commit b7edf5d2d89ed2ce1e9087de496bcb451e39d131
parent ef8263f81fdde2310ebb15c9a3fe5e954d57cab5
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 27 Feb 2018 14:48:01 -0300
metamethods for 'removekey'/'keyin'
Diffstat:
4 files changed, 46 insertions(+), 18 deletions(-)
diff --git a/lapi.c b/lapi.c
@@ -1,5 +1,5 @@
/*
-** $Id: lapi.c,v 2.287 2018/02/25 12:48:16 roberto Exp roberto $
+** $Id: lapi.c,v 2.288 2018/02/26 14:16:05 roberto Exp roberto $
** Lua API
** See Copyright Notice in lua.h
*/
@@ -679,6 +679,7 @@ LUA_API int lua_rawget (lua_State *L, int idx) {
Table *t;
const TValue *val;
lua_lock(L);
+ api_checknelems(L, 1);
t = gettable(L, idx);
val = luaH_get(t, s2v(L->top - 1));
L->top--; /* remove key */
@@ -704,29 +705,24 @@ LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) {
}
-static int auxkeyman (lua_State *L, int idx, int remove) {
- Table *t;
- const TValue *val;
+static int auxkeydef (lua_State *L, int idx, int remove) {
int res;
lua_lock(L);
- t = gettable(L, idx);
- val = luaH_get(t, s2v(L->top - 1));
+ api_checknelems(L, 1);
+ res = luaT_keydef(L, index2value(L, idx), s2v(L->top - 1), remove);
L->top--; /* remove key */
- res = !isempty(val);
- if (remove && res) /* key is present and should be removed? */
- setempty(cast(TValue*, val));
lua_unlock(L);
return res;
}
LUA_API void lua_removekey (lua_State *L, int idx) {
- auxkeyman(L, idx, 1);
+ auxkeydef(L, idx, 1);
}
LUA_API int lua_keyin (lua_State *L, int idx) {
- return auxkeyman(L, idx, 0);
+ return auxkeydef(L, idx, 0);
}
@@ -1223,6 +1219,7 @@ LUA_API int lua_next (lua_State *L, int idx) {
Table *t;
int more;
lua_lock(L);
+ api_checknelems(L, 1);
t = gettable(L, idx);
more = luaH_next(L, t, L->top - 1);
if (more) {
diff --git a/lbaselib.c b/lbaselib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lbaselib.c,v 1.319 2018/02/05 17:10:52 roberto Exp roberto $
+** $Id: lbaselib.c,v 1.320 2018/02/25 12:48:16 roberto Exp roberto $
** Basic library
** See Copyright Notice in lua.h
*/
@@ -171,8 +171,7 @@ static int luaB_rawset (lua_State *L) {
static int luaB_keyin (lua_State *L) {
- luaL_checktype(L, 1, LUA_TTABLE);
- luaL_checkany(L, 2);
+ luaL_checkany(L, 2); /* ensures a first argument too */
lua_settop(L, 2);
lua_pushboolean(L, lua_keyin(L, 1));
return 1;
@@ -180,8 +179,7 @@ static int luaB_keyin (lua_State *L) {
static int luaB_removekey (lua_State *L) {
- luaL_checktype(L, 1, LUA_TTABLE);
- luaL_checkany(L, 2);
+ luaL_checkany(L, 2); /* ensures a first argument too */
lua_settop(L, 2);
lua_removekey(L, 1);
return 0;
diff --git a/ltm.c b/ltm.c
@@ -1,5 +1,5 @@
/*
-** $Id: ltm.c,v 2.64 2018/02/23 13:13:31 roberto Exp roberto $
+** $Id: ltm.c,v 2.65 2018/02/26 14:16:05 roberto Exp roberto $
** Tag methods
** See Copyright Notice in lua.h
*/
@@ -38,6 +38,7 @@ 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",
@@ -248,3 +249,31 @@ void luaT_getvarargs (lua_State *L, CallInfo *ci, StkId where, int wanted) {
for (; i < wanted; i++) /* complete required results with nil */
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
@@ -1,5 +1,5 @@
/*
-** $Id: ltm.h,v 2.32 2018/02/17 19:20:00 roberto Exp roberto $
+** $Id: ltm.h,v 2.33 2018/02/23 13:13:31 roberto Exp roberto $
** Tag methods
** See Copyright Notice in lua.h
*/
@@ -19,6 +19,8 @@
typedef enum {
TM_INDEX,
TM_NEWINDEX,
+ TM_UNDEF,
+ TM_ISDEF,
TM_GC,
TM_MODE,
TM_LEN,
@@ -89,5 +91,7 @@ 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
