lvm.h File Reference

#include "ldo.h"
#include "lobject.h"
#include "ltm.h"

Go to the source code of this file.

Macros
#define	tostring(L, o)   ((ttype(o) == LUA_TSTRING) || (luaV_tostring(L, o)))
#define	tonumber(o, n)
#define	equalobj(L, o1, o2)    (ttype(o1) == ttype(o2) && luaV_equalval(L, o1, o2))

Functions
LUAI_FUNC int	luaV_lessthan (lua_State *L, const TValue *l, const TValue *r)
LUAI_FUNC int	luaV_equalval (lua_State *L, const TValue *t1, const TValue *t2)
LUAI_FUNC const TValue *	luaV_tonumber (const TValue *obj, TValue *n)
LUAI_FUNC int	luaV_tostring (lua_State *L, StkId obj)
LUAI_FUNC void	luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val)
LUAI_FUNC void	luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val)
LUAI_FUNC void	luaV_execute (lua_State *L, int nexeccalls)
LUAI_FUNC void	luaV_concat (lua_State *L, int total, int last)

Macro Definition Documentation

equalobj

#define equalobj	(		L,
			o1,
			o2 )    (ttype(o1) == ttype(o2) && luaV_equalval(L, o1, o2))

Definition at line 21 of file lua-5.1.5/src/lvm.h.

#define equalobj(L,o1,o2) \
    (ttype(o1) == ttype(o2) && luaV_equalval(L, o1, o2))

Referenced by lua_compare(), lua_equal(), luaV_execute(), and luaV_execute().

tonumber

#define tonumber	(		o,
			n )

Value:

                         (ttype(o) == LUA_TNUMBER || \
                         (((o) = luaV_tonumber(o,n)) != NULL))

Definition at line 18 of file lua-5.1.5/src/lvm.h.

#define tonumber(o,n)   (ttype(o) == LUA_TNUMBER || \
                         (((o) = luaV_tonumber(o,n)) != NULL))

Referenced by forlimit(), forlimit(), forprep(), lua_isnumber(), lua_tointeger(), lua_tointegerx(), lua_tonumber(), lua_tonumberx(), lua_tonumberx(), lua_tounsignedx(), luaG_opinterror(), luaO_arith(), luaT_trybinTM(), luaV_execute(), and luaV_execute().

tostring

#define tostring	(		L,
			o )   ((ttype(o) == LUA_TSTRING) || (luaV_tostring(L, o)))

Definition at line 16 of file lua-5.1.5/src/lvm.h.

Referenced by luaV_concat(), and luaV_concat().

Function Documentation

luaV_concat()

LUAI_FUNC void luaV_concat	(	lua_State *	L,
		int	total,
		int	last )

Definition at line 282 of file lua-5.1.5/src/lvm.c.

                                                     {
  do {
    StkId top = L->base + last + 1;
    int n = 2;  /* number of elements handled in this pass (at least 2) */
    if (!(ttisstring(top-2) || ttisnumber(top-2)) || !tostring(L, top-1)) {
      if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
        luaG_concaterror(L, top-2, top-1);
    } else if (tsvalue(top-1)->len == 0)  /* second op is empty? */
      (void)tostring(L, top - 2);  /* result is first op (as string) */
    else {
      /* at least two string values; get as many as possible */
      size_t tl = tsvalue(top-1)->len;
      char *buffer;
      int i;
      /* collect total length */
      for (n = 1; n < total && tostring(L, top-n-1); n++) {
        size_t l = tsvalue(top-n-1)->len;
        if (l >= MAX_SIZET - tl) luaG_runerror(L, "string length overflow");
        tl += l;
      }
      buffer = luaZ_openspace(L, &G(L)->buff, tl);
      tl = 0;
      for (i=n; i>0; i--) {  /* concat all strings */
        size_t l = tsvalue(top-i)->len;
        memcpy(buffer+tl, svalue(top-i), l);
        tl += l;
      }
      setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl));
    }
    total -= n-1;  /* got `n' strings to create 1 new */
    last -= n-1;
  } while (total > 1);  /* repeat until only 1 result left */
}

References lua_State::base, call_binTM(), G, luaG_concaterror(), luaG_runerror(), luaS_newlstr(), luaZ_openspace(), MAX_SIZET, setsvalue2s, svalue, TM_CONCAT, tostring, tsvalue, ttisnumber, and ttisstring.

Referenced by lua_concat(), luaO_pushvfstring(), luaV_execute(), and pushstr().

luaV_equalval()

LUAI_FUNC int luaV_equalval	(	lua_State *	L,
		const TValue *	t1,
		const TValue *	t2 )

Definition at line 255 of file lua-5.1.5/src/lvm.c.

                                                                     {
  const TValue *tm;
  lua_assert(ttype(t1) == ttype(t2));
  switch (ttype(t1)) {
    case LUA_TNIL: return 1;
    case LUA_TNUMBER: return luai_numeq(nvalue(t1), nvalue(t2));
    case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2);  /* true must be 1 !! */
    case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
    case LUA_TUSERDATA: {
      if (uvalue(t1) == uvalue(t2)) return 1;
      tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable,
                         TM_EQ);
      break;  /* will try TM */
    }
    case LUA_TTABLE: {
      if (hvalue(t1) == hvalue(t2)) return 1;
      tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
      break;  /* will try TM */
    }
    default: return gcvalue(t1) == gcvalue(t2);
  }
  if (tm == NULL) return 0;  /* no TM? */
  callTMres(L, L->top, tm, t1, t2);  /* call TM */
  return !l_isfalse(L->top);
}

References bvalue, callTMres(), gcvalue, get_compTM(), hvalue, l_isfalse, lua_assert, LUA_TBOOLEAN, LUA_TLIGHTUSERDATA, LUA_TNIL, LUA_TNUMBER, LUA_TTABLE, LUA_TUSERDATA, luai_numeq, NULL, nvalue, pvalue, TM_EQ, lua_State::top, ttype, and uvalue.

luaV_execute()

LUAI_FUNC void luaV_execute	(	lua_State *	L,
		int	nexeccalls )

Definition at line 377 of file lua-5.1.5/src/lvm.c.

                                                 {
  LClosure *cl;
  StkId base;
  TValue *k;
  const Instruction *pc;
 reentry:  /* entry point */
  lua_assert(isLua(L->ci));
  pc = L->savedpc;
  cl = &clvalue(L->ci->func)->l;
  base = L->base;
  k = cl->p->k;
  /* main loop of interpreter */
  for (;;) {
    const Instruction i = *pc++;
    StkId ra;
    if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
        (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
      traceexec(L, pc);
      if (L->status == LUA_YIELD) {  /* did hook yield? */
        L->savedpc = pc - 1;
        return;
      }
      base = L->base;
    }
    /* warning!! several calls may realloc the stack and invalidate `ra' */
    ra = RA(i);
    lua_assert(base == L->base && L->base == L->ci->base);
    lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
    lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
    switch (GET_OPCODE(i)) {
      case OP_MOVE: {
        setobjs2s(L, ra, RB(i));
        continue;
      }
      case OP_LOADK: {
        setobj2s(L, ra, KBx(i));
        continue;
      }
      case OP_LOADBOOL: {
        setbvalue(ra, GETARG_B(i));
        if (GETARG_C(i)) pc++;  /* skip next instruction (if C) */
        continue;
      }
      case OP_LOADNIL: {
        TValue *rb = RB(i);
        do {
          setnilvalue(rb--);
        } while (rb >= ra);
        continue;
      }
      case OP_GETUPVAL: {
        int b = GETARG_B(i);
        setobj2s(L, ra, cl->upvals[b]->v);
        continue;
      }
      case OP_GETGLOBAL: {
        TValue g;
        TValue *rb = KBx(i);
        sethvalue(L, &g, cl->env);
        lua_assert(ttisstring(rb));
        Protect(luaV_gettable(L, &g, rb, ra));
        continue;
      }
      case OP_GETTABLE: {
        Protect(luaV_gettable(L, RB(i), RKC(i), ra));
        continue;
      }
      case OP_SETGLOBAL: {
        TValue g;
        sethvalue(L, &g, cl->env);
        lua_assert(ttisstring(KBx(i)));
        Protect(luaV_settable(L, &g, KBx(i), ra));
        continue;
      }
      case OP_SETUPVAL: {
        UpVal *uv = cl->upvals[GETARG_B(i)];
        setobj(L, uv->v, ra);
        luaC_barrier(L, uv, ra);
        continue;
      }
      case OP_SETTABLE: {
        Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
        continue;
      }
      case OP_NEWTABLE: {
        int b = GETARG_B(i);
        int c = GETARG_C(i);
        sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
        Protect(luaC_checkGC(L));
        continue;
      }
      case OP_SELF: {
        StkId rb = RB(i);
        setobjs2s(L, ra+1, rb);
        Protect(luaV_gettable(L, rb, RKC(i), ra));
        continue;
      }
      case OP_ADD: {
        arith_op(luai_numadd, TM_ADD);
        continue;
      }
      case OP_SUB: {
        arith_op(luai_numsub, TM_SUB);
        continue;
      }
      case OP_MUL: {
        arith_op(luai_nummul, TM_MUL);
        continue;
      }
      case OP_DIV: {
        arith_op(luai_numdiv, TM_DIV);
        continue;
      }
      case OP_MOD: {
        arith_op(luai_nummod, TM_MOD);
        continue;
      }
      case OP_POW: {
        arith_op(luai_numpow, TM_POW);
        continue;
      }
      case OP_UNM: {
        TValue *rb = RB(i);
        if (ttisnumber(rb)) {
          lua_Number nb = nvalue(rb);
          setnvalue(ra, luai_numunm(nb));
        }
        else {
          Protect(Arith(L, ra, rb, rb, TM_UNM));
        }
        continue;
      }
      case OP_NOT: {
        int res = l_isfalse(RB(i));  /* next assignment may change this value */
        setbvalue(ra, res);
        continue;
      }
      case OP_LEN: {
        const TValue *rb = RB(i);
        switch (ttype(rb)) {
          case LUA_TTABLE: {
            setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
            break;
          }
          case LUA_TSTRING: {
            setnvalue(ra, cast_num(tsvalue(rb)->len));
            break;
          }
          default: {  /* try metamethod */
            Protect(
              if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
                luaG_typeerror(L, rb, "get length of");
            )
          }
        }
        continue;
      }
      case OP_CONCAT: {
        int b = GETARG_B(i);
        int c = GETARG_C(i);
        Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
        setobjs2s(L, RA(i), base+b);
        continue;
      }
      case OP_JMP: {
        dojump(L, pc, GETARG_sBx(i));
        continue;
      }
      case OP_EQ: {
        TValue *rb = RKB(i);
        TValue *rc = RKC(i);
        Protect(
          if (equalobj(L, rb, rc) == GETARG_A(i))
            dojump(L, pc, GETARG_sBx(*pc));
        )
        pc++;
        continue;
      }
      case OP_LT: {
        Protect(
          if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
            dojump(L, pc, GETARG_sBx(*pc));
        )
        pc++;
        continue;
      }
      case OP_LE: {
        Protect(
          if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
            dojump(L, pc, GETARG_sBx(*pc));
        )
        pc++;
        continue;
      }
      case OP_TEST: {
        if (l_isfalse(ra) != GETARG_C(i))
          dojump(L, pc, GETARG_sBx(*pc));
        pc++;
        continue;
      }
      case OP_TESTSET: {
        TValue *rb = RB(i);
        if (l_isfalse(rb) != GETARG_C(i)) {
          setobjs2s(L, ra, rb);
          dojump(L, pc, GETARG_sBx(*pc));
        }
        pc++;
        continue;
      }
      case OP_CALL: {
        int b = GETARG_B(i);
        int nresults = GETARG_C(i) - 1;
        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
        L->savedpc = pc;
        switch (luaD_precall(L, ra, nresults)) {
          case PCRLUA: {
            nexeccalls++;
            goto reentry;  /* restart luaV_execute over new Lua function */
          }
          case PCRC: {
            /* it was a C function (`precall' called it); adjust results */
            if (nresults >= 0) L->top = L->ci->top;
            base = L->base;
            continue;
          }
          default: {
            return;  /* yield */
          }
        }
      }
      case OP_TAILCALL: {
        int b = GETARG_B(i);
        if (b != 0) L->top = ra+b;  /* else previous instruction set top */
        L->savedpc = pc;
        lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
        switch (luaD_precall(L, ra, LUA_MULTRET)) {
          case PCRLUA: {
            /* tail call: put new frame in place of previous one */
            CallInfo *ci = L->ci - 1;  /* previous frame */
            int aux;
            StkId func = ci->func;
            StkId pfunc = (ci+1)->func;  /* previous function index */
            if (L->openupval) luaF_close(L, ci->base);
            L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
            for (aux = 0; pfunc+aux < L->top; aux++)  /* move frame down */
              setobjs2s(L, func+aux, pfunc+aux);
            ci->top = L->top = func+aux;  /* correct top */
            lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
            ci->savedpc = L->savedpc;
            ci->tailcalls++;  /* one more call lost */
            L->ci--;  /* remove new frame */
            goto reentry;
          }
          case PCRC: {  /* it was a C function (`precall' called it) */
            base = L->base;
            continue;
          }
          default: {
            return;  /* yield */
          }
        }
      }
      case OP_RETURN: {
        int b = GETARG_B(i);
        if (b != 0) L->top = ra+b-1;
        if (L->openupval) luaF_close(L, base);
        L->savedpc = pc;
        b = luaD_poscall(L, ra);
        if (--nexeccalls == 0)  /* was previous function running `here'? */
          return;  /* no: return */
        else {  /* yes: continue its execution */
          if (b) L->top = L->ci->top;
          lua_assert(isLua(L->ci));
          lua_assert(GET_OPCODE(*((L->ci)->savedpc - 1)) == OP_CALL);
          goto reentry;
        }
      }
      case OP_FORLOOP: {
        lua_Number step = nvalue(ra+2);
        lua_Number idx = luai_numadd(nvalue(ra), step); /* increment index */
        lua_Number limit = nvalue(ra+1);
        if (luai_numlt(0, step) ? luai_numle(idx, limit)
                                : luai_numle(limit, idx)) {
          dojump(L, pc, GETARG_sBx(i));  /* jump back */
          setnvalue(ra, idx);  /* update internal index... */
          setnvalue(ra+3, idx);  /* ...and external index */
        }
        continue;
      }
      case OP_FORPREP: {
        const TValue *init = ra;
        const TValue *plimit = ra+1;
        const TValue *pstep = ra+2;
        L->savedpc = pc;  /* next steps may throw errors */
        if (!tonumber(init, ra))
          luaG_runerror(L, LUA_QL("for") " initial value must be a number");
        else if (!tonumber(plimit, ra+1))
          luaG_runerror(L, LUA_QL("for") " limit must be a number");
        else if (!tonumber(pstep, ra+2))
          luaG_runerror(L, LUA_QL("for") " step must be a number");
        setnvalue(ra, luai_numsub(nvalue(ra), nvalue(pstep)));
        dojump(L, pc, GETARG_sBx(i));
        continue;
      }
      case OP_TFORLOOP: {
        StkId cb = ra + 3;  /* call base */
        setobjs2s(L, cb+2, ra+2);
        setobjs2s(L, cb+1, ra+1);
        setobjs2s(L, cb, ra);
        L->top = cb+3;  /* func. + 2 args (state and index) */
        Protect(luaD_call(L, cb, GETARG_C(i)));
        L->top = L->ci->top;
        cb = RA(i) + 3;  /* previous call may change the stack */
        if (!ttisnil(cb)) {  /* continue loop? */
          setobjs2s(L, cb-1, cb);  /* save control variable */
          dojump(L, pc, GETARG_sBx(*pc));  /* jump back */
        }
        pc++;
        continue;
      }
      case OP_SETLIST: {
        int n = GETARG_B(i);
        int c = GETARG_C(i);
        int last;
        Table *h;
        if (n == 0) {
          n = cast_int(L->top - ra) - 1;
          L->top = L->ci->top;
        }
        if (c == 0) c = cast_int(*pc++);
        runtime_check(L, ttistable(ra));
        h = hvalue(ra);
        last = ((c-1)*LFIELDS_PER_FLUSH) + n;
        if (last > h->sizearray)  /* needs more space? */
          luaH_resizearray(L, h, last);  /* pre-alloc it at once */
        for (; n > 0; n--) {
          TValue *val = ra+n;
          setobj2t(L, luaH_setnum(L, h, last--), val);
          luaC_barriert(L, h, val);
        }
        continue;
      }
      case OP_CLOSE: {
        luaF_close(L, ra);
        continue;
      }
      case OP_CLOSURE: {
        Proto *p;
        Closure *ncl;
        int nup, j;
        p = cl->p->p[GETARG_Bx(i)];
        nup = p->nups;
        ncl = luaF_newLclosure(L, nup, cl->env);
        ncl->l.p = p;
        for (j=0; j<nup; j++, pc++) {
          if (GET_OPCODE(*pc) == OP_GETUPVAL)
            ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
          else {
            lua_assert(GET_OPCODE(*pc) == OP_MOVE);
            ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
          }
        }
        setclvalue(L, ra, ncl);
        Protect(luaC_checkGC(L));
        continue;
      }
      case OP_VARARG: {
        int b = GETARG_B(i) - 1;
        int j;
        CallInfo *ci = L->ci;
        int n = cast_int(ci->base - ci->func) - cl->p->numparams - 1;
        if (b == LUA_MULTRET) {
          Protect(luaD_checkstack(L, n));
          ra = RA(i);  /* previous call may change the stack */
          b = n;
          L->top = ra + n;
        }
        for (j = 0; j < b; j++) {
          if (j < n) {
            setobjs2s(L, ra + j, ci->base - n + j);
          }
          else {
            setnilvalue(ra + j);
          }
        }
        continue;
      }
    }
  }
}

References Arith(), arith_op, CallInfo::base, lua_State::base, call_binTM(), cast_int, cast_num, lua_State::ci, clvalue, dojump, equalobj, CallInfo::func, GET_OPCODE, GETARG_A, GETARG_B, GETARG_Bx, GETARG_C, GETARG_sBx, lua_State::hookcount, lua_State::hookmask, hvalue, isLua, Proto::k, KBx, Closure::l, l_isfalse, lessequal(), LFIELDS_PER_FLUSH, lua_assert, LUA_MASKCOUNT, LUA_MASKLINE, LUA_MULTRET, LUA_QL, LUA_TSTRING, LUA_TTABLE, LUA_YIELD, luaC_barrier, luaC_barriert, luaC_checkGC, luaD_call(), luaD_checkstack, luaD_poscall(), luaD_precall(), luaF_close(), luaF_findupval(), luaF_newLclosure(), luaG_checkopenop(), luaG_runerror(), luaG_typeerror(), luaH_getn(), luaH_new(), luaH_resizearray(), luaH_setnum(), luai_numadd, luai_numdiv, luai_numle, luai_numlt, luai_nummod, luai_nummul, luai_numpow, luai_numsub, luai_numunm, luaO_fb2int(), luaO_nilobject, luaV_concat(), luaV_gettable, luaV_lessthan(), luaV_settable, Proto::numparams, Proto::nups, nvalue, OP_ADD, OP_CALL, OP_CLOSE, OP_CLOSURE, OP_CONCAT, OP_DIV, OP_EQ, OP_FORLOOP, OP_FORPREP, OP_GETGLOBAL, OP_GETTABLE, OP_GETUPVAL, OP_JMP, OP_LE, OP_LEN, OP_LOADBOOL, OP_LOADK, OP_LOADNIL, OP_LT, OP_MOD, OP_MOVE, OP_MUL, OP_NEWTABLE, OP_NOT, OP_POW, OP_RETURN, OP_SELF, OP_SETGLOBAL, OP_SETLIST, OP_SETTABLE, OP_SETUPVAL, OP_SUB, OP_TAILCALL, OP_TEST, OP_TESTSET, OP_TFORLOOP, OP_UNM, OP_VARARG, lua_State::openupval, Proto::p, LClosure::p, PCRC, PCRLUA, Protect, RA, RB, RKB, RKC, runtime_check, CallInfo::savedpc, lua_State::savedpc, setbvalue, setclvalue, sethvalue, setnilvalue, setnvalue, setobj, setobj2s, setobj2t, setobjs2s, Table::sizearray, lua_State::stack, lua_State::stacksize, lua_State::status, CallInfo::tailcalls, TM_ADD, TM_DIV, TM_LEN, TM_MOD, TM_MUL, TM_POW, TM_SUB, TM_UNM, tonumber, CallInfo::top, lua_State::top, traceexec(), tsvalue, ttisnil, ttisnumber, ttisstring, ttistable, ttype, LClosure::upvals, and UpVal::v.

Referenced by ccall(), luaD_call(), luaD_call(), resume(), resume(), resume(), resume(), unroll(), unroll(), and unroll().

luaV_gettable()

LUAI_FUNC void luaV_gettable	(	lua_State *	L,
		const TValue *	t,
		TValue *	key,
		StkId	val )

Definition at line 108 of file lua-5.1.5/src/lvm.c.

                                                                           {
  int loop;
  for (loop = 0; loop < MAXTAGLOOP; loop++) {
    const TValue *tm;
    if (ttistable(t)) {  /* `t' is a table? */
      Table *h = hvalue(t);
      const TValue *res = luaH_get(h, key); /* do a primitive get */
      if (!ttisnil(res) ||  /* result is no nil? */
          (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
        setobj2s(L, val, res);
        return;
      }
      /* else will try the tag method */
    }
    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
      luaG_typeerror(L, t, "index");
    if (ttisfunction(tm)) {
      callTMres(L, val, tm, t, key);
      return;
    }
    t = tm;  /* else repeat with `tm' */ 
  }
  luaG_runerror(L, "loop in gettable");
}

luaV_lessthan()

LUAI_FUNC int luaV_lessthan	(	lua_State *	L,
		const TValue *	l,
		const TValue *	r )

Definition at line 225 of file lua-5.1.5/src/lvm.c.

                                                                   {
  int res;
  if (ttype(l) != ttype(r))
    return luaG_ordererror(L, l, r);
  else if (ttisnumber(l))
    return luai_numlt(nvalue(l), nvalue(r));
  else if (ttisstring(l))
    return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
  else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
    return res;
  return luaG_ordererror(L, l, r);
}

luaV_settable()

LUAI_FUNC void luaV_settable	(	lua_State *	L,
		const TValue *	t,
		TValue *	key,
		StkId	val )

Definition at line 134 of file lua-5.1.5/src/lvm.c.

                                                                           {
  int loop;
  TValue temp;
  for (loop = 0; loop < MAXTAGLOOP; loop++) {
    const TValue *tm;
    if (ttistable(t)) {  /* `t' is a table? */
      Table *h = hvalue(t);
      TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
      if (!ttisnil(oldval) ||  /* result is no nil? */
          (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
        setobj2t(L, oldval, val);
        h->flags = 0;
        luaC_barriert(L, h, val);
        return;
      }
      /* else will try the tag method */
    }
    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
      luaG_typeerror(L, t, "index");
    if (ttisfunction(tm)) {
      callTM(L, tm, t, key, val);
      return;
    }
    /* else repeat with `tm' */
    setobj(L, &temp, tm);  /* avoid pointing inside table (may rehash) */
    t = &temp;
  }
  luaG_runerror(L, "loop in settable");
}

luaV_tonumber()

LUAI_FUNC const TValue * luaV_tonumber	(	const TValue *	obj,
		TValue *	n )

Definition at line 35 of file lua-5.1.5/src/lvm.c.

                                                           {
  lua_Number num;
  if (ttisnumber(obj)) return obj;
  if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
    setnvalue(n, num);
    return n;
  }
  else
    return NULL;
}

luaV_tostring()

LUAI_FUNC int luaV_tostring	(	lua_State *	L,
		StkId	obj )

Definition at line 47 of file lua-5.1.5/src/lvm.c.

                                            {
  if (!ttisnumber(obj))
    return 0;
  else {
    char s[LUAI_MAXNUMBER2STR];
    lua_Number n = nvalue(obj);
    lua_number2str(s, n);
    setsvalue2s(L, obj, luaS_new(L, s));
    return 1;
  }
}