                    }
-                }
+        if (CNDBIT(game.loc, COND_NOBACK)) {
+            rspeak(TWIST_TURN);
+            return;
+        }
+        if (motion == game.loc) {
+            rspeak(FORGOT_PATH);
+            return;
+        }
 
-                motion = travel[travel_entry].motion;
-                travel_entry = tkey[game.loc];
-                break; /* fall through to ordinary travel */
+        int te_tmp = 0;
+        for (;;) {
+            enum desttype_t desttype = travel[travel_entry].desttype;
+            scratchloc = travel[travel_entry].destval;
+            if (desttype != dest_goto || scratchloc != motion) {
+                if (desttype == dest_goto) {
+                    if (FORCED(scratchloc) && travel[tkey[scratchloc]].destval == motion)
+                        te_tmp = travel_entry;
+                }
+                if (!travel[travel_entry].stop) {
+                    ++travel_entry;    /* go to next travel entry for this location */
+                    continue;
+                }
+                /* we've reached the end of travel entries for game.loc */
+                travel_entry = te_tmp;
+                if (travel_entry == 0) {
+                    rspeak(NOT_CONNECTED);
+                    return;
+                }
             }
-        } else {
-            rspeak(spk);
-            return;
+
+            motion = travel[travel_entry].motion;
+            travel_entry = tkey[game.loc];
+            break; /* fall through to ordinary travel */
         }
     } else if (motion == LOOK) {
         /*  Look.  Can't give more detail.  Pretend it wasn't dark
@@ -645,7 +617,6 @@ static void playermove( int motion)
     /* (ESR) We've found a destination that goes with the motion verb.
      * Next we need to check any conditional(s) on this destination, and
      * possibly on following entries. */
-    /* FIXME: Magic numbers related to move opcodes */
     do {
         for (;;) { /* L12 loop */
             for (;;) {
@@ -670,7 +641,7 @@ static void playermove( int motion)
 
                 /* We arrive here on conditional failure.
                  * Skip to next non-matching destination */
-                long te_tmp = travel_entry;
+                int te_tmp = travel_entry;
                 do {
                     if (travel[te_tmp].stop)
                         BUG(CONDITIONAL_TRAVEL_ENTRY_WITH_NO_ALTERATION); // LCOV_EXCL_LINE
@@ -714,14 +685,16 @@ static void playermove( int motion)
                      * to get it out.  Having dropped it, go back and
                      * pretend he wasn't carrying it after all. */
                     drop(EMERALD, game.loc);
-                    int te_tmp = travel_entry;
-                    do {
-                        if (travel[te_tmp].stop)
-                            BUG(CONDITIONAL_TRAVEL_ENTRY_WITH_NO_ALTERATION); // LCOV_EXCL_LINE
-                        ++te_tmp;
-                    } while
-                    (traveleq(travel_entry, te_tmp));
-                    travel_entry = te_tmp;
+                    {
+                        int te_tmp = travel_entry;
+                        do {
+                            if (travel[te_tmp].stop)
+                                BUG(CONDITIONAL_TRAVEL_ENTRY_WITH_NO_ALTERATION); // LCOV_EXCL_LINE
+                            ++te_tmp;
+                        } while
+                        (traveleq(travel_entry, te_tmp));
+                        travel_entry = te_tmp;
+                    }
                     continue; /* goto L12 */
                 case 3:
                     /* Special travel 3.  Troll bridge.  Must be done
@@ -729,12 +702,13 @@ static void playermove( int motion)
                      * wander across and encounter the bear.  (They
                      * won't follow the player there because that
                      * region is forbidden to the pirate.)  If
-                     * game.prop(TROLL)=1, he's crossed since paying,
-                     * so step out and block him.  (standard travel
-                     * entries check for game.prop(TROLL)=0.)  Special
-                     * stuff for bear. */
+                     * game.prop[TROLL]=TROLL_PAIDONCE, he's crossed
+                     * since paying, so step out and block him.
+                     * (standard travel entries check for
+                     * game.prop[TROLL]=TROLL_UNPAID.)  Special stuff
+                     * for bear. */
                     if (game.prop[TROLL] == TROLL_PAIDONCE) {
-                        pspeak(TROLL, look, TROLL_PAIDONCE, true);
+                        pspeak(TROLL, look, true, TROLL_PAIDONCE);
                         game.prop[TROLL] = TROLL_UNPAID;
                         move(TROLL2, LOC_NOWHERE);
                         move(TROLL2 + NOBJECTS, IS_FREE);
@@ -758,7 +732,7 @@ static void playermove( int motion)
                         croak();
                         return;
                     }
-                default:
+                default: // LCOV_EXCL_LINE
                     BUG(SPECIAL_TRAVEL_500_GT_L_GT_300_EXCEEDS_GOTO_LIST); // LCOV_EXCL_LINE
                 }
             }
@@ -768,6 +742,50 @@ static void playermove( int motion)
     (false);
 }
 
+static void lampcheck(void)
+/* Check game limit and lamp timers */
+{
+    if (game.prop[LAMP] == LAMP_BRIGHT)
+        --game.limit;
+
+    /*  Another way we can force an end to things is by having the
+     *  lamp give out.  When it gets close, we come here to warn him.
+     *  First following arm checks if the lamp and fresh batteries are
+     *  here, in which case we replace the batteries and continue.
+     *  Second is for other cases of lamp dying.  Even after it goes
+     *  out, he can explore outside for a while if desired. */
+    if (game.limit <= WARNTIME) {
+        if (HERE(BATTERY) && game.prop[BATTERY] == FRESH_BATTERIES && HERE(LAMP)) {
+            rspeak(REPLACE_BATTERIES);
+            game.prop[BATTERY] = DEAD_BATTERIES;
+#ifdef __unused__
+            /* This code from the original game seems to have been faulty.
+             * No tests ever passed the guard, and with the guard removed
+             * the game hangs when the lamp limit is reached.
+             */
+            if (TOTING(BATTERY))
+                drop(BATTERY, game.loc);
+#endif
+            game.limit += BATTERYLIFE;
+            game.lmwarn = false;
+        } else if (!game.lmwarn && HERE(LAMP)) {
+            game.lmwarn = true;
+            if (game.prop[BATTERY] == DEAD_BATTERIES)
+                rspeak(MISSING_BATTERIES);
+            else if (game.place[BATTERY] == LOC_NOWHERE)
+                rspeak(LAMP_DIM);
+            else
+                rspeak(GET_BATTERIES);
+        }
+    }
+    if (game.limit == 0) {
+        game.limit = -1;
+        game.prop[LAMP] = LAMP_DARK;
+        if (HERE(LAMP))
+            rspeak(LAMP_OUT);
+    }
+}
+
 static bool closecheck(void)
 /*  Handle the closing of the cave.  The cave closes "clock1" turns
  *  after the last treasure has been located (including the pirate's
@@ -788,6 +806,15 @@ static bool closecheck(void)
  *  problems arise from the use of negative prop numbers to suppress
  *  the object descriptions until he's actually moved the objects. */
 {
+    /* If a turn threshold has been met, apply penalties and tell
+     * the player about it. */
+    for (int i = 0; i < NTHRESHOLDS; ++i) {
+        if (game.turns == turn_thresholds[i].threshold + 1) {
+            game.trnluz += turn_thresholds[i].point_loss;
+            speak(turn_thresholds[i].message);
+        }
+    }
+
     /*  Don't tick game.clock1 unless well into cave (and not at Y2). */
     if (game.tally == 0 && INDEEP(game.loc) && game.loc != LOC_Y2)
         --game.clock1;
@@ -826,7 +853,7 @@ static bool closecheck(void)
         rspeak(CAVE_CLOSING);
         game.clock1 = -1;
         game.closng = true;
-        return true;
+        return game.closed;
     } else if (game.clock1 < 0)
         --game.clock2;
     if (game.clock2 == 0) {
@@ -875,50 +902,13 @@ static bool closecheck(void)
 
         rspeak(CAVE_CLOSED);
         game.closed = true;
-        return true;
+        return game.closed;
     }
 
+    lampcheck();
     return false;
 }
 
-static void lampcheck(void)
-/* Check game limit and lamp timers */
-{
-    if (game.prop[LAMP] == LAMP_BRIGHT)
-        --game.limit;
-
-    /*  Another way we can force an end to things is by having the
-     *  lamp give out.  When it gets close, we come here to warn him.
-     *  First following arm checks if the lamp and fresh batteries are
-     *  here, in which case we replace the batteries and continue.
-     *  Second is for other cases of lamp dying.  Eve after it goes
-     *  out, he can explore outside for a while if desired. */
-    if (game.limit <= WARNTIME) {
-        if (HERE(BATTERY) && game.prop[BATTERY] == FRESH_BATTERIES && HERE(LAMP)) {
-            rspeak(REPLACE_BATTERIES);
-            game.prop[BATTERY] = DEAD_BATTERIES;
-            if (TOTING(BATTERY))
-                drop(BATTERY, game.loc);
-            game.limit += BATTERYLIFE;
-            game.lmwarn = false;
-        } else if (!game.lmwarn && HERE(LAMP)) {
-            game.lmwarn = true;
-            if (game.prop[BATTERY] == DEAD_BATTERIES)
-                rspeak(MISSING_BATTERIES);
-            else if (game.place[BATTERY] == LOC_NOWHERE)
-                rspeak(LAMP_DIM);
-            else
-                rspeak(GET_BATTERIES);
-        }
-    }
-    if (game.limit == 0) {
-        game.limit = -1;
-        game.prop[LAMP] = LAMP_DARK;
-        if (HERE(LAMP))
-            rspeak(LAMP_OUT);
-    }
-}
-
 static void listobjects(void)
 /*  Print out descriptions of objects at this location.  If
  *  not closing and property value is negative, tally off
@@ -931,7 +921,7 @@ static void listobjects(void)
     if (!DARK(game.loc)) {
         ++game.abbrev[game.loc];
         for (int i = game.atloc[game.loc]; i != 0; i = game.link[i]) {
-            long obj = i;
+            obj_t obj = i;
             if (obj > NOBJECTS)
                 obj = obj - NOBJECTS;
             if (obj == STEPS && TOTING(NUGGET))
@@ -965,53 +955,108 @@ static void listobjects(void)
                 kk = (game.loc == game.fixed[STEPS])
                      ? STEPS_UP
                      : STEPS_DOWN;
-            pspeak(obj, look, kk, true);
+            pspeak(obj, look, true, kk);
         }
     }
 }
 
-static bool get_command_input(struct command_t *command)
+void clear_command(command_t *cmd)
 {
-    char inputbuf[LINESIZE];
-    char word1[TOKLEN + 1];
-    char word2[TOKLEN + 1];
-    char* input;
+    cmd->verb = ACT_NULL;
+    game.oldobj = cmd->obj;
+    cmd->obj = NO_OBJECT;
+}
 
-    for (;;) {
-        input = get_input();
-        if (input == NULL)
-            return false;
-        if (word_count(input) > 2) {
-            rspeak(TWO_WORDS);
-            free(input);
-            continue;
+void close_cleanup_before_command(void) 
+/*  If closing time, check for any objects being toted with
+ *  game.prop < 0 and stash them.  This way objects won't be
+ *  described until they've been picked up and put down
+ *  separate from their respective piles. */
+{
+    if (game.closed) {
+        if (game.prop[OYSTER] < 0 && TOTING(OYSTER))
+            pspeak(OYSTER, look, true, 1);
+        for (size_t i = 1; i <= NOBJECTS; i++) {
+            if (TOTING(i) && game.prop[i] < 0)
+                game.prop[i] = STASHED(i);
         }
-        if (strcmp(input, "") != 0)
-            break;
-        free(input);
     }
+}
 
-    strncpy(inputbuf, input, LINESIZE - 1);
-    free(input);
+bool preprocess_command(command_t *command) 
+/* Pre-processes a command input to see if we need to tease out a few specific cases:
+ * - "enter water" or "enter stream": 
+ *   wierd specific case that gets the user wet, and then kicks us back to get another command
+ * - <object> <verb>:
+ *   Irregular form of input, but should be allowed. We switch back to <verb> <object> form for 
+ *   furtherprocessing.
+ * - "grate":
+ *   If in location with grate, we move to that grate. If we're in a number of other places, 
+ *   we move to the entrance.
+ * - "water plant", "oil plant", "water door", "oil door":
+ *   Change to "pour water" or "pour oil" based on context
+ * - "cage bird":
+ *   If bird is present, we change to "carry bird"
+ *
+ * Returns true if pre-processing is complete, and we're ready to move to the primary command 
+ * processing, false otherwise. */
+{
+    if (command->word[0].type == MOTION && command->word[0].id == ENTER
+        && (command->word[1].id == STREAM || command->word[1].id == WATER)) {
+        if (LIQLOC(game.loc) == WATER)
+            rspeak(FEET_WET);
+        else
+            rspeak(WHERE_QUERY);
+    } else {
+        if (command->word[0].type == OBJECT) {
+            /* From OV to VO form */
+            if (command->word[1].type == ACTION) {
+                command_word_t stage = command->word[0];
+                command->word[0] = command->word[1];
+                command->word[1] = stage;
+            }
 
-    tokenize(inputbuf, command);
+            if (command->word[0].id == GRATE) {
+                command->word[0].type = MOTION;
+                if (game.loc == LOC_START ||
+                    game.loc == LOC_VALLEY ||
+                    game.loc == LOC_SLIT) {
+                    command->word[0].id = DEPRESSION;
+                }
+                if (game.loc == LOC_COBBLE ||
+                    game.loc == LOC_DEBRIS ||
+                    game.loc == LOC_AWKWARD ||
+                    game.loc == LOC_BIRD ||
+                    game.loc == LOC_PITTOP) {
+                    command->word[0].id = ENTRANCE;
+                }
+            }
+            if ((command->word[0].id == WATER || command->word[0].id == OIL) && 
+                (command->word[1].id == PLANT || command->word[1].id == DOOR)) {
+                if (AT(command->word[1].id)) {
+                    command->word[1] = command->word[0];
+                    command->word[0].id = POUR;
+                    command->word[0].type = ACTION;
+                    strncpy(command->word[0].raw, "pour", LINESIZE - 1);
+                }
+            }
+            if (command->word[0].id == CAGE && command->word[1].id == BIRD && HERE(CAGE) && HERE(BIRD)) {
+                command->word[0].id = CARRY;
+                command->word[0].type = ACTION;
+            }
+        }
 
-    packed_to_token(command->wd1, word1);
-    packed_to_token(command->wd2, word2);
-    command->id1 = get_vocab_id(word1);
-    command->id2 = get_vocab_id(word2);
-    
-    return true;
+        return true;
+    }
+    return false;
 }
 
 static bool do_command()
 /* Get and execute a command */
 {
-    long kmod, defn;
-    static struct command_t command;
-    char word1[TOKLEN + 1];
-
-    command.verb = 0;
+    static command_t command;
+    bool command_given = false;
+    bool command_executed = false;
 
     /*  Can't leave cave once it's closing (except by main office). */
     if (OUTSID(game.newloc) && game.newloc != 0 && game.closng) {
@@ -1041,7 +1086,6 @@ static bool do_command()
         croak();
 
     /*  Describe the current location and (maybe) get next command. */
-
     for (;;) {
         if (game.loc == 0)
             croak();
@@ -1071,147 +1115,123 @@ static bool do_command()
             rspeak(SAYS_PLUGH);
 
         listobjects();
+        clear_command(&command);
 
-Lclearobj:
-        game.oldobj = command.obj;
-
-        checkhints();
-
-        /*  If closing time, check for any objects being toted with
-         *  game.prop < 0 and stash them.  This way objects won't be
-         *  described until they've been picked up and put down
-         *  separate from their respective piles. */
-        if (game.closed) {
-            if (game.prop[OYSTER] < 0 && TOTING(OYSTER))
-                pspeak(OYSTER, look, 1, true);
-            for (size_t i = 1; i <= NOBJECTS; i++) {
-                if (TOTING(i) && game.prop[i] < 0)
-                    game.prop[i] = STASHED(i);
-            }
-        }
-        game.wzdark = DARK(game.loc);
-        if (game.knfloc > 0 && game.knfloc != game.loc)
-            game.knfloc = 0;
-        
-        // Get command input from user
-        if(!get_command_input(&command)) 
-            return false;
-
-Lthreshold:
-        ++game.turns;
-
-        /* If a turn threshold has been met, apply penalties and tell
-         * the player about it. */
-        for (int i = 0; i < NTHRESHOLDS; ++i) {
-            if (game.turns == turn_thresholds[i].threshold + 1) {
-                game.trnluz += turn_thresholds[i].point_loss;
-                speak(turn_thresholds[i].message);
-            }
-        }
+        // Keep getting commands from user until valid command is both given and executed.
+        do {
+            // Check some quick-time game state items, get input from user, increment turn, 
+            // and pre-process commands. Keep going until pre-processing is done.
+            do {
+                checkhints();
+                close_cleanup_before_command();
+
+                game.wzdark = DARK(game.loc);
+                if (game.knfloc > 0 && game.knfloc != game.loc)
+                    game.knfloc = 0;
+
+                // Get command input from user
+                if (!get_command_input(&command))
+                    return false;
 
-        if (closecheck()) {
-            if (game.closed)
+                ++game.turns;
+            } while ( !preprocess_command(&command));
+            command_given = true;
+
+            // check if game is closed
+            if (closecheck() ) 
                 return true;
-        } else
-            lampcheck();
 
-        if (command.id1 == ENTER && (command.id2 == STREAM ||
-                                     command.id2 == PROMOTE_WORD(WATER))) {
-            if (LIQLOC(game.loc) == WATER) {
-                rspeak(FEET_WET);
-            } else {
-                rspeak(WHERE_QUERY);
-            }
-            goto Lclearobj;
-        }
-        if (command.id1 == ENTER && command.id2 != WORD_NOT_FOUND && command.id2 != WORD_EMPTY) {
-            command.id1 = command.id2;
-            command.id2 = WORD_EMPTY;
-        } else {
-            /* FIXME: Magic numbers related to vocabulary */
-            if (!((command.id1 != PROMOTE_WORD(WATER) && command.id1 != PROMOTE_WORD(OIL)) ||
-                  (command.id2 != PROMOTE_WORD(PLANT) && command.id2 != PROMOTE_WORD(DOOR)))) {
-                if (AT(DEMOTE_WORD(command.id2)))
-                    command.wd2 = token_to_packed("POUR");
-            }
-            if (command.id1 == PROMOTE_WORD(CAGE) && command.id2 == PROMOTE_WORD(BIRD) && HERE(CAGE) && HERE(BIRD))
-                command.wd1 = token_to_packed("CATCH");
-        }
-Lookup:
-        if (wordeq(command.wd1, token_to_packed("WEST"))) {
-            if (++game.iwest == 10)
-                rspeak(W_IS_WEST);
-        }
-        if (wordeq(command.wd1, token_to_packed("GO")) && !wordempty(command.wd2)) {
-            if (++game.igo == 10)
-                rspeak(GO_UNNEEDED);
-        }
-        packed_to_token(command.wd1, word1);
-        defn = get_vocab_id(word1);
-        if (defn == WORD_NOT_FOUND) {
-            if (fallback_handler(command))
-                continue;
-            /* Gee, I don't understand. */
-            sspeak(DONT_KNOW, command.raw1);
-            goto Lclearobj;
-        }
-        /* FIXME: magic numbers related to vocabulary */
-        kmod = MOD(defn, 1000);
-        switch (defn / 1000) {
-        case 0:
-            playermove(kmod);
-            return true;
-        case 1:
-            command.part = unknown;
-            command.obj = kmod;
-            break;
-        case 2:
-            command.part = intransitive;
-            command.verb = kmod;
-            break;
-        case 3:
-            speak(specials[kmod].message);
-            goto Lclearobj;
-        default:
-            BUG(VOCABULARY_TYPE_N_OVER_1000_NOT_BETWEEN_0_AND_3); // LCOV_EXCL_LINE
-        }
-        
-        switch (action(&command)) {
-        case GO_TERMINATE:
-            return true;
-        case GO_MOVE:
-            playermove(NUL);
-            return true;
-        case GO_TOP:
-            continue;  /* back to top of main interpreter loop */
-        case GO_CHECKFOO:
-            goto Lthreshold;
-        case GO_LOOKUP:
-            goto Lookup;
-        case GO_WORD2:
-            /* Get second word for analysis. */
-            command.wd1 = command.wd2;
-            strncpy(command.raw1, command.raw2, LINESIZE - 1);
-            wordclear(&command.wd2);
-            command.raw2[0] = '\0';
-            goto Lookup;
-        case GO_UNKNOWN:
-            /*  Random intransitive verbs come here.  Clear obj just in case
-             *  (see attack()). */
-            command.raw1[0] = toupper(command.raw1[0]);
-            sspeak(DO_WHAT, command.raw1);
-            command.obj = 0;
-            // Fallthrough
-        case GO_CHECKHINT: // Fallthrough
-        case GO_CLEAROBJ:
-            goto Lclearobj;
-        case GO_DWARFWAKE:
-            /*  Oh dear, he's disturbed the dwarves. */
-            rspeak(DWARVES_AWAKEN);
-            terminate(endgame);
-        default:
-            BUG(ACTION_RETURNED_PHASE_CODE_BEYOND_END_OF_SWITCH); // LCOV_EXCL_LINE
-        }
+           // loop until all words in command are procesed
+            do {
+                // assume all words in command are processed, until proven otherwise
+                command_executed = true;
+
+                if (command.word[0].id == WORD_NOT_FOUND) {
+                    /* Gee, I don't understand. */
+                    sspeak(DONT_KNOW, command.word[0].raw);
+                    clear_command(&command);
+                    command_given = false;
+                    continue;
+                }
+
+                // Give user hints of shortcuts
+                if (strncasecmp(command.word[0].raw, "west", sizeof("west")) == 0) {
+                    if (++game.iwest == 10)
+                        rspeak(W_IS_WEST);
+                }
+                if (strncasecmp(command.word[0].raw, "go", sizeof("go")) == 0 && command.word[1].id != WORD_EMPTY) {
+                    if (++game.igo == 10)
+                        rspeak(GO_UNNEEDED);
+                }
+
+                switch (command.word[0].type) {
+                case NO_WORD_TYPE: // FIXME: treating NO_WORD_TYPE as a motion word is confusing
+                case MOTION:
+                    playermove(command.word[0].id);
+                    return true;
+                case OBJECT:
+                    command.part = unknown;
+                    command.obj = command.word[0].id;
+                    break;
+                case ACTION:
+                    if (command.word[1].type == NUMERIC)
+                        command.part = transitive;
+                    else
+                        command.part = intransitive;
+                    command.verb = command.word[0].id;
+                    break;
+                case NUMERIC:
+                    if (!settings.oldstyle) {
+                        sspeak(DONT_KNOW, command.word[0].raw);
+                        clear_command(&command);
+                        command_given = false;
+                        continue;
+                    }
+                    break;
+                default: // LCOV_EXCL_LINE
+                    BUG(VOCABULARY_TYPE_N_OVER_1000_NOT_BETWEEN_0_AND_3); // LCOV_EXCL_LINE
+                }
+
+                switch (action(command)) {
+                case GO_TERMINATE:
+                    return true;
+                case GO_MOVE:
+                    playermove(NUL);
+                    return true;
+                case GO_TOP:
+                    continue;    /* back to top of main interpreter loop */
+                case GO_CLEAROBJ:
+                    clear_command(&command);
+                /* FALL THROUGH */
+                case GO_CHECKHINT:
+                    command_given = false;
+                    break;
+                case GO_WORD2:
+#ifdef GDEBUG
+                    printf("Word shift\n");
+#endif /* GDEBUG */
+                    /* Get second word for analysis. */
+                    command.word[0] = command.word[1];
+                    command.word[1] = empty_command_word;
+                    command_executed = false;
+                    break;
+                case GO_UNKNOWN:
+                    /*  Random intransitive verbs come here.  Clear obj just in case
+                     *  (see attack()). */
+                    command.word[0].raw[0] = toupper(command.word[0].raw[0]);
+                    sspeak(DO_WHAT, command.word[0].raw);
+                    command.obj = 0;
+                    command_given = false;
+                    break;
+                case GO_DWARFWAKE:
+                    /*  Oh dear, he's disturbed the dwarves. */
+                    rspeak(DWARVES_AWAKEN);
+                    terminate(endgame);
+                default: // LCOV_EXCL_LINE
+                    BUG(ACTION_RETURNED_PHASE_CODE_BEYOND_END_OF_SWITCH); // LCOV_EXCL_LINE
+                }
+            } while (!command_executed);
+        } while (!command_given);
     }
 }