From 6980cb1aa7bb0238b9cb916320b0c6365bfbb10e Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 17 Jun 2009 14:53:14 -0300
Subject: [PATCH] new functions 'lua_arith' and 'lua_compare'

---
 lapi.c   | 36 +++++++++++++++++++-----------------
 ltests.c | 16 ++++++++++------
 lua.h    | 31 ++++++++++++++++++++++++++-----
 3 files changed, 55 insertions(+), 28 deletions(-)

diff --git a/lapi.c b/lapi.c
index 8f07a35b..d2a2f705 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.78 2009/06/01 19:09:26 roberto Exp roberto $
+** $Id: lapi.c,v 2.79 2009/06/15 19:51:31 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -275,32 +275,34 @@ LUA_API int lua_rawequal (lua_State *L, int index1, int index2) {
 }
 
 
-LUA_API int lua_equal (lua_State *L, int index1, int index2) {
+LUA_API void  lua_arith (lua_State *L, int op) {
+  lua_lock(L);
+  api_checknelems(L, 2);
+  luaV_arith(L, L->top - 2, L->top - 2, L->top - 1, op - LUA_OPADD + TM_ADD);
+  L->top--;
+  lua_unlock(L);
+}
+
+
+LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) {
   StkId o1, o2;
   int i;
   lua_lock(L);  /* may call tag method */
   o1 = index2adr(L, index1);
   o2 = index2adr(L, index2);
-  i = (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0 : equalobj(L, o1, o2);
+  if (o1 == luaO_nilobject || o2 == luaO_nilobject)
+    i = 0;
+  else switch (op) {
+    case LUA_OPEQ: i = equalobj(L, o1, o2); break;
+    case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break;
+    case LUA_OPLE: i = luaV_lessequal(L, o1, o2); break;
+    default: api_check(L, 0); i = 0;
+  }
   lua_unlock(L);
   return i;
 }
 
 
-LUA_API int lua_lessthan (lua_State *L, int index1, int index2) {
-  StkId o1, o2;
-  int i;
-  lua_lock(L);  /* may call tag method */
-  o1 = index2adr(L, index1);
-  o2 = index2adr(L, index2);
-  i = (o1 == luaO_nilobject || o2 == luaO_nilobject) ? 0
-       : luaV_lessthan(L, o1, o2);
-  lua_unlock(L);
-  return i;
-}
-
-
-
 LUA_API lua_Number lua_tonumber (lua_State *L, int idx) {
   TValue n;
   const TValue *o = index2adr(L, idx);
diff --git a/ltests.c b/ltests.c
index cb451f98..bc5a21e0 100644
--- a/ltests.c
+++ b/ltests.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltests.c,v 2.64 2009/06/10 16:57:53 roberto Exp roberto $
+** $Id: ltests.c,v 2.65 2009/06/15 19:51:31 roberto Exp roberto $
 ** Internal Module for Debugging of the Lua Implementation
 ** See Copyright Notice in lua.h
 */
@@ -971,13 +971,17 @@ static int runC (lua_State *L, lua_State *L1, const char *pc) {
     else if EQ("concat") {
       lua_concat(L1, getnum);
     }
-    else if EQ("lessthan") {
-      int a = getindex;
-      lua_pushboolean(L1, lua_lessthan(L1, a, getindex));
+    else if EQ("arith") {
+      static char ops[] = "+-*/%^_";
+      int op;
+      skip(&pc);
+      op = strchr(ops, *pc++) - ops;
+      lua_arith(L, op);
     }
-    else if EQ("equal") {
+    else if EQ("compare") {
       int a = getindex;
-      lua_pushboolean(L1, lua_equal(L1, a, getindex));
+      int b = getindex;
+      lua_pushboolean(L1, lua_compare(L1, a, b, getnum));
     }
     else if EQ("call") {
       int narg = getnum;
diff --git a/lua.h b/lua.h
index 62205158..aa242e8e 100644
--- a/lua.h
+++ b/lua.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lua.h,v 1.237 2009/05/21 20:06:11 roberto Exp roberto $
+** $Id: lua.h,v 1.238 2009/06/15 19:51:31 roberto Exp roberto $
 ** Lua - An Extensible Extension Language
 ** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
 ** See Copyright Notice at the end of this file
@@ -147,10 +147,6 @@ LUA_API int             (lua_isuserdata) (lua_State *L, int idx);
 LUA_API int             (lua_type) (lua_State *L, int idx);
 LUA_API const char     *(lua_typename) (lua_State *L, int tp);
 
-LUA_API int            (lua_equal) (lua_State *L, int idx1, int idx2);
-LUA_API int            (lua_rawequal) (lua_State *L, int idx1, int idx2);
-LUA_API int            (lua_lessthan) (lua_State *L, int idx1, int idx2);
-
 LUA_API lua_Number      (lua_tonumber) (lua_State *L, int idx);
 LUA_API lua_Integer     (lua_tointeger) (lua_State *L, int idx);
 LUA_API int             (lua_toboolean) (lua_State *L, int idx);
@@ -162,6 +158,28 @@ LUA_API lua_State      *(lua_tothread) (lua_State *L, int idx);
 LUA_API const void     *(lua_topointer) (lua_State *L, int idx);
 
 
+/*
+** Comparison and arithmetic functions
+*/
+
+#define LUA_OPADD	0	/* ORDER TM */
+#define LUA_OPSUB	1
+#define LUA_OPMUL	2
+#define LUA_OPDIV	3
+#define LUA_OPMOD	4
+#define LUA_OPPOW	5
+#define LUA_OPUNM	6
+
+LUA_API void  (lua_arith) (lua_State *L, int op);
+
+#define LUA_OPEQ	0
+#define LUA_OPLT	1
+#define LUA_OPLE	2
+
+LUA_API int   (lua_rawequal) (lua_State *L, int idx1, int idx2);
+LUA_API int   (lua_compare) (lua_State *L, int idx1, int idx2, int op);
+
+
 /*
 ** push functions (C -> stack)
 */
@@ -310,6 +328,9 @@ LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 #define lua_Chunkreader		lua_Reader
 #define lua_Chunkwriter		lua_Writer
 
+#define lua_equal(L,idx1,idx2)		lua_compare(L,(idx1),(idx2),LUA_OPEQ)
+#define lua_lessthan(L,idx1,idx2)	lua_compare(L,(idx1),(idx2),LUA_OPLT)
+
 #endif