Add support for lua.pushValue()

Author: thsackos

README.md

@@ -160,7 +160,7 @@ pattern has changed, such as using the Zig `init()` function pattern instead of
 | `lua_pushnumber`| ☑️ `lua.pushNumber()` |
 | `lua_pushstring`| ☑️ `lua.pushString()` |
 | `lua_pushthread`||
-| `lua_pushvalue`||
+| `lua_pushvalue`| ☑️ `lua.pushValue()` |
 | `lua_pushvfstring`||
 | `lua_rawequal`||
 | `lua_rawgeti`||

src/lua_api.zig

@@ -95,13 +95,6 @@ pub fn pushLiteral(lua: *Lua, s: []const u8) void;
 /// Stack Behavior: `[-0, +1, -]`
 pub fn pushThread(lua: *Lua) bool;
 
-/// Pushes a copy of the element at the given valid index onto the stack.
-///
-/// From: `void lua_pushvalue(lua_State *L, int index);`
-/// Refer to: https://www.lua.org/manual/5.1/manual.html#lua_pushvalue
-/// Stack Behavior: `[-0, +1, -]`
-pub fn pushValue(lua: *Lua, index: i32) void;
-
 /// Equivalent to pushFString, except that it receives a va_list instead of a variable number of arguments.
 ///
 /// From: `const char *lua_pushvfstring(lua_State *L, const char *fmt, va_list argp);`

src/root.zig

@@ -703,6 +703,15 @@ pub const Lua = opaque {
         return @ptrCast(c.lua_touserdata(asState(lua), index));
     }
 
+    /// Pushes a copy of the element at the given valid index onto the stack.
+    ///
+    /// From: `void lua_pushvalue(lua_State *L, int index);`
+    /// Refer to: https://www.lua.org/manual/5.1/manual.html#lua_pushvalue
+    /// Stack Behavior: `[-0, +1, -]`
+    pub fn pushValue(lua: *Lua, index: i32) void {
+        return c.lua_pushvalue(asState(lua), index);
+    }
+
     /// Pushes the zero-terminated string onto the stack. Lua makes (or reuses) an internal copy of the given string,
     /// so the provided slice can be freed or reused immediately after the function returns. The given string cannot
     /// contain embedded zeros; it is assumed to end at the first zero (`'\x00'`) byte.
@@ -2309,3 +2318,25 @@ test "push and get light userdata" {
     try std.testing.expectEqual(a1.?, @as(*anyopaque, @ptrCast(&i)));
     try std.testing.expectEqual(a1.?, a2.?);
 }
+
+test "pushvalue" {
+    const lua = try Lua.init(std.testing.allocator);
+    defer lua.deinit();
+
+    lua.pushInteger(42);
+    lua.pushValue(-1);
+    try std.testing.expect(lua.equal(-1, -2));
+
+    const a1 = lua.toInteger(-1);
+    const a2 = lua.toInteger(-2);
+    try std.testing.expectEqual(a1, a2);
+
+    lua.setTop(0);
+    lua.pushLString("ASDF");
+    lua.pushValue(-1);
+    try std.testing.expect(lua.equal(-1, -2));
+
+    const s1 = try lua.toLString(-1);
+    const s2 = try lua.toLString(-2);
+    try std.testing.expectEqualStrings(s1, s2);
+}