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authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>1994-11-07 13:19:51 -0200
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>1994-11-07 13:19:51 -0200
commit62ec3797d518f55513c992fe1819dc5dbb072226 (patch)
tree49e67df51adfdf3887cf0a835b263d2e96a42128 /hash.c
parent0a5dce57044b782a211ce53896967b90fb81ce69 (diff)
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inheritance is not built-in
Diffstat (limited to 'hash.c')
-rw-r--r--hash.c40
1 files changed, 5 insertions, 35 deletions
diff --git a/hash.c b/hash.c
index bed99340..e0df91cc 100644
--- a/hash.c
+++ b/hash.c
@@ -3,7 +3,7 @@
3** hash manager for lua 3** hash manager for lua
4*/ 4*/
5 5
6char *rcs_hash="$Id: hash.c,v 2.11 1994/11/02 20:29:09 roberto Exp roberto $"; 6char *rcs_hash="$Id: hash.c,v 2.12 1994/11/03 22:20:15 roberto Exp $";
7 7
8#include <string.h> 8#include <string.h>
9#include <stdlib.h> 9#include <stdlib.h>
@@ -235,47 +235,17 @@ static void rehash (Hash *t)
235} 235}
236 236
237/* 237/*
238** If the hash node is present, return its pointer, otherwise search 238** If the hash node is present, return its pointer, otherwise return
239** the node at parent table, recursively, if there is parent. 239** null.
240** If no parent and the node is not present, return a static nil object.
241*/ 240*/
242Object *lua_hashget (Hash *t, Object *ref) 241Object *lua_hashget (Hash *t, Object *ref)
243{ 242{
244 static int count = 1000;
245 static Object nil_obj = {LUA_T_NIL, {NULL}};
246 int h = present(t, ref); 243 int h = present(t, ref);
247 if (tag(ref(node(t, h))) != LUA_T_NIL) return val(node(t, h)); 244 if (tag(ref(node(t, h))) != LUA_T_NIL) return val(node(t, h));
248 if (--count == 0) 245 else return NULL;
249 lua_reportbug ("hierarchy too deep (maybe there is an inheritance loop)");
250 { /* check "parent" or "godparent" field */
251 Hash *p;
252 Object parent;
253 Object godparent;
254 tag(&parent) = LUA_T_STRING; svalue(&parent) = "parent";
255 tag(&godparent) = LUA_T_STRING; svalue(&godparent) = "godparent";
256
257 h = present(t, &parent);
258 p = tag(ref(node(t, h))) != LUA_T_NIL && tag(val(node(t, h))) == LUA_T_ARRAY ?
259 avalue(val(node(t, h))) : NULL;
260 if (p != NULL)
261 {
262 Object *r = lua_hashget(p, ref);
263 if (tag(r) != LUA_T_NIL) { count++; return r; }
264 }
265
266 h = present(t, &godparent);
267 p = tag(ref(node(t, h))) != LUA_T_NIL && tag(val(node(t, h))) == LUA_T_ARRAY ?
268 avalue(val(node(t, h))) : NULL;
269 if (p != NULL)
270 {
271 Object *r = lua_hashget(p, ref);
272 if (tag(r) != LUA_T_NIL) { count++; return r; }
273 }
274 }
275 count++;
276 return &nil_obj;
277} 246}
278 247
248
279/* 249/*
280** If the hash node is present, return its pointer, otherwise create a new 250** If the hash node is present, return its pointer, otherwise create a new
281** node for the given reference and also return its pointer. 251** node for the given reference and also return its pointer.