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tag methods are always functions, so don't need to store a whole object

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This commit is contained in:
Roberto Ierusalimschy
2000-10-05 10:00:17 -03:00
parent 001f2bdd0e
commit 046a3d6173
10 changed files with 159 additions and 130 deletions
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77
lvm.c
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@@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 1.142 2000/10/04 12:16:08 roberto Exp roberto $
** $Id: lvm.c,v 1.143 2000/10/05 12:14:08 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -116,27 +116,27 @@ void luaV_Lclosure (lua_State *L, Proto *l, int nelems) {
** Receives the table at `t' and the key at top.
*/
const TObject *luaV_gettable (lua_State *L, StkId t) {
const TObject *im;
Closure *tm;
int tg;
if (ttype(t) == LUA_TTABLE && /* `t' is a table? */
((tg = hvalue(t)->htag) == LUA_TTABLE || /* with default tag? */
ttype(luaT_getim(L, tg, IM_GETTABLE)) == LUA_TNIL)) { /* or no TM? */
luaT_gettm(L, tg, TM_GETTABLE) == NULL)) { /* or no TM? */
/* do a primitive get */
const TObject *h = luaH_get(L, hvalue(t), L->top-1);
/* result is no nil or there is no `index' tag method? */
if (ttype(h) != LUA_TNIL ||
(ttype(im=luaT_getim(L, tg, IM_INDEX)) == LUA_TNIL))
if (ttype(h) != LUA_TNIL || ((tm=luaT_gettm(L, tg, TM_INDEX)) == NULL))
return h; /* return result */
/* else call `index' tag method */
}
else { /* try a `gettable' tag method */
im = luaT_getimbyObj(L, t, IM_GETTABLE);
tm = luaT_gettmbyObj(L, t, TM_GETTABLE);
}
if (ttype(im) != LUA_TNIL) { /* is there a tag method? */
if (tm != NULL) { /* is there a tag method? */
luaD_checkstack(L, 2);
*(L->top+1) = *(L->top-1); /* key */
*L->top = *t; /* table */
*(L->top-1) = *im; /* tag method */
clvalue(L->top-1) = tm; /* tag method */
ttype(L->top-1) = LUA_TFUNCTION;
L->top += 2;
luaD_call(L, L->top - 3, 1);
return L->top - 1; /* call result */
@@ -155,16 +155,17 @@ void luaV_settable (lua_State *L, StkId t, StkId key) {
int tg;
if (ttype(t) == LUA_TTABLE && /* `t' is a table? */
((tg = hvalue(t)->htag) == LUA_TTABLE || /* with default tag? */
ttype(luaT_getim(L, tg, IM_SETTABLE)) == LUA_TNIL)) /* or no TM? */
luaT_gettm(L, tg, TM_SETTABLE) == NULL)) /* or no TM? */
*luaH_set(L, hvalue(t), key) = *(L->top-1); /* do a primitive set */
else { /* try a `settable' tag method */
const TObject *im = luaT_getimbyObj(L, t, IM_SETTABLE);
if (ttype(im) != LUA_TNIL) {
Closure *tm = luaT_gettmbyObj(L, t, TM_SETTABLE);
if (tm != NULL) {
luaD_checkstack(L, 3);
*(L->top+2) = *(L->top-1);
*(L->top+1) = *key;
*(L->top) = *t;
*(L->top-1) = *im;
clvalue(L->top-1) = tm;
ttype(L->top-1) = LUA_TFUNCTION;
L->top += 3;
luaD_call(L, L->top - 4, 0); /* call `settable' tag method */
}
@@ -176,14 +177,15 @@ void luaV_settable (lua_State *L, StkId t, StkId key) {
const TObject *luaV_getglobal (lua_State *L, TString *s) {
const TObject *value = luaH_getstr(L->gt, s);
const TObject *im = luaT_getimbyObj(L, value, IM_GETGLOBAL);
if (ttype(im) == LUA_TNIL) /* is there a tag method? */
Closure *tm = luaT_gettmbyObj(L, value, TM_GETGLOBAL);
if (tm == NULL) /* is there a tag method? */
return value; /* default behavior */
else { /* tag method */
luaD_checkstack(L, 3);
*L->top = *im;
ttype(L->top+1) = LUA_TSTRING;
clvalue(L->top) = tm;
ttype(L->top) = LUA_TFUNCTION;
tsvalue(L->top+1) = s; /* global name */
ttype(L->top+1) = LUA_TSTRING;
*(L->top+2) = *value;
L->top += 3;
luaD_call(L, L->top - 3, 1);
@@ -194,8 +196,8 @@ const TObject *luaV_getglobal (lua_State *L, TString *s) {
void luaV_setglobal (lua_State *L, TString *s) {
const TObject *oldvalue = luaH_getstr(L->gt, s);
const TObject *im = luaT_getimbyObj(L, oldvalue, IM_SETGLOBAL);
if (ttype(im) == LUA_TNIL) { /* is there a tag method? */
Closure *tm = luaT_gettmbyObj(L, oldvalue, TM_SETGLOBAL);
if (tm == NULL) { /* is there a tag method? */
if (oldvalue != &luaO_nilobject) {
/* cast to remove `const' is OK, because `oldvalue' != luaO_nilobject */
*(TObject *)oldvalue = *(L->top - 1);
@@ -213,32 +215,33 @@ void luaV_setglobal (lua_State *L, TString *s) {
*(L->top+1) = *oldvalue;
ttype(L->top) = LUA_TSTRING;
tsvalue(L->top) = s;
*(L->top-1) = *im;
clvalue(L->top-1) = tm;
ttype(L->top-1) = LUA_TFUNCTION;
L->top += 3;
luaD_call(L, L->top - 4, 0);
}
}
static int call_binTM (lua_State *L, StkId top, IMS event) {
static int call_binTM (lua_State *L, StkId top, TMS event) {
/* try first operand */
const TObject *im = luaT_getimbyObj(L, top-2, event);
Closure *tm = luaT_gettmbyObj(L, top-2, event);
L->top = top;
if (ttype(im) == LUA_TNIL) {
im = luaT_getimbyObj(L, top-1, event); /* try second operand */
if (ttype(im) == LUA_TNIL) {
im = luaT_getim(L, 0, event); /* try a `global' method */
if (ttype(im) == LUA_TNIL)
if (tm == NULL) {
tm = luaT_gettmbyObj(L, top-1, event); /* try second operand */
if (tm == NULL) {
tm = luaT_gettm(L, 0, event); /* try a `global' method */
if (tm == NULL)
return 0; /* error */
}
}
lua_pushstring(L, luaT_eventname[event]);
luaD_callTM(L, im, 3, 1);
luaD_callTM(L, tm, 3, 1);
return 1;
}
static void call_arith (lua_State *L, StkId top, IMS event) {
static void call_arith (lua_State *L, StkId top, TMS event) {
if (!call_binTM(L, top, event))
luaG_binerror(L, top-2, LUA_TNUMBER, "perform arithmetic on");
}
@@ -275,7 +278,7 @@ int luaV_lessthan (lua_State *L, const TObject *l, const TObject *r, StkId top)
luaD_checkstack(L, 2);
*top++ = *l;
*top++ = *r;
if (!call_binTM(L, top, IM_LT))
if (!call_binTM(L, top, TM_LT))
luaG_ordererror(L, top-2);
L->top--;
return (ttype(L->top) != LUA_TNIL);
@@ -287,7 +290,7 @@ void luaV_strconc (lua_State *L, int total, StkId top) {
do {
int n = 2; /* number of elements handled in this pass (at least 2) */
if (tostring(L, top-2) || tostring(L, top-1)) {
if (!call_binTM(L, top, IM_CONCAT))
if (!call_binTM(L, top, TM_CONCAT))
luaG_binerror(L, top-2, LUA_TSTRING, "concat");
}
else if (tsvalue(top-1)->u.s.len > 0) { /* if len=0, do nothing */
@@ -517,7 +520,7 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
}
case OP_ADD: {
if (tonumber(top-2) || tonumber(top-1))
call_arith(L, top, IM_ADD);
call_arith(L, top, TM_ADD);
else
nvalue(top-2) += nvalue(top-1);
top--;
@@ -527,7 +530,7 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
if (tonumber(top-1)) {
ttype(top) = LUA_TNUMBER;
nvalue(top) = (Number)GETARG_S(i);
call_arith(L, top+1, IM_ADD);
call_arith(L, top+1, TM_ADD);
}
else
nvalue(top-1) += (Number)GETARG_S(i);
@@ -535,7 +538,7 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
}
case OP_SUB: {
if (tonumber(top-2) || tonumber(top-1))
call_arith(L, top, IM_SUB);
call_arith(L, top, TM_SUB);
else
nvalue(top-2) -= nvalue(top-1);
top--;
@@ -543,7 +546,7 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
}
case OP_MULT: {
if (tonumber(top-2) || tonumber(top-1))
call_arith(L, top, IM_MUL);
call_arith(L, top, TM_MUL);
else
nvalue(top-2) *= nvalue(top-1);
top--;
@@ -551,14 +554,14 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
}
case OP_DIV: {
if (tonumber(top-2) || tonumber(top-1))
call_arith(L, top, IM_DIV);
call_arith(L, top, TM_DIV);
else
nvalue(top-2) /= nvalue(top-1);
top--;
break;
}
case OP_POW: {
if (!call_binTM(L, top, IM_POW))
if (!call_binTM(L, top, TM_POW))
lua_error(L, "undefined operation");
top--;
break;
@@ -574,7 +577,7 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
case OP_MINUS: {
if (tonumber(top-1)) {
ttype(top) = LUA_TNIL;
call_arith(L, top+1, IM_UNM);
call_arith(L, top+1, TM_UNM);
}
else
nvalue(top-1) = -nvalue(top-1);