new function lua_copy

1 files changed, 29 insertions, 15 deletions

diff --git a/lapi.c b/lapi.c
index 08a42516..8426dea0 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.91 2009/09/21 12:09:52 roberto Exp roberto $
+** $Id: lapi.c,v 2.92 2009/09/28 16:32:50 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -185,32 +185,46 @@ LUA_API void lua_insert (lua_State *L, int idx) {
 }
 
 
-LUA_API void lua_replace (lua_State *L, int idx) {
-  StkId o;
-  lua_lock(L);
-  /* explicit test for incompatible code */
-  if (idx == LUA_ENVIRONINDEX && L->ci->previous == NULL)
-    luaG_runerror(L, "no calling environment");
-  api_checknelems(L, 1);
-  o = index2addr(L, idx);
-  api_checkvalidindex(L, o);
+static void moveto (lua_State *L, TValue *fr, int idx) {
+  TValue *to = index2addr(L, idx);
+  api_checkvalidindex(L, to);
   if (idx == LUA_ENVIRONINDEX) {
     Closure *func = curr_func(L);
-    api_check(L, ttistable(L->top - 1), "table expected");
-    func->c.env = hvalue(L->top - 1);
-    luaC_barrier(L, func, L->top - 1);
+    api_check(L, ttistable(fr), "table expected");
+    func->c.env = hvalue(fr);
+    luaC_barrier(L, func, fr);
   }
   else {
-    setobj(L, o, L->top - 1);
+    setobj(L, to, fr);
     if (idx < LUA_GLOBALSINDEX)  /* function upvalue? */
-      luaC_barrier(L, curr_func(L), L->top - 1);
+      luaC_barrier(L, curr_func(L), fr);
   }
   /* LUA_GLOBALSINDEX does not need gc barrier (threads are never black) */
+}
+
+
+LUA_API void lua_replace (lua_State *L, int idx) {
+  lua_lock(L);
+  /* explicit test for incompatible code */
+  if (idx == LUA_ENVIRONINDEX && L->ci->previous == NULL)
+    luaG_runerror(L, "no calling environment");
+  api_checknelems(L, 1);
+  moveto(L, L->top - 1, idx);
   L->top--;
   lua_unlock(L);
 }
 
 
+LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) {
+  TValue *fr;
+  lua_lock(L);
+  fr = index2addr(L, fromidx);
+  api_checkvalidindex(L, fr);
+  moveto(L, fr, toidx);
+  lua_unlock(L);
+}
+
+
 LUA_API void lua_pushvalue (lua_State *L, int idx) {
   lua_lock(L);
   setobj2s(L, L->top, index2addr(L, idx));