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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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63
ltm.c
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@@ -1,5 +1,5 @@
/*
** $Id: ltm.c,v 1.52 2000/10/03 14:27:44 roberto Exp roberto $
** $Id: ltm.c,v 1.53 2000/10/05 12:14:08 roberto Exp roberto $
** Tag methods
** See Copyright Notice in lua.h
*/
@@ -17,7 +17,7 @@
#include "ltm.h"
const char *const luaT_eventname[] = { /* ORDER IM */
const char *const luaT_eventname[] = { /* ORDER TM */
"gettable", "settable", "index", "getglobal", "setglobal", "add", "sub",
"mul", "div", "pow", "unm", "lt", "concat", "gc", "function",
"le", "gt", "ge", /* deprecated options!! */
@@ -36,9 +36,9 @@ static int findevent (const char *name) {
static int luaI_checkevent (lua_State *L, const char *name, int t) {
int e = findevent(name);
if (e >= IM_N)
if (e >= TM_N)
luaO_verror(L, "event `%.50s' is deprecated", name);
if (e == IM_GC && t == LUA_TTABLE)
if (e == TM_GC && t == LUA_TTABLE)
luaO_verror(L, "event `gc' for tables is deprecated");
if (e < 0)
luaO_verror(L, "`%.50s' is not a valid event name", name);
@@ -50,8 +50,8 @@ static int luaI_checkevent (lua_State *L, const char *name, int t) {
/* events in LUA_TNIL are all allowed, since this is used as a
* 'placeholder' for "default" fallbacks
*/
/* ORDER LUA_T, ORDER IM */
static const char luaT_validevents[NUM_TAGS][IM_N] = {
/* ORDER LUA_T, ORDER TM */
static const char luaT_validevents[NUM_TAGS][TM_N] = {
{1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1}, /* LUA_TUSERDATA */
{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, /* LUA_TNIL */
{1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1}, /* LUA_TNUMBER */
@@ -67,16 +67,16 @@ int luaT_validevent (int t, int e) { /* ORDER LUA_T */
static void init_entry (lua_State *L, int tag) {
int i;
for (i=0; i<IM_N; i++)
ttype(luaT_getim(L, tag, i)) = LUA_TNIL;
L->IMtable[tag].collected = NULL;
for (i=0; i<TM_N; i++)
luaT_gettm(L, tag, i) = NULL;
L->TMtable[tag].collected = NULL;
}
void luaT_init (lua_State *L) {
int t;
luaM_growvector(L, L->IMtable, 0, NUM_TAGS, struct IM, "", MAX_INT);
L->nblocks += NUM_TAGS*sizeof(struct IM);
luaM_growvector(L, L->TMtable, 0, NUM_TAGS, struct TM, "", MAX_INT);
L->nblocks += NUM_TAGS*sizeof(struct TM);
L->last_tag = NUM_TAGS-1;
for (t=0; t<=L->last_tag; t++)
init_entry(L, t);
@@ -84,9 +84,9 @@ void luaT_init (lua_State *L) {
int lua_newtag (lua_State *L) {
luaM_growvector(L, L->IMtable, L->last_tag, 1, struct IM,
luaM_growvector(L, L->TMtable, L->last_tag, 1, struct TM,
"tag table overflow", MAX_INT);
L->nblocks += sizeof(struct IM);
L->nblocks += sizeof(struct TM);
L->last_tag++;
init_entry(L, L->last_tag);
return L->last_tag;
@@ -108,9 +108,9 @@ int lua_copytagmethods (lua_State *L, int tagto, int tagfrom) {
int e;
checktag(L, tagto);
checktag(L, tagfrom);
for (e=0; e<IM_N; e++) {
for (e=0; e<TM_N; e++) {
if (luaT_validevent(tagto, e))
*luaT_getim(L, tagto, e) = *luaT_getim(L, tagfrom, e);
luaT_gettm(L, tagto, e) = luaT_gettm(L, tagfrom, e);
}
return tagto;
}
@@ -130,8 +130,10 @@ void lua_gettagmethod (lua_State *L, int t, const char *event) {
int e;
e = luaI_checkevent(L, event, t);
checktag(L, t);
if (luaT_validevent(t, e))
*L->top = *luaT_getim(L, t,e);
if (luaT_validevent(t, e) && luaT_gettm(L, t, e)) {
clvalue(L->top) = luaT_gettm(L, t, e);
ttype(L->top) = LUA_TFUNCTION;
}
else
ttype(L->top) = LUA_TNIL;
incr_top;
@@ -139,19 +141,26 @@ void lua_gettagmethod (lua_State *L, int t, const char *event) {
void lua_settagmethod (lua_State *L, int t, const char *event) {
TObject temp;
int e;
LUA_ASSERT(lua_isnil(L, -1) || lua_isfunction(L, -1),
"function or nil expected");
e = luaI_checkevent(L, event, t);
Closure *oldtm;
int e = luaI_checkevent(L, event, t);
checktag(L, t);
if (!luaT_validevent(t, e))
luaO_verror(L, "cannot change `%.20s' tag method for type `%.20s'%.20s",
luaT_eventname[e], luaO_typenames[t],
(t == LUA_TTABLE || t == LUA_TUSERDATA) ? " with default tag"
: "");
temp = *(L->top - 1);
*(L->top - 1) = *luaT_getim(L, t,e);
*luaT_getim(L, t, e) = temp;
(t == LUA_TTABLE || t == LUA_TUSERDATA) ?
" with default tag" : "");
oldtm = luaT_gettm(L, t, e);
switch (ttype(L->top - 1)) {
case LUA_TNIL:
luaT_gettm(L, t, e) = NULL;
break;
case LUA_TFUNCTION:
luaT_gettm(L, t, e) = clvalue(L->top - 1);
break;
default:
lua_error(L, "tag method must be a function (or nil)");
}
clvalue(L->top - 1) = oldtm;
ttype(L->top - 1) = (oldtm ? LUA_TFUNCTION : LUA_TNIL);
}