add lua_arith and lua_compare for Lua 5.1

4 files changed, 152 insertions, 2 deletions

diff --git a/c-api/compat-5.3.c b/c-api/compat-5.3.c
index e45c728..a539aed 100644
--- a/c-api/compat-5.3.c
+++ b/c-api/compat-5.3.c
@@ -24,6 +24,96 @@ COMPAT53_API int lua_absindex (lua_State *L, int i) {
 }
 
 
+static const char compat53_arith_code[] = {
+  'l', 'o', 'c', 'a', 'l', ' ', 'o', 'p', ',', 'a', ',', 'b',
+  '=', '.', '.', '.', '\n',
+  'i', 'f', ' ', 'o', 'p', '=', '=', '0', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '+', 'b', '\n',
+  'e', 'l', 's', 'e', 'i', 'f', ' ', 'o', 'p', '=', '=', '1', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '-', 'b', '\n',
+  'e', 'l', 's', 'e', 'i', 'f', ' ', 'o', 'p', '=', '=', '2', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '*', 'b', '\n',
+  'e', 'l', 's', 'e', 'i', 'f', ' ', 'o', 'p', '=', '=', '3', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '/', 'b', '\n',
+  'e', 'l', 's', 'e', 'i', 'f', ' ', 'o', 'p', '=', '=', '4', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '%', 'b', '\n',
+  'e', 'l', 's', 'e', 'i', 'f', ' ', 'o', 'p', '=', '=', '5', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '^', 'b', '\n',
+  'e', 'l', 's', 'e', 'i', 'f', ' ', 'o', 'p', '=', '=', '6', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', '-', 'a', '\n',
+  'e', 'n', 'd', '\n', '\0'
+};
+
+COMPAT53_API void lua_arith (lua_State *L, int op) {
+  luaL_checkstack(L, 5, "not enough stack slots");
+  if (op == LUA_OPUNM)
+    lua_pushvalue(L, -1);
+  lua_rawgetp(L, LUA_REGISTRYINDEX, (void*)compat53_arith_code);
+  if (lua_type(L, -1) != LUA_TFUNCTION) {
+    lua_pop(L, 1);
+    if (luaL_loadbuffer(L, compat53_arith_code,
+                        sizeof(compat53_arith_code)-1, "=none"))
+      lua_error(L);
+    lua_pushvalue(L, -1);
+    lua_rawsetp(L, LUA_REGISTRYINDEX, (void*)compat53_arith_code);
+  }
+  lua_pushnumber(L, op);
+  lua_pushvalue(L, -4);
+  lua_pushvalue(L, -4);
+  lua_call(L, 3, 1);
+  lua_replace(L, -3); /* replace first operand */
+  lua_pop(L, 1); /* pop second */
+}
+
+
+static const char compat53_compare_code[] = {
+  'l', 'o', 'c', 'a', 'l', ' ', 'o', 'p', ',', 'a', ',', 'b',
+  '=', '.', '.', '.', '\n',
+  'i', 'f', ' ', 'o', 'p', '=', '=', '0', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '=', '=', 'b', '\n',
+  'e', 'l', 's', 'e', 'i', 'f', ' ', 'o', 'p', '=', '=', '1', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '<', 'b', '\n',
+  'e', 'l', 's', 'e', 'i', 'f', ' ', 'o', 'p', '=', '=', '2', ' ',
+  't', 'h', 'e', 'n', '\n',
+  'r', 'e', 't', 'u', 'r', 'n', ' ', 'a', '<', '=', 'b', '\n',
+  'e', 'n', 'd', '\n', '\0'
+};
+
+COMPAT53_API int lua_compare (lua_State *L, int idx1, int idx2, int op) {
+  int result = 0;
+  luaL_checkstack(L, 4, "not enough stack slots");
+  idx1 = lua_absindex(L, idx1);
+  idx2 = lua_absindex(L, idx2);
+  lua_rawgetp(L, LUA_REGISTRYINDEX, (void*)compat53_compare_code);
+  if (lua_type(L, -1) != LUA_TFUNCTION) {
+    lua_pop(L, 1);
+    if (luaL_loadbuffer(L, compat53_compare_code,
+                        sizeof(compat53_compare_code)-1, "=none"))
+      lua_error(L);
+    lua_pushvalue(L, -1);
+    lua_rawsetp(L, LUA_REGISTRYINDEX, (void*)compat53_compare_code);
+  }
+  lua_pushnumber(L, op);
+  lua_pushvalue(L, idx1);
+  lua_pushvalue(L, idx2);
+  lua_call(L, 3, 1);
+  if(lua_type(L, -1) != LUA_TBOOLEAN)
+    luaL_error(L, "invalid 'op' argument for lua_compare");
+  result = lua_toboolean(L, -1);
+  lua_pop(L, 1);
+  return result;
+}
+
+
 COMPAT53_API void lua_copy (lua_State *L, int from, int to) {
   int abs_to = lua_absindex(L, to);
   luaL_checkstack(L, 1, "not enough stack slots");
diff --git a/c-api/compat-5.3.h b/c-api/compat-5.3.h
index b288126..3905a10 100644
--- a/c-api/compat-5.3.h
+++ b/c-api/compat-5.3.h
@@ -40,8 +40,6 @@
 #if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM == 501
 
 /* XXX not implemented:
- * lua_arith
- * lua_compare
  * lua_upvalueid
  * lua_upvaluejoin
  * lua_version
@@ -63,6 +61,16 @@
 #endif
 
 #define LUA_OK 0
+#define LUA_OPADD 0
+#define LUA_OPSUB 1
+#define LUA_OPMUL 2
+#define LUA_OPDIV 3
+#define LUA_OPMOD 4
+#define LUA_OPPOW 5
+#define LUA_OPUNM 6
+#define LUA_OPEQ 0
+#define LUA_OPLT 1
+#define LUA_OPLE 2
 
 typedef struct luaL_Stream {
   FILE *f;
@@ -74,6 +82,12 @@ typedef size_t lua_Unsigned;
 #define lua_absindex COMPAT53_CONCAT(COMPAT53_PREFIX, _absindex)
 COMPAT53_API int lua_absindex (lua_State *L, int i);
 
+#define lua_arith COMPAT53_CONCAT(COMPAT53_PREFIX, _arith)
+COMPAT53_API void lua_arith (lua_State *L, int op);
+
+#define lua_compare COMPAT53_CONCAT(COMPAT53_PREFIX, _compare)
+COMPAT53_API int lua_compare (lua_State *L, int idx1, int idx2, int op);
+
 #define lua_copy COMPAT53_CONCAT(COMPAT53_PREFIX, _copy)
 COMPAT53_API void lua_copy (lua_State *L, int from, int to);
 
diff --git a/tests/test.lua b/tests/test.lua
index b59fd94..2b53b92 100755
--- a/tests/test.lua
+++ b/tests/test.lua
@@ -314,6 +314,15 @@ ___''
 print(mod.absindex("hi", true))
 
 ___''
+print(mod.arith(2, 1))
+print(mod.arith(3, 5))
+
+___''
+print(mod.compare(1, 1))
+print(mod.compare(2, 1))
+print(mod.compare(1, 2))
+
+___''
 print(mod.tolstring("string"))
 local t = setmetatable({}, {
   __tostring = function(v) return "mytable" end
diff --git a/tests/testmod.c b/tests/testmod.c
index a9c8e8d..2c6242b 100644
--- a/tests/testmod.c
+++ b/tests/testmod.c
@@ -96,6 +96,41 @@ static int test_absindex (lua_State *L) {
   return i;
 }
 
+static int test_arith (lua_State *L) {
+  lua_settop(L, 2);
+  lua_pushvalue(L, 1);
+  lua_pushvalue(L, 2);
+  lua_arith(L, LUA_OPADD);
+  lua_pushvalue(L, 1);
+  lua_pushvalue(L, 2);
+  lua_arith(L, LUA_OPSUB);
+  lua_pushvalue(L, 1);
+  lua_pushvalue(L, 2);
+  lua_arith(L, LUA_OPMUL);
+  lua_pushvalue(L, 1);
+  lua_pushvalue(L, 2);
+  lua_arith(L, LUA_OPDIV);
+  lua_pushvalue(L, 1);
+  lua_pushvalue(L, 2);
+  lua_arith(L, LUA_OPMOD);
+  lua_pushvalue(L, 1);
+  lua_pushvalue(L, 2);
+  lua_arith(L, LUA_OPPOW);
+  lua_pushvalue(L, 1);
+  lua_arith(L, LUA_OPUNM);
+  return lua_gettop(L)-2;
+}
+
+static int test_compare (lua_State *L) {
+  luaL_checknumber(L, 1);
+  luaL_checknumber(L, 2);
+  lua_settop(L, 2);
+  lua_pushboolean(L, lua_compare(L, 1, 2, LUA_OPEQ));
+  lua_pushboolean(L, lua_compare(L, 1, 2, LUA_OPLT));
+  lua_pushboolean(L, lua_compare(L, 1, 2, LUA_OPLE));
+  return 3;
+}
+
 static int test_globals (lua_State *L) {
   lua_pushglobaltable(L);
   return 1;
@@ -215,6 +250,8 @@ static const luaL_Reg funcs[] = {
   { "requiref", test_requiref },
   { "getseti", test_getseti },
   { "newproxy", test_newproxy },
+  { "arith", test_arith },
+  { "compare", test_compare },
   { "tonumber", test_tonumber },
   { "tointeger", test_tointeger },
   { "len", test_len },