From 69e0240978fe86d032167711a9b6c7058db0c897 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 10 Sep 2007 14:59:32 -0300
Subject: [PATCH] tables and strings respect __len metamethod
---
src/blua/ltm.c | 4 ++--
src/blua/ltm.h | 2 +-
src/blua/lvm.c | 45 ++++++++++++++++++++++++++++-----------------
3 files changed, 31 insertions(+), 20 deletions(-)
diff --git a/src/blua/ltm.c b/src/blua/ltm.c
index 031a2811e9..570bded697 100644
--- a/src/blua/ltm.c
+++ b/src/blua/ltm.c
@@ -31,9 +31,9 @@ void luaT_init (lua_State *L) {
static const char *const luaT_eventname[] = { /* ORDER TM */
"__index", "__newindex",
"__usedindex",
- "__gc", "__mode", "__eq",
+ "__gc", "__mode", "__len", "__eq",
"__add", "__sub", "__mul", "__div", "__mod",
- "__pow", "__unm", "__len", "__lt", "__le",
+ "__pow", "__unm", "__lt", "__le",
"__concat", "__call"
,"__strhook"
,"__and", "__or", "__xor", "__shl", "__shr", "__not"
diff --git a/src/blua/ltm.h b/src/blua/ltm.h
index 3d4ac8c0ec..3f2aa4a45a 100644
--- a/src/blua/ltm.h
+++ b/src/blua/ltm.h
@@ -21,6 +21,7 @@ typedef enum {
TM_USEDINDEX,
TM_GC,
TM_MODE,
+ TM_LEN,
TM_EQ, /* last tag method with `fast' access */
TM_ADD,
TM_SUB,
@@ -29,7 +30,6 @@ typedef enum {
TM_MOD,
TM_POW,
TM_UNM,
- TM_LEN,
TM_LT,
TM_LE,
TM_CONCAT,
diff --git a/src/blua/lvm.c b/src/blua/lvm.c
index 46a015c1eb..b74fef4ee3 100644
--- a/src/blua/lvm.c
+++ b/src/blua/lvm.c
@@ -311,6 +311,33 @@ void luaV_concat (lua_State *L, int total, int last) {
}
+static void objlen (lua_State *L, StkId ra, TValue *rb) {
+ const TValue *tm;
+ switch (ttype(rb)) {
+ case LUA_TTABLE: {
+ Table *h = hvalue(rb);
+ tm = fasttm(L, h->metatable, TM_LEN);
+ if (tm) break; /* metamethod? break switch to call it */
+ setnvalue(ra, cast_num(luaH_getn(h))); /* else primitive len */
+ return;
+ }
+ case LUA_TSTRING: {
+ tm = fasttm(L, G(L)->mt[LUA_TSTRING], TM_LEN);
+ if (tm) break; /* metamethod? break switch to call it */
+ setnvalue(ra, cast_num(tsvalue(rb)->len));
+ return;
+ }
+ default: { /* try metamethod */
+ tm = luaT_gettmbyobj(L, rb, TM_LEN);
+ if (ttisnil(tm)) /* no metamethod? */
+ luaG_typeerror(L, rb, "get length of");
+ break;
+ }
+ }
+ callTMres(L, ra, tm, rb, luaO_nilobject);
+}
+
+
static void Arith (lua_State *L, StkId ra, TValue *rb,
TValue *rc, TMS op) {
TValue tempb, tempc;
@@ -568,23 +595,7 @@ void luaV_execute (lua_State *L, int nexeccalls) {
continue;
}
case OP_LEN: {
- TValue *rb = RB(i);
- switch (ttype(rb)) {
- case LUA_TTABLE: {
- setnvalue(ra, cast_num(luaH_getn(hvalue(rb))));
- break;
- }
- case LUA_TSTRING: {
- setnvalue(ra, cast_num(tsvalue(rb)->len));
- break;
- }
- default: { /* try metamethod */
- Protect(
- if (!call_binTM(L, rb, luaO_nilobject, ra, TM_LEN))
- luaG_typeerror(L, rb, "get length of");
- )
- }
- }
+ Protect(objlen(L, ra, RB(i)));
continue;
}
case OP_CONCAT: {
--
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