no more nil-in-table

16 files changed, 23 insertions, 172 deletions

diff --git a/lapi.c b/lapi.c
index eb872df8..877fb2ac 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.289 2018/02/27 17:48:28 roberto Exp roberto $
+** $Id: lapi.c,v 2.290 2018/02/27 20:01:55 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -705,27 +705,6 @@ LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) {
 }
 
 
-static int auxkeydef (lua_State *L, int idx, int remove) {
-  int res;
-  lua_lock(L);
-  api_checknelems(L, 1);
-  res = luaT_keydef(L, index2value(L, idx), s2v(L->top - 1), remove);
-  L->top--;  /* remove key */
-  lua_unlock(L);
-  return res;
-}
-
-
-LUA_API void lua_removekey (lua_State *L, int idx) {
-  auxkeydef(L, idx, 1);
-}
-
-
-LUA_API int lua_keyin (lua_State *L, int idx) {
-  return auxkeydef(L, idx, 0);
-}
-
-
 LUA_API void lua_createtable (lua_State *L, int narray, int nrec) {
   Table *t;
   lua_lock(L);
diff --git a/lcode.c b/lcode.c
index 661c7916..ab91561c 100644
--- a/lcode.c
+++ b/lcode.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.c,v 2.159 2018/03/07 15:55:38 roberto Exp roberto $
+** $Id: lcode.c,v 2.160 2018/03/16 14:22:09 roberto Exp roberto $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -678,10 +678,6 @@ void luaK_dischargevars (FuncState *fs, expdesc *e) {
       e->k = VNONRELOC;  /* becomes a non-relocatable value */
       break;
     }
-    case VUNDEF: {  /* not a real expression */
-      luaK_semerror(fs->ls, "'undef' is not a value!!");
-      break;
-    }
     case VUPVAL: {  /* move value to some (pending) register */
       e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0);
       e->k = VRELOC;
@@ -1410,48 +1406,6 @@ static void codeeq (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) {
 }
 
 
-static void normalizeindexed (FuncState *fs, expdesc *v) {
-  if (v->k != VINDEXED) {  /* not in proper form? */
-    int key = fs->freereg;  /* register with key value */
-    luaK_reserveregs(fs, 1);
-    switch (v->k) {
-      case VINDEXI:
-        luaK_int(fs, key, v->u.ind.idx);
-        break;
-      case VINDEXSTR:
-        luaK_codek(fs, key, v->u.ind.idx);
-        break;
-      case VINDEXUP:
-        luaK_codek(fs, key, v->u.ind.idx);
-        luaK_codeABC(fs, OP_GETUPVAL, fs->freereg, v->u.ind.t, 0);
-        v->u.ind.t = fs->freereg;
-        luaK_reserveregs(fs, 1);  /* one more register for the upvalue */
-        break;
-      default:
-        luaK_semerror(fs->ls, "'undef' is not a value!!");
-        break;
-    }
-    v->u.ind.idx = key;
-    v->k = VINDEXED;
-  }
-  freeregs(fs, v->u.ind.t, v->u.ind.idx);
-}
-
-
-static void codeisdef (FuncState *fs, int eq, expdesc *v) {
-  normalizeindexed(fs, v);
-  v->u.info = luaK_codeABCk(fs, OP_ISDEF, 0, v->u.ind.t, v->u.ind.idx, eq);
-  v->k = VRELOC;
-}
-
-
-void luaK_codeundef (FuncState *fs, expdesc *v) {
-  normalizeindexed(fs, v);
-  v->u.info = luaK_codeABC(fs, OP_UNDEF, v->u.ind.t, v->u.ind.idx, 0);
-  v->k = VRELOC;
-}
-
-
 /*
 ** Apply prefix operation 'op' to expression 'e'.
 */
@@ -1500,7 +1454,7 @@ void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
       break;
     }
     case OPR_EQ: case OPR_NE: {
-      if (!tonumeral(v, NULL) && fs->ls->t.token != TK_UNDEF)
+      if (!tonumeral(v, NULL))
         luaK_exp2RK(fs, v);
       /* else keep numeral, which may be an immediate operand */
       break;
@@ -1597,10 +1551,7 @@ void luaK_posfix (FuncState *fs, BinOpr opr,
       break;
     }
     case OPR_EQ: case OPR_NE: {
-      if (e2->k == VUNDEF)
-        codeisdef(fs, opr == OPR_NE, e1);
-      else
-        codeeq(fs, opr, e1, e2);
+      codeeq(fs, opr, e1, e2);
       break;
     }
     case OPR_LT: case OPR_LE: {
diff --git a/lcode.h b/lcode.h
index 6ec8b099..0c415973 100644
--- a/lcode.h
+++ b/lcode.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lcode.h,v 1.71 2018/03/07 15:55:38 roberto Exp roberto $
+** $Id: lcode.h,v 1.72 2018/03/19 20:03:44 roberto Exp roberto $
 ** Code generator for Lua
 ** See Copyright Notice in lua.h
 */
@@ -90,7 +90,6 @@ LUAI_FUNC void luaK_posfix (FuncState *fs, BinOpr op, expdesc *v1,
                             expdesc *v2, int line);
 LUAI_FUNC void luaK_setlist (FuncState *fs, int base, int nelems, int tostore);
 LUAI_FUNC void luaK_finish (FuncState *fs);
-LUAI_FUNC void luaK_codeundef (FuncState *fs, expdesc *e);
 LUAI_FUNC l_noret luaK_semerror (LexState *ls, const char *msg);
 
 
diff --git a/ljumptab.h b/ljumptab.h
index 373d541c..c642c23e 100644
--- a/ljumptab.h
+++ b/ljumptab.h
@@ -79,8 +79,6 @@ static void *disptab[] = {
 &&L_OP_GEI,
 &&L_OP_TEST,
 &&L_OP_TESTSET,
-&&L_OP_UNDEF,
-&&L_OP_ISDEF,
 &&L_OP_CALL,
 &&L_OP_TAILCALL,
 &&L_OP_RETURN,
diff --git a/llex.c b/llex.c
index 7e59eb49..9419a8cd 100644
--- a/llex.c
+++ b/llex.c
@@ -1,5 +1,5 @@
 /*
-** $Id: llex.c,v 2.100 2018/02/23 13:13:31 roberto Exp roberto $
+** $Id: llex.c,v 2.101 2018/03/07 15:55:38 roberto Exp roberto $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -41,7 +41,7 @@ static const char *const luaX_tokens [] = {
     "and", "break", "do", "else", "elseif",
     "end", "false", "for", "function", "goto", "if",
     "in", "local", "nil", "not", "or", "repeat",
-    "return", "then", "true", "undef", "until", "while",
+    "return", "then", "true", "until", "while",
     "//", "..", "...", "==", ">=", "<=", "~=",
     "<<", ">>", "::", "<eof>",
     "<number>", "<integer>", "<name>", "<string>"
diff --git a/llex.h b/llex.h
index fb33c33f..d1d5a4a8 100644
--- a/llex.h
+++ b/llex.h
@@ -1,5 +1,5 @@
 /*
-** $Id: llex.h,v 1.80 2018/01/28 15:13:26 roberto Exp roberto $
+** $Id: llex.h,v 1.81 2018/03/07 15:55:38 roberto Exp roberto $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -28,7 +28,7 @@ enum RESERVED {
   TK_AND = FIRST_RESERVED, TK_BREAK,
   TK_DO, TK_ELSE, TK_ELSEIF, TK_END, TK_FALSE, TK_FOR, TK_FUNCTION,
   TK_GOTO, TK_IF, TK_IN, TK_LOCAL, TK_NIL, TK_NOT, TK_OR, TK_REPEAT,
-  TK_RETURN, TK_THEN, TK_TRUE, TK_UNDEF, TK_UNTIL, TK_WHILE,
+  TK_RETURN, TK_THEN, TK_TRUE, TK_UNTIL, TK_WHILE,
   /* other terminal symbols */
   TK_IDIV, TK_CONCAT, TK_DOTS, TK_EQ, TK_GE, TK_LE, TK_NE,
   TK_SHL, TK_SHR,
diff --git a/lobject.h b/lobject.h
index b18dce47..dc5f32a1 100644
--- a/lobject.h
+++ b/lobject.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.h,v 2.140 2018/02/26 13:35:03 roberto Exp roberto $
+** $Id: lobject.h,v 2.141 2018/02/26 14:16:05 roberto Exp roberto $
 ** Type definitions for Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -160,15 +160,9 @@ typedef StackValue *StkId;  /* index to stack elements */
 #define isreallyempty(v)        checktag((v), LUA_TEMPTY)
 
 
-#if defined(LUA_NILINTABLE)
-
-#define isempty(v)              isreallyempty(v)
-
-#else /* By default, entries with any kind of nil are considered empty */
-
+/* By default, entries with any kind of nil are considered empty */
 #define isempty(v)              ttisnilorempty(v)
 
-#endif
 
 /* macro defining an empty value */
 #define EMPTYCONSTANT   {NULL}, LUA_TEMPTY
diff --git a/lopcodes.c b/lopcodes.c
index ac59537b..3db9db25 100644
--- a/lopcodes.c
+++ b/lopcodes.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lopcodes.c,v 1.79 2018/02/21 15:49:32 roberto Exp roberto $
+** $Id: lopcodes.c,v 1.80 2018/03/07 15:55:38 roberto Exp roberto $
 ** Opcodes for Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -79,8 +79,6 @@ LUAI_DDEF const char *const luaP_opnames[NUM_OPCODES+1] = {
   "GEI",
   "TEST",
   "TESTSET",
-  "UNDEF",
-  "ISDEF",
   "CALL",
   "TAILCALL",
   "RETURN",
@@ -164,8 +162,6 @@ LUAI_DDEF const lu_byte luaP_opmodes[NUM_OPCODES] = {
  ,opmode(0, 0, 1, 0, iABC)              /* OP_GEI */
  ,opmode(0, 0, 1, 0, iABC)              /* OP_TEST */
  ,opmode(0, 0, 1, 1, iABC)              /* OP_TESTSET */
- ,opmode(0, 0, 0, 0, iABC)              /* OP_UNDEF */
- ,opmode(0, 0, 0, 1, iABC)              /* OP_ISDEF */
  ,opmode(1, 1, 0, 1, iABC)              /* OP_CALL */
  ,opmode(1, 1, 0, 1, iABC)              /* OP_TAILCALL */
  ,opmode(0, 1, 0, 0, iABC)              /* OP_RETURN */
diff --git a/lopcodes.h b/lopcodes.h
index ddbaf8da..b9e9ec96 100644
--- a/lopcodes.h
+++ b/lopcodes.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lopcodes.h,v 1.189 2018/02/21 15:49:32 roberto Exp roberto $
+** $Id: lopcodes.h,v 1.190 2018/03/07 15:55:38 roberto Exp roberto $
 ** Opcodes for Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -266,9 +266,6 @@ OP_GEI,/*	A sB	if ((R(A) >= sB) ~= k) then pc++		*/
 OP_TEST,/*      A       if (not R(A) == k) then pc++                    */
 OP_TESTSET,/*   A B     if (not R(B) == k) then R(A) := R(B) else pc++  */
 
-OP_UNDEF,/*     A B     R(A)[R(B)] = undef                              */
-OP_ISDEF,/*     A B C   R(A) = (R(B)[R(C)] == undef                     */
-
 OP_CALL,/*      A B C   R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */
 OP_TAILCALL,/*  A B C   return R(A)(R(A+1), ... ,R(A+B-1))              */
 
diff --git a/lparser.c b/lparser.c
index 9bf5485e..e67d70ea 100644
--- a/lparser.c
+++ b/lparser.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lparser.c,v 2.178 2018/02/17 19:20:00 roberto Exp roberto $
+** $Id: lparser.c,v 2.179 2018/03/07 15:55:38 roberto Exp roberto $
 ** Lua Parser
 ** See Copyright Notice in lua.h
 */
@@ -893,11 +893,6 @@ static void primaryexp (LexState *ls, expdesc *v) {
       singlevar(ls, v);
       return;
     }
-    case TK_UNDEF: {
-      luaX_next(ls);
-      init_exp(v, VUNDEF, 0);
-      return;
-    }
     default: {
       luaX_syntaxerror(ls, "unexpected symbol");
     }
@@ -1183,10 +1178,6 @@ static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
   else {  /* assignment -> '=' explist */
     int nexps;
     checknext(ls, '=');
-    if (nvars == 1 && testnext(ls, TK_UNDEF)) {
-      luaK_codeundef(ls->fs, &lh->v);
-      return;
-    }
     nexps = explist(ls, &e);
     if (nexps != nvars)
       adjust_assign(ls, nvars, nexps, &e);
@@ -1652,11 +1643,6 @@ static void statement (LexState *ls) {
       luaX_next(ls);  /* skip LOCAL */
       if (testnext(ls, TK_FUNCTION))  /* local function? */
         localfunc(ls);
-      else if (testnext(ls, TK_UNDEF))
-        (void)0;  /* ignore */
-      /* old versions may need to declare 'local undef'
-         when using 'undef' with no environment; so this
-         version accepts (and ignores) these declarations */
       else
         localstat(ls);
       break;
diff --git a/lparser.h b/lparser.h
index b8705e84..da6a7483 100644
--- a/lparser.h
+++ b/lparser.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lparser.h,v 1.80 2017/12/14 14:24:02 roberto Exp roberto $
+** $Id: lparser.h,v 1.81 2018/03/07 15:55:38 roberto Exp roberto $
 ** Lua Parser
 ** See Copyright Notice in lua.h
 */
@@ -52,8 +52,7 @@ typedef enum {
   VRELOC,  /* expression can put result in any register;
               info = instruction pc */
   VCALL,  /* expression is a function call; info = instruction pc */
-  VVARARG,  /* vararg expression; info = instruction pc */
-  VUNDEF  /* the 'undef' "expression" */
+  VVARARG  /* vararg expression; info = instruction pc */
 } expkind;
 
 
diff --git a/ltablib.c b/ltablib.c
index 5a78c15b..7bbc3a07 100644
--- a/ltablib.c
+++ b/ltablib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltablib.c,v 1.95 2018/02/27 18:47:32 roberto Exp roberto $
+** $Id: ltablib.c,v 1.96 2018/03/16 14:18:18 roberto Exp roberto $
 ** Library for Table Manipulation
 ** See Copyright Notice in lua.h
 */
@@ -95,8 +95,8 @@ static int tremove (lua_State *L) {
     lua_geti(L, 1, pos + 1);
     lua_seti(L, 1, pos);  /* t[pos] = t[pos + 1] */
   }
-  lua_pushinteger(L, pos);
-  lua_removekey(L, 1);  /* remove entry t[pos] */
+  lua_pushnil(L);
+  lua_seti(L, 1, pos);  /* remove entry t[pos] */
   return 1;
 }
 
diff --git a/ltm.c b/ltm.c
index 2a9a4cbe..6d285510 100644
--- a/ltm.c
+++ b/ltm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.c,v 2.65 2018/02/26 14:16:05 roberto Exp roberto $
+** $Id: ltm.c,v 2.66 2018/02/27 17:48:28 roberto Exp roberto $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -38,7 +38,6 @@ LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTAGS] = {
 void luaT_init (lua_State *L) {
   static const char *const luaT_eventname[] = {  /* ORDER TM */
     "__index", "__newindex",
-    "__undef", "__isdef",
     "__gc", "__mode", "__len", "__eq",
     "__add", "__sub", "__mul", "__mod", "__pow",
     "__div", "__idiv",
@@ -250,30 +249,3 @@ void luaT_getvarargs (lua_State *L, CallInfo *ci, StkId where, int wanted) {
     setnilvalue(s2v(where + i));
 }
 
-
-int luaT_keydef (lua_State *L, TValue *obj, TValue *key, int remove) {
-  const TValue *tm;
-  TMS event = remove ? TM_UNDEF : TM_ISDEF;
-  if (!ttistable(obj)) {  /* not a table? */
-    tm = luaT_gettmbyobj(L, obj, event);  /* get its metamethod */
-    if (notm(tm)) {  /* no metamethod? */
-      const char *msg = remove ? "remove key from" : "check key from";
-      luaG_typeerror(L, obj, msg);  /* error */
-    }
-    /* else will call metamethod 'tm' */
-  }
-  else {  /* 'obj' is a table */
-    Table *t = hvalue(obj);
-    tm = fasttm(L, t->metatable, event);
-    if (tm == NULL) {  /* no metamethod? */
-      const TValue *val = luaH_get(t, key);  /* get entry */
-      int res = !isempty(val);  /* true if entry is not empty */
-      if (remove && res)  /* key is present and should be removed? */
-        setempty(cast(TValue*, val));  /* remove it */
-      return res;
-    }
-    /* else will call metamethod 'tm' */
-  }
-  luaT_callTMres(L, tm, obj, key, L->top);
-  return !l_isfalse(s2v(L->top));
-}
diff --git a/ltm.h b/ltm.h
index 6e961d27..7eb60b4c 100644
--- a/ltm.h
+++ b/ltm.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.h,v 2.33 2018/02/23 13:13:31 roberto Exp roberto $
+** $Id: ltm.h,v 2.34 2018/02/27 17:48:28 roberto Exp roberto $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -19,8 +19,6 @@
 typedef enum {
   TM_INDEX,
   TM_NEWINDEX,
-  TM_UNDEF,
-  TM_ISDEF,
   TM_GC,
   TM_MODE,
   TM_LEN,
@@ -91,7 +89,5 @@ LUAI_FUNC void luaT_adjustvarargs (lua_State *L, int nfixparams,
 LUAI_FUNC void luaT_getvarargs (lua_State *L, struct CallInfo *ci,
                                               StkId where, int wanted);
 
-LUAI_FUNC int luaT_keydef (lua_State *L, TValue *obj, TValue *key, int remove);
-
 
 #endif
diff --git a/lua.h b/lua.h
index 31e20397..3f76fbea 100644
--- a/lua.h
+++ b/lua.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lua.h,v 1.344 2018/03/05 14:15:32 roberto Exp roberto $
+** $Id: lua.h,v 1.345 2018/03/16 15:33:34 roberto Exp roberto $
 ** Lua - A Scripting Language
 ** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
 ** See Copyright Notice at the end of this file
@@ -331,9 +331,6 @@ LUA_API size_t   (lua_stringtonumber) (lua_State *L, const char *s);
 LUA_API lua_Alloc (lua_getallocf) (lua_State *L, void **ud);
 LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 
-LUA_API void (lua_removekey) (lua_State *L, int idx);
-LUA_API int (lua_keyin) (lua_State *L, int idx);
-
 
 /*
 ** {==============================================================
diff --git a/lvm.c b/lvm.c
index 5e3c2ca0..9e044aae 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.351 2018/03/16 14:21:20 roberto Exp roberto $
+** $Id: lvm.c,v 2.352 2018/04/02 17:52:07 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -1560,19 +1560,6 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
         }
         vmbreak;
       }
-      vmcase(OP_UNDEF) {
-        TValue *rb = vRB(i);
-        luaT_keydef(L, vra, rb, 1);
-        vmbreak;
-      }
-      vmcase(OP_ISDEF) {
-        TValue *rb = vRB(i);
-        TValue *rc = vRC(i);
-        int res;
-        Protect(res = luaT_keydef(L, rb, rc, 0));
-        setbvalue(vra, res == GETARG_k(i));
-        vmbreak;
-      }
       vmcase(OP_CALL) {
         int b = GETARG_B(i);
         int nresults = GETARG_C(i) - 1;