From b23728f52550a40c4a1d19f28268fd49c1e6fbde Mon Sep 17 00:00:00 2001
From: Josh Yelon <jyelon@gmail.com>
Date: Sun, 28 Feb 2021 14:24:59 -0500
Subject: [PATCH] still working on porting to lua 5.2

---
 luprex/core/cpp/luaconsole.cpp |  2 +-
 luprex/core/cpp/luastack.cpp   | 39 +++++++++++++++++-----------------
 luprex/core/cpp/luastack.hpp   |  6 +++---
 3 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/luprex/core/cpp/luaconsole.cpp b/luprex/core/cpp/luaconsole.cpp
index 54956aec..1595dab8 100644
--- a/luprex/core/cpp/luaconsole.cpp
+++ b/luprex/core/cpp/luaconsole.cpp
@@ -9,7 +9,7 @@ static bool is_single_letter(const std::string &s) {
 }
 
 LuaConsole::LuaConsole() {
-    lua_state_ = lua_open();
+    lua_state_ = luaL_newstate();
     clear();
 }
 
diff --git a/luprex/core/cpp/luastack.cpp b/luprex/core/cpp/luastack.cpp
index 5c93f9ef..a59c3991 100644
--- a/luprex/core/cpp/luastack.cpp
+++ b/luprex/core/cpp/luastack.cpp
@@ -3,7 +3,6 @@
 #include <iostream>
 
 LuaSpecial LuaRegistry(LUA_REGISTRYINDEX);
-LuaSpecial LuaGlobals(LUA_GLOBALSINDEX);
 LuaNilMarker LuaNil;
 LuaNewTableMarker LuaNewTable;
 
@@ -39,8 +38,8 @@ lua_Number LuaStack::cknumber(LuaSlot s) const {
 std::string LuaStack::ckstring(LuaSlot s) const {
     luaL_checktype(L_, s, LUA_TSTRING);
     size_t len;
-    const char *s = lua_tolstring(L_, s, &len);
-    return std::string(s, len);
+    const char *str = lua_tolstring(L_, s, &len);
+    return std::string(str, len);
 }
 
 lua_State *LuaStack::ckthread(LuaSlot s) const {
@@ -104,12 +103,6 @@ void LuaStack::pop_any_value(std::string &s) const {
     lua_pop(L_, 1);
 }
 
-std::string LuaStack::ckstring(LuaSlot s) const {
-    size_t len;
-    const char *str = luaL_cklstring(L_, s, &len);
-    return std::string(str, len);
-}
-
 void LuaStack::clearmetatable(LuaSlot tab) const {
     lua_pushnil(L_);
     lua_setmetatable(L_, tab);
@@ -156,29 +149,37 @@ lua_State *LuaStack::newthread(LuaSlot target) const {
 }
 
 void LuaStack::makeclass(LuaSlot classtab, LuaSlot classname) const {
-    checkstring(classname);
+    LuaVar globtab;
+    LuaStack LS(L_, globtab);
 
-    // Special case: if the classname is _G, detect and error.
-    if (equal(classname, "_G")) {
+    // Validate the class name.
+    LS.checkstring(classname);
+    if (LS.equal(classname, "_G")) {
         luaL_error(L_, "_G is explicitly not allowed as a class name");
     }
+
+    // Fetch the global environment from the registry.
+    LS.rawget(globtab, LuaRegistry, LUA_RIDX_GLOBALS);
     
     // Get the classtab from the global environment.
     // Create it if it doesn't exist.
-    rawget(classtab, LuaGlobals, classname);
-    if (isnil(classtab)) {
-        newtable(classtab);
-        rawset(LuaGlobals, classname, classtab);
+    LS.rawget(classtab, globtab, classname);
+    if (LS.isnil(classtab)) {
+        LS.newtable(classtab);
+        LS.rawset(globtab, classname, classtab);
     }
 
     // If the name isn't bound to a table, abort.
-    if (!istable(classtab)) {
+    if (!LS.istable(classtab)) {
         luaL_error(L_, "%s is not a class", ckstring(classname).c_str());
     }
 
     // Repair the special fields.
-    rawset(classtab, "__index", classtab);
-    rawset(classtab, "__class", classname);
+    LS.rawset(classtab, "__index", classtab);
+    LS.rawset(classtab, "__class", classname);
+
+    // Put the stack back.
+    LS.result();
 }
 
 void LuaStack::makesubtable(LuaSlot sub, LuaSlot tab, const char *name) const {
diff --git a/luprex/core/cpp/luastack.hpp b/luprex/core/cpp/luastack.hpp
index b1878346..3e048688 100644
--- a/luprex/core/cpp/luastack.hpp
+++ b/luprex/core/cpp/luastack.hpp
@@ -156,6 +156,7 @@
 
 extern "C" {
 #include "lua.h"
+#include "lauxlib.h"
 }
 
 #include <string>
@@ -192,7 +193,6 @@ public:
 };
 
 extern LuaSpecial LuaRegistry;
-extern LuaSpecial LuaGlobals;
 
 class LuaUpvalue : public LuaSlot {
     public:
@@ -404,12 +404,12 @@ public:
     }
 
     bool equal(LuaSlot v1, LuaSlot v2) const {
-        return lua_equal(L_, v1, v2);
+        return lua_compare(L_, v1, v2, LUA_OPEQ);
     }
 
     bool equal(LuaSlot v1, const char *name) const {
         push_any_value(name);
-        bool result = lua_equal(L_, v1, -1);
+        bool result = lua_compare(L_, v1, -1, LUA_OPEQ);
         lua_pop(L_, 1);
         return result;
     }