commit fb1cf6ab2d12bd61e3d429830ab20d4ff3c39fd9
parent 19ca2087de4002600b891cf78b3c9b1d939ba2ca
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 8 Feb 1999 15:07:37 -0200
clearer way to set tables.
Diffstat:
5 files changed, 46 insertions(+), 45 deletions(-)
diff --git a/lapi.c b/lapi.c
@@ -1,5 +1,5 @@
/*
-** $Id: lapi.c,v 1.33 1999/02/03 16:42:42 roberto Exp roberto $
+** $Id: lapi.c,v 1.34 1999/02/04 17:47:59 roberto Exp roberto $
** Lua API
** See Copyright Notice in lua.h
*/
@@ -181,7 +181,8 @@ lua_Object lua_rawgettable (void)
void lua_settable (void) {
checkCparams(3);
- luaV_settable(L->stack.top-3, 0);
+ luaV_settable(L->stack.top-3);
+ L->stack.top -= 2; /* pop table and index */
}
diff --git a/lopcodes.h b/lopcodes.h
@@ -1,5 +1,5 @@
/*
-** $Id: lopcodes.h,v 1.20 1999/02/02 19:41:17 roberto Exp roberto $
+** $Id: lopcodes.h,v 1.21 1999/02/04 16:36:16 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -55,8 +55,8 @@ SETGLOBAL,/* b x - VAR[CNST[b]]=x */
SETGLOBALDUPW,/*w x x VAR[CNST[w]]=x */
SETGLOBALDUP,/* b x x VAR[CNST[b]]=x */
-SETTABLE0,/* - v i t - t[i]=v */
-SETTABLEDUP,/* - v i t v t[i]=v */
+SETTABLEPOP,/* - v i t - t[i]=v */
+SETTABPPDUP,/* - v i t v t[i]=v */
SETTABLE,/* b v a_b...a_1 i t a_b...a_1 i t t[i]=v */
diff --git a/lparser.c b/lparser.c
@@ -1,5 +1,5 @@
/*
-** $Id: lparser.c,v 1.15 1999/02/04 16:36:16 roberto Exp roberto $
+** $Id: lparser.c,v 1.16 1999/02/04 17:47:59 roberto Exp roberto $
** LL(1) Parser and code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -490,7 +490,7 @@ static void genstorevar (LexState *ls, vardesc *var, OpCode *codes) {
static void storevar (LexState *ls, vardesc *var) {
- static OpCode codes[] = {SETLOCAL, SETGLOBAL, SETTABLE0};
+ static OpCode codes[] = {SETLOCAL, SETGLOBAL, SETTABLEPOP};
genstorevar(ls, var, codes);
}
@@ -954,7 +954,7 @@ static void exp0 (LexState *ls, vardesc *v) {
static void Gexp (LexState *ls, vardesc *v) {
/* Gexp -> exp0 | var '=' exp1 */
- static OpCode codes[] = {SETLOCALDUP, SETGLOBALDUP, SETTABLEDUP};
+ static OpCode codes[] = {SETLOCALDUP, SETGLOBALDUP, SETTABPPDUP};
exp0(ls, v);
if (v->k != VEXP && optional(ls, '=')) { /* assignment expression? */
unloaddot(ls, v);
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 1.44 1999/02/04 16:36:16 roberto Exp roberto $
+** $Id: lvm.c,v 1.45 1999/02/04 17:47:59 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -110,64 +110,62 @@ void luaV_closure (int nelems) {
** Receives the table at top-2 and the index at top-1.
*/
void luaV_gettable (void) {
- struct Stack *S = &L->stack;
+ TObject *table = L->stack.top-2;
TObject *im;
- if (ttype(S->top-2) != LUA_T_ARRAY) /* not a table, get "gettable" method */
- im = luaT_getimbyObj(S->top-2, IM_GETTABLE);
+ if (ttype(table) != LUA_T_ARRAY) { /* not a table, get gettable method */
+ im = luaT_getimbyObj(table, IM_GETTABLE);
+ if (ttype(im) == LUA_T_NIL)
+ lua_error("indexed expression not a table");
+ }
else { /* object is a table... */
- int tg = (S->top-2)->value.a->htag;
+ int tg = table->value.a->htag;
im = luaT_getim(tg, IM_GETTABLE);
if (ttype(im) == LUA_T_NIL) { /* and does not have a "gettable" method */
- TObject *h = luaH_get(avalue(S->top-2), S->top-1);
- if (ttype(h) != LUA_T_NIL) {
- --S->top;
- *(S->top-1) = *h;
+ TObject *h = luaH_get(avalue(table), table+1);
+ if (ttype(h) == LUA_T_NIL &&
+ (ttype(im=luaT_getim(tg, IM_INDEX)) != LUA_T_NIL)) {
+ /* result is nil and there is an "index" tag method */
+ luaD_callTM(im, 2, 1); /* calls it */
}
- else if (ttype(im=luaT_getim(tg, IM_INDEX)) != LUA_T_NIL)
- luaD_callTM(im, 2, 1);
else {
- --S->top;
- ttype(S->top-1) = LUA_T_NIL;
+ L->stack.top--;
+ *table = *h; /* "push" result into table position */
}
return;
}
/* else it has a "gettable" method, go through to next command */
}
/* object is not a table, or it has a "gettable" method */
- if (ttype(im) == LUA_T_NIL)
- lua_error("indexed expression not a table");
luaD_callTM(im, 2, 1);
}
/*
-** Function to store indexed based on values at the stack.top
-** deep = 1: "deep L->stack.stack" store (with tag methods)
+** Receives table at *t, index at *(t+1) and value at top.
*/
-void luaV_settable (TObject *t, int deep) {
+void luaV_settable (TObject *t) {
struct Stack *S = &L->stack;
TObject *im;
- if (ttype(t) != LUA_T_ARRAY) /* not a table, get "settable" method */
+ if (ttype(t) != LUA_T_ARRAY) { /* not a table, get "settable" method */
im = luaT_getimbyObj(t, IM_SETTABLE);
+ if (ttype(im) == LUA_T_NIL)
+ lua_error("indexed expression not a table");
+ }
else { /* object is a table... */
im = luaT_getim(avalue(t)->htag, IM_SETTABLE);
if (ttype(im) == LUA_T_NIL) { /* and does not have a "settable" method */
luaH_set(avalue(t), t+1, S->top-1);
- /* if deep, pop only value; otherwise, pop table, index and value */
- S->top -= (deep) ? 1 : 3;
+ S->top--; /* pop value */
return;
}
/* else it has a "settable" method, go through to next command */
}
/* object is not a table, or it has a "settable" method */
- if (ttype(im) == LUA_T_NIL)
- lua_error("indexed expression not a table");
- if (deep) { /* table and index were not on top; copy them */
- *(S->top+1) = *(L->stack.top-1);
- *(S->top) = *(t+1);
- *(S->top-1) = *t;
- S->top += 2; /* WARNING: caller must assure stack space */
- }
+ /* prepare arguments and call the tag method */
+ *(S->top+1) = *(L->stack.top-1);
+ *(S->top) = *(t+1);
+ *(S->top-1) = *t;
+ S->top += 2; /* WARNING: caller must assure stack space */
luaD_callTM(im, 3, 0);
}
@@ -421,19 +419,21 @@ StkId luaV_execute (Closure *cl, TProtoFunc *tf, StkId base) {
luaV_setglobal(tsvalue(&consts[aux]));
break;
- case SETTABLE0:
- luaV_settable(S->top-3, 0);
+ case SETTABLEPOP:
+ luaV_settable(S->top-3);
+ S->top -= 2; /* pop table and index */
break;
- case SETTABLEDUP: {
+ case SETTABPPDUP: {
TObject temp = *(S->top-1);
- luaV_settable(S->top-3, 0);
- *(S->top++) = temp;
+ luaV_settable(S->top-3);
+ S->top--; /* pop index (temp goes into "table" position) */
+ *(S->top-1) = temp;
break;
}
case SETTABLE:
- luaV_settable(S->top-3-(*pc++), 1);
+ luaV_settable(S->top-3-(*pc++));
break;
case SETLISTW: aux += highbyte(*pc++);
diff --git a/lvm.h b/lvm.h
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.h,v 1.6 1998/12/30 13:16:50 roberto Exp roberto $
+** $Id: lvm.h,v 1.7 1998/12/30 17:26:49 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -22,7 +22,7 @@ int luaV_tonumber (TObject *obj);
int luaV_tostring (TObject *obj);
void luaV_setn (Hash *t, int val);
void luaV_gettable (void);
-void luaV_settable (TObject *t, int deep);
+void luaV_settable (TObject *t);
void luaV_rawsettable (TObject *t);
void luaV_getglobal (TaggedString *ts);
void luaV_setglobal (TaggedString *ts);
