-extern long LNLENG, LNPOSN, PARMS[];
-extern char rawbuf[LINESIZE], INLINE[LINESIZE+1], MAP1[], MAP2[];
-extern FILE *logfp;
-extern bool oldstyle;
-extern lcg_state lcgstate;
-
-/* b is not needed for POSIX but harmless */
-#define READ_MODE "rb"
-#define WRITE_MODE "wb"
-
-extern void SPEAK(vocab_t);
-extern void PSPEAK(vocab_t,int);
-extern void RSPEAK(vocab_t);
-extern void SETPRM(long,long,long);
-extern bool GETIN(FILE *,token_t*,token_t*,token_t*,token_t*);
-extern long YES(FILE *,vocab_t,vocab_t,vocab_t);
-extern long GETTXT(bool,bool,bool);
-extern token_t MAKEWD(long);
-extern void PUTTXT(token_t,long*,long);
-extern void SHFTXT(long,long);
-extern void TYPE0(void);
-
-extern void fSAVWDS(long*,long*,long*,long*,long*,long*,long*);
-#define SAVWDS(W1,W2,W3,W4,W5,W6,W7) fSAVWDS(&W1,&W2,&W3,&W4,&W5,&W6,&W7)
-extern void fSAVARR(long*,long);
-#define SAVARR(ARR,N) fSAVARR(ARR,N)
-extern void fSAVWRD(long,long*);
-#define SAVWRD(OP,WORD) fSAVWRD(OP,&WORD)
-
-extern long VOCAB(long,long);
-extern void DSTROY(long);
-extern void JUGGLE(long);
-extern void MOVE(long,long);
-extern long PUT(long,long,long);
-extern void CARRY(long,long);
-extern void DROP(long,long);
-extern long ATDWRF(long);
-extern long SETBIT(long);
-extern bool TSTBIT(long,int);
-extern long RNDVOC(long,long);
-extern void BUG(long) __attribute__((noreturn));
-extern void MAPLIN(FILE *);
-extern void TYPE(void);
-extern void MPINIT(void);
-
-extern void fSAVEIO(long,long,long*);
-#define SAVEIO(OP,IN,ARR) fSAVEIO(OP,IN,ARR)
-extern void DATIME(long*, long*);
-
-extern long MOD(long,long);
-
-extern void set_seed(long);
-extern unsigned long get_next_lcg_value(void);
-extern long randrange(long);
-extern void score(long);
-
-/* Statement functions
- *
- * AT(OBJ) = true if on either side of two-placed object
- * CNDBIT(L,N) = true if COND(L) has bit n set (bit 0 is units bit)
- * DARK(DUMMY) = true if location "LOC" is dark
- * FORCED(LOC) = true if LOC moves without asking for input (COND=2)
- * FOREST(LOC) = true if LOC is part of the forest
- * GSTONE(OBJ) = true if OBJ is a gemstone
- * HERE(OBJ) = true if the OBJ is at "LOC" (or is being carried)
- * LIQ(DUMMY) = object number of liquid in bottle
- * LIQLOC(LOC) = object number of liquid (if any) at LOC
- * PCT(N) = true N% of the time (N integer from 0 to 100)
- * TOTING(OBJ) = true if the OBJ is being carried */
-
-#define TOTING(OBJ) (game.place[OBJ] == -1)
-#define AT(OBJ) (game.place[OBJ] == game.loc || game.fixed[OBJ] == game.loc)
-#define HERE(OBJ) (AT(OBJ) || TOTING(OBJ))
-#define LIQ2(PBOTL) ((1-(PBOTL))*WATER+((PBOTL)/2)*(WATER+OIL))
-#define LIQ(DUMMY) (LIQ2(game.prop[BOTTLE]<0 ? -1-game.prop[BOTTLE] : game.prop[BOTTLE]))
-#define LIQLOC(LOC) (LIQ2((MOD(COND[LOC]/2*2,8)-5)*MOD(COND[LOC]/4,2)+1))
-#define CNDBIT(L,N) (TSTBIT(COND[L],N))
-#define FORCED(LOC) (COND[LOC] == 2)
-#define DARK(DUMMY) ((!CNDBIT(game.loc,0)) && (game.prop[LAMP] == 0 || !HERE(LAMP)))
-#define PCT(N) (randrange(100) < (N))
-#define GSTONE(OBJ) ((OBJ) == EMRALD || (OBJ) == RUBY || (OBJ) == AMBER || (OBJ) == SAPPH)
-#define FOREST(LOC) ((LOC) >= 145 && (LOC) <= 166)
-#define VOCWRD(LETTRS,SECT) (VOCAB(MAKEWD(LETTRS),SECT))
-
-/* The following two functions were added to fix a bug (game.clock1 decremented
- * while in forest). They should probably be replaced by using another
- * "cond" bit. For now, however, a quick fix... OUTSID(LOC) is true if
- * LOC is outside, INDEEP(LOC) is true if LOC is "deep" in the cave (hall
- * of mists or deeper). Note special kludges for "Foof!" locs. */
-
-#define OUTSID(LOC) ((LOC) <= 8 || FOREST(LOC) || (LOC) == PLAC[SAPPH] || (LOC) == 180 || (LOC) == 182)
-#define INDEEP(LOC) ((LOC) >= 15 && !OUTSID(LOC) && (LOC) != 179)
-
-/* vocabulary items */
-extern long AMBER, ATTACK, AXE, BACK, BATTER, BEAR,
- BIRD, BLOOD, BOTTLE, CAGE, CAVE, CAVITY, CHAIN, CHASM, CHEST,
- CLAM, COINS, DOOR, DPRSSN, DRAGON, DWARF, EGGS,
- EMRALD, ENTER, ENTRNC, FIND, FISSUR, FOOD, GRATE, HINT, INVENT,
- JADE, KEYS, KNIFE, LAMP, LOCK, LOOK, MAGZIN, MESSAG, MIRROR, NUGGET, NUL,
- OGRE, OIL, OYSTER, PANIC, PEARL, PILLOW, PLANT, PLANT2, PYRAM,
- RESER, ROD, ROD2, RUBY, RUG, SAPPH, SAY, SIGN, SNAKE,
- STEPS, STICK, STREAM, THROW, TRIDNT, TROLL, TROLL2,
- URN, VASE, VEND, VOLCAN, WATER;
-/* everything else */
-extern long I, K, SPK, WD1, WD1X, WD2, WD2X;
+extern char *myreadline(const char *);
+extern bool get_command_input(command_t *);
+extern void clear_command(command_t *);
+extern void speak(const char*, ...);
+extern void sspeak(int msg, ...);
+extern void pspeak(vocab_t, enum speaktype, bool, int, ...);
+extern void rspeak(vocab_t, ...);
+extern void echo_input(FILE*, const char*, const char*);
+extern bool silent_yes_or_no(void);
+extern bool yes_or_no(const char*, const char*, const char*);
+extern void juggle(obj_t);
+extern void move(obj_t, loc_t);
+extern loc_t put(obj_t, loc_t, int);
+extern void carry(obj_t, loc_t);
+extern void drop(obj_t, loc_t);
+extern int atdwrf(loc_t);
+extern int setbit(int);
+extern bool tstbit(int, int);
+extern void set_seed(int32_t);
+extern int32_t randrange(int32_t);
+extern int score(enum termination);
+extern void terminate(enum termination) __attribute__((noreturn));
+extern int savefile(FILE *, int32_t);
+#if defined ADVENT_AUTOSAVE
+extern void autosave(void);
+#endif
+extern int suspend(void);
+extern int resume(void);
+extern int restore(FILE *);
+extern int initialise(void);
+extern phase_codes_t action(command_t);
+extern void state_change(obj_t, int);
+extern bool is_valid(struct game_t);
+
+void bug(enum bugtype, const char *) __attribute__((__noreturn__));
+
+/* represent an empty command word */
+static const command_word_t empty_command_word = {
+ .raw = "",
+ .id = WORD_EMPTY,
+ .type = NO_WORD_TYPE,
+};