Index: class.doc
==================================================================
--- class.doc
+++ class.doc
@@ -1052,10 +1052,19 @@
 
 c?  ( any -- bool )
   True if the value is a class, or false if it is any other type. Error if
   it is a sound.
 
+chain  ( any -- bool )
+  If given an object of the same class as the current object, selects that
+  object as the current object and continues executing the code with that
+  object instead. This new current object is not saved if you return from
+  a function or a subroutine call. If it successfully chained, then the
+  result is false. If given an object of a different class, an object that
+  doesn't exist, or anything other than an object, then it does nothing
+  and the result is true.
+
 Create  ( class x y image dir -- obj ) **
   Creates a new object at the specified location, and returns it. The
   result is zero if the class is zero, the coordinates are out of range,
   the object cannot be created due to the CollisionLayers, or if the new
   object is destroyed before its CREATE message returns.

Index: exec.c
==================================================================
--- exec.c
+++ exec.c
@@ -1301,10 +1301,18 @@
   if(!vstackptr) Throw("No mark");
   v=Pop();
   while(--p>vstackptr) if(v_equal(v,vstack[p])) return 1;
   return 0;
 }
+
+static Uint32 v_chain(Value v,Uint16 c) {
+  if(v.t==TY_SOUND || v.t==TY_USOUND) Throw("Cannot convert sound to object");
+  if(v.t<=TY_MAXTYPE) return VOIDLINK;
+  if(v.u>=nobjects || !objects[v.u] || objects[v.u]->generation!=v.t) return VOIDLINK;
+  if(objects[v.u]->class!=c) return VOIDLINK;
+  return v.u;
+}
 
 // Here is where the execution of a Free Hero Mesh bytecode subroutine is executed.
 #define NoIgnore() do{ changed=1; }while(0)
 #define GetVariableOf(a,b) (i=v_object(Pop()),i==VOIDLINK?NVALUE(0):b(objects[i]->a))
 #define GetVariableOrAttributeOf(a,b) (t2=Pop(),t2.t==TY_CLASS?NVALUE(classes[t2.u]->a):(i=v_object(t2),i==VOIDLINK?NVALUE(0):b(objects[i]->a)))
@@ -1393,10 +1401,11 @@
     case OP_BUSY_C: StackReq(1,1); GetFlagOf(OF_BUSY); break;
     case OP_BUSY_E: NoIgnore(); StackReq(1,0); if(v_bool(Pop())) o->oflags|=OF_BUSY; else o->oflags&=~OF_BUSY; break;
     case OP_BUSY_EC: NoIgnore(); StackReq(2,0); SetFlagOf(OF_BUSY); break;
     case OP_BXOR: StackReq(2,1); t2=Pop(); Numeric(t2); t1=Pop(); Numeric(t1); Push(NVALUE(t1.u^t2.u)); break;
     case OP_CALLSUB: execute_program(code,code[ptr++],obj); break;
+    case OP_CHAIN: StackReq(1,1); t1=Pop(); i=v_chain(t1,o->class); if(i==VOIDLINK) { Push(NVALUE(1)); } else { o=objects[obj=i]; Push(NVALUE(0)); } break;
     case OP_CLASS: StackReq(0,1); Push(CVALUE(o->class)); break;
     case OP_CLASS_C: StackReq(1,1); Push(GetVariableOf(class,CVALUE)); break;
     case OP_CLIMB: StackReq(0,1); Push(NVALUE(o->climb)); break;
     case OP_CLIMB_C: StackReq(1,1); Push(GetVariableOrAttributeOf(climb,NVALUE)); break;
     case OP_CLIMB_E: NoIgnore(); StackReq(1,0); t1=Pop(); Numeric(t1); o->climb=t1.u; break;

Index: instruc
==================================================================
--- instruc
+++ instruc
@@ -205,10 +205,11 @@
 .Broadcast
 *BroadcastClass ; for (Broadcast [class])
 .BroadcastEx ; broadcast with three arguments
 BroadcastSum ; Broadcast, but result is sum of return values
 BroadcastSumEx
+chain
 .Create
 DelInventory
 Delta
 .,Destroy
 FlushClass

Index: instruc.h
==================================================================
--- instruc.h
+++ instruc.h
@@ -288,100 +288,101 @@
 #define OP_BROADCASTCLASS 32902
 #define OP_BROADCASTEX 32903
 #define OP_BROADCASTEX_D 41095
 #define OP_BROADCASTSUM 32904
 #define OP_BROADCASTSUMEX 32905
-#define OP_CREATE 32906
-#define OP_CREATE_D 41098
-#define OP_DELINVENTORY 32907
-#define OP_DELTA 32908
-#define OP_DESTROY 32909
-#define OP_DESTROY_C 34957
-#define OP_DESTROY_D 41101
-#define OP_DESTROY_CD 43149
-#define OP_FLUSHCLASS 32910
-#define OP_FLUSHOBJ 32911
-#define OP_FLUSHOBJ_C 34959
-#define OP_GETINVENTORY 32912
-#define OP_HEIGHTAT 32913
-#define OP_IGNOREKEY 32914
-#define OP_INTMOVE 32915
-#define OP_INTMOVE_C 34963
-#define OP_INTMOVE_D 41107
-#define OP_INTMOVE_CD 43155
-#define OP_JUMPTO 32916
-#define OP_JUMPTO_C 34964
-#define OP_JUMPTO_D 41108
-#define OP_JUMPTO_CD 43156
-#define OP_LOC 32917
-#define OP_LOC_C 34965
-#define OP_LOCATEME 32918
-#define OP_LOSELEVEL 32919
-#define OP_MAXINVENTORY 32920
-#define OP_MOVE 32921
-#define OP_MOVE_C 34969
-#define OP_MOVE_D 41113
-#define OP_MOVE_CD 43161
-#define OP_MOVEPLUS 32922
-#define OP_MOVEPLUS_C 34970
-#define OP_MOVEPLUS_D 41114
-#define OP_MOVEPLUS_CD 43162
-#define OP_MOVETO 32923
-#define OP_MOVETO_C 34971
-#define OP_MOVETO_D 41115
-#define OP_MOVETO_CD 43163
-#define OP_NEWX 32924
-#define OP_NEWXY 32925
-#define OP_NEWY 32926
-#define OP_OBJABOVE 32927
-#define OP_OBJABOVE_C 34975
-#define OP_OBJBELOW 32928
-#define OP_OBJBELOW_C 34976
-#define OP_OBJBOTTOMAT 32929
-#define OP_OBJCLASSAT 32930
-#define OP_OBJDIR 32931
-#define OP_OBJDIR_C 34979
-#define OP_OBJLAYERAT 32932
-#define OP_OBJTOPAT 32933
-#define OP_POPUP 32934
-#define OP_POPUPARGS 32935
-#define OP_QUEUETURN 32936
-#define OP_SEND 32937
-#define OP_SEND_C 34985
-#define OP_SEND_D 41129
-#define OP_SEND_CD 43177
-#define OP_SENDEX 32938
-#define OP_SENDEX_C 34986
-#define OP_SENDEX_D 41130
-#define OP_SENDEX_CD 43178
-#define OP_SETINVENTORY 32939
-#define OP_SOUND 32940
-#define OP_SYNCHRONIZE 32941
-#define OP_TRACE 32942
-#define OP_VOLUMEAT 32943
-#define OP_WINLEVEL 32944
-#define OP_XDIR 32945
-#define OP_XDIR_C 34993
-#define OP_XYDIR 32946
-#define OP_YDIR 32947
-#define OP_YDIR_C 34995
-#define OP_MARK 32948
-#define OP_TMARK 32949
-#define OP_IN 32950
-#define OP_NIN 32951
-#define OP_MBEGIN 32952
-#define OP_ARRAY 32953
-#define OP_GETARRAY 32954
-#define OP_INITARRAY 32955
-#define OP_SETARRAY 32956
-#define OP_FUNCTION 32957
-#define OP_LOCAL 32958
-#define OP_LABEL 32959
-#define OP_STRING 32960
-#define OP_INT16 32961
-#define OP_INT32 32962
-#define OP_DISPATCH 32963
+#define OP_CHAIN 32906
+#define OP_CREATE 32907
+#define OP_CREATE_D 41099
+#define OP_DELINVENTORY 32908
+#define OP_DELTA 32909
+#define OP_DESTROY 32910
+#define OP_DESTROY_C 34958
+#define OP_DESTROY_D 41102
+#define OP_DESTROY_CD 43150
+#define OP_FLUSHCLASS 32911
+#define OP_FLUSHOBJ 32912
+#define OP_FLUSHOBJ_C 34960
+#define OP_GETINVENTORY 32913
+#define OP_HEIGHTAT 32914
+#define OP_IGNOREKEY 32915
+#define OP_INTMOVE 32916
+#define OP_INTMOVE_C 34964
+#define OP_INTMOVE_D 41108
+#define OP_INTMOVE_CD 43156
+#define OP_JUMPTO 32917
+#define OP_JUMPTO_C 34965
+#define OP_JUMPTO_D 41109
+#define OP_JUMPTO_CD 43157
+#define OP_LOC 32918
+#define OP_LOC_C 34966
+#define OP_LOCATEME 32919
+#define OP_LOSELEVEL 32920
+#define OP_MAXINVENTORY 32921
+#define OP_MOVE 32922
+#define OP_MOVE_C 34970
+#define OP_MOVE_D 41114
+#define OP_MOVE_CD 43162
+#define OP_MOVEPLUS 32923
+#define OP_MOVEPLUS_C 34971
+#define OP_MOVEPLUS_D 41115
+#define OP_MOVEPLUS_CD 43163
+#define OP_MOVETO 32924
+#define OP_MOVETO_C 34972
+#define OP_MOVETO_D 41116
+#define OP_MOVETO_CD 43164
+#define OP_NEWX 32925
+#define OP_NEWXY 32926
+#define OP_NEWY 32927
+#define OP_OBJABOVE 32928
+#define OP_OBJABOVE_C 34976
+#define OP_OBJBELOW 32929
+#define OP_OBJBELOW_C 34977
+#define OP_OBJBOTTOMAT 32930
+#define OP_OBJCLASSAT 32931
+#define OP_OBJDIR 32932
+#define OP_OBJDIR_C 34980
+#define OP_OBJLAYERAT 32933
+#define OP_OBJTOPAT 32934
+#define OP_POPUP 32935
+#define OP_POPUPARGS 32936
+#define OP_QUEUETURN 32937
+#define OP_SEND 32938
+#define OP_SEND_C 34986
+#define OP_SEND_D 41130
+#define OP_SEND_CD 43178
+#define OP_SENDEX 32939
+#define OP_SENDEX_C 34987
+#define OP_SENDEX_D 41131
+#define OP_SENDEX_CD 43179
+#define OP_SETINVENTORY 32940
+#define OP_SOUND 32941
+#define OP_SYNCHRONIZE 32942
+#define OP_TRACE 32943
+#define OP_VOLUMEAT 32944
+#define OP_WINLEVEL 32945
+#define OP_XDIR 32946
+#define OP_XDIR_C 34994
+#define OP_XYDIR 32947
+#define OP_YDIR 32948
+#define OP_YDIR_C 34996
+#define OP_MARK 32949
+#define OP_TMARK 32950
+#define OP_IN 32951
+#define OP_NIN 32952
+#define OP_MBEGIN 32953
+#define OP_ARRAY 32954
+#define OP_GETARRAY 32955
+#define OP_INITARRAY 32956
+#define OP_SETARRAY 32957
+#define OP_FUNCTION 32958
+#define OP_LOCAL 32959
+#define OP_LABEL 32960
+#define OP_STRING 32961
+#define OP_INT16 32962
+#define OP_INT32 32963
+#define OP_DISPATCH 32964
 #ifdef HEROMESH_CLASS
 static const Op_Names op_names[]={
 {"*",8486937},
 {"+",8421399},
 {"-",8421400},
@@ -392,11 +393,11 @@
 {"ARRIVED",8389124},
 {"Animate",8421507},
 {"Arg1",8552564},
 {"Arg2",8552565},
 {"Arg3",8552566},
-{"Array",8683705},
+{"Array",8683706},
 {"Arrivals",8618082},
 {"Arrived",8618080},
 {"Assassinate",8487044},
 {"B",9437196},
 {"BANG",8389380},
@@ -426,26 +427,26 @@
 {"CREATED",8389137},
 {"Class",8486966},
 {"Climb",9142346},
 {"CollisionLayers",8487024},
 {"Compatible",8487023},
-{"Create",10518666},
+{"Create",10518667},
 {"DEEP_POP",8389417},
 {"DEPARTED",8389125},
 {"DESTROY",8389122},
 {"DESTROYED",8389136},
 {"DINK",8389390},
 {"DOOR",8389378},
 {"DRLRLRINK",8389398},
 {"DYUPE",8389413},
 {"DefaultImage",8683647},
-{"DelInventory",8421515},
-{"Delta",8421516},
+{"DelInventory",8421516},
+{"Delta",8421517},
 {"Density",9142338},
 {"Departed",8618081},
 {"Departures",8618083},
-{"Destroy",10584205},
+{"Destroy",10584206},
 {"Destroyed",8487021},
 {"Dir",8618044},
 {"Distance",9142336},
 {"Done",8618092},
 {"E",9437184},
@@ -455,37 +456,37 @@
 {"FAROUT",8389421},
 {"FFFFTT",8389399},
 {"FLOATED",8389132},
 {"FROG",8389383},
 {"Finished",8552570},
-{"FlushClass",8421518},
-{"FlushObj",8487055},
+{"FlushClass",8421519},
+{"FlushObj",8487056},
 {"From",8421491},
 {"GLASS",8389379},
 {"GLISSANT",8389419},
-{"GetArray",8421562},
-{"GetInventory",8421520},
+{"GetArray",8421563},
+{"GetInventory",8421521},
 {"HAWK",8389425},
 {"HEARTBEAT",8389407},
 {"HIT",8389134},
 {"HITBY",8389135},
 {"Hard",8618062},
 {"Height",9142344},
-{"HeightAt",8421521},
+{"HeightAt",8421522},
 {"Help",8683648},
 {"INIT",8389120},
-{"IgnoreKey",8421522},
+{"IgnoreKey",8421523},
 {"Image",8618045},
 {"InPlace",8683646},
 {"Inertia",9142334},
-{"InitArray",8421563},
+{"InitArray",8421564},
 {"Input",8683644},
-{"IntMove",10584211},
+{"IntMove",10584212},
 {"Invisible",8618085},
 {"JAYAYAYNG",8389416},
 {"JUMPED",8389128},
-{"JumpTo",10584212},
+{"JumpTo",10584213},
 {"KEWEL",8389422},
 {"KEY",8389129},
 {"KLECK",8389387},
 {"KLINKK",8389385},
 {"Key",8421497},
@@ -495,53 +496,53 @@
 {"LB",9437195},
 {"LF",9437193},
 {"LOCK",8389408},
 {"LOOP",8388610},
 {"Level",8421496},
-{"Loc",8487061},
-{"LocateMe",8421526},
-{"LoseLevel",8421527},
+{"Loc",8487062},
+{"LocateMe",8421527},
+{"LoseLevel",8421528},
 {"MOVED",8389127},
 {"MOVING",8389130},
-{"MaxInventory",8421528},
+{"MaxInventory",8421529},
 {"Misc1",9142354},
 {"Misc2",9142356},
 {"Misc3",9142358},
 {"Misc4",9142360},
 {"Misc5",9142362},
 {"Misc6",9142364},
 {"Misc7",9142366},
-{"Move",10584217},
-{"Move+",10584218},
+{"Move",10584218},
+{"Move+",10584219},
 {"MoveNumber",8421495},
-{"MoveTo",10584219},
+{"MoveTo",10584220},
 {"Moved",8618091},
 {"Msg",8421490},
 {"N",9437186},
 {"NE",9437185},
 {"NW",9437187},
-{"NewX",8421532},
-{"NewXY",8421533},
-{"NewY",8421534},
+{"NewX",8421533},
+{"NewXY",8421534},
+{"NewY",8421535},
 {"OLDPHONE",8389402},
 {"ONCE",8388609},
 {"OSC",8388616},
 {"OSCLOOP",8388618},
-{"ObjAbove",8487071},
-{"ObjBelow",8487072},
-{"ObjBottomAt",8421537},
-{"ObjClassAt",8421538},
-{"ObjDir",8487075},
-{"ObjLayerAt",8421540},
-{"ObjTopAt",8421541},
+{"ObjAbove",8487072},
+{"ObjBelow",8487073},
+{"ObjBottomAt",8421538},
+{"ObjClassAt",8421539},
+{"ObjDir",8487076},
+{"ObjLayerAt",8421541},
+{"ObjTopAt",8421542},
 {"PLAYERMOVING",8389133},
 {"POSTINIT",8389138},
 {"POUR",8389377},
 {"POWER",8389386},
 {"Player",8487022},
-{"PopUp",8421542},
-{"QueueTurn",8421544},
+{"PopUp",8421543},
+{"QueueTurn",8421545},
 {"Quiz",8683645},
 {"R",9437198},
 {"RATCHET1",8389418},
 {"RATCHET2",8389412},
 {"RATTLE",8389403},
@@ -555,49 +556,49 @@
 {"STOP",8388608},
 {"SUBS",8683650},
 {"SUNK",8389131},
 {"SW",9437189},
 {"Self",8421489},
-{"Send",10584233},
-{"SendEx",10584234},
-{"SetArray",8421564},
-{"SetInventory",8421547},
+{"Send",10584234},
+{"SendEx",10584235},
+{"SetArray",8421565},
+{"SetInventory",8421548},
 {"Shape",8618041},
 {"ShapeDir",8618064},
 {"Sharp",8618063},
 {"Shovable",8618065},
-{"Sound",8421548},
+{"Sound",8421549},
 {"Stealthy",8618090},
 {"Strength",9142348},
-{"Synchronize",8421549},
+{"Synchronize",8421550},
 {"TAHTASHH",8389409},
 {"THMP_thmp",8389405},
 {"THWIT",8389384},
 {"TICK",8389391},
 {"Temperature",9142327},
-{"Trace",8421550},
+{"Trace",8421551},
 {"UH_OH",8389382},
 {"UNCORK",8389414},
 {"UNHH",8389381},
 {"UserSignal",8618087},
 {"UserState",8618088},
 {"VACUUM",8389411},
 {"VisualOnly",8618089},
 {"Volume",9142340},
-{"VolumeAt",8421551},
+{"VolumeAt",8421552},
 {"W",9437188},
 {"WAHOO",8389400},
 {"WHACK",8389423},
 {"Weight",9142342},
-{"WinLevel",8421552},
-{"XDir",8487089},
-{"XYDir",8421554},
+{"WinLevel",8421553},
+{"XDir",8487090},
+{"XYDir",8421555},
 {"Xloc",8486970},
-{"YDir",8487091},
+{"YDir",8487092},
 {"YEEHAW",8389401},
 {"Yloc",8486971},
-{"_",8421556},
+{"_",8421557},
 {"again",8683534},
 {"band",8421407},
 {"begin",8683533},
 {"bit",8683555},
 {"bit0",8388609},
@@ -634,36 +635,37 @@
 {"bit9",8423401},
 {"bnot",8421410},
 {"bor",8421408},
 {"bxor",8421409},
 {"c?",8421424},
+{"chain",8421514},
 {"cz?",8421425},
 {"dup",8421377},
 {"el",8683532},
 {"else",8683530},
 {"eq",8421416},
 {"for",8683538},
 {"ge",8486956},
 {"gt",8486954},
 {"if",8683529},
-{"in",8421558},
+{"in",8421559},
 {"is",8421422},
 {"land",8421412},
 {"le",8486957},
 {"lnot",8421415},
 {"lor",8421413},
 {"lsh",8421405},
 {"lt",8486955},
 {"lxor",8421414},
 {"m?",8421426},
-{"mbegin",8683704},
+{"mbegin",8683705},
 {"mod",8486939},
 {"n?",8421423},
 {"ne",8421417},
 {"neg",8421404},
 {"next",8683539},
-{"nin",8421559},
+{"nin",8421560},
 {"nip",8421379},
 {"o?",8421428},
 {"over",8421384},
 {"oz?",8421429},
 {"pick",8421383},
@@ -672,12 +674,12 @@
 {"rot",8421381},
 {"rsh",8486942},
 {"s?",8421427},
 {"swap",8421378},
 {"then",8683531},
-{"tmark",8421557},
+{"tmark",8421558},
 {"tuck",8421380},
 {"until",8683535},
 {"while",8683536},
 };
-#define N_OP_NAMES 296
+#define N_OP_NAMES 297
 #endif