From 795d1c47a772ec46b34a52e2adf79c323088e55d Mon Sep 17 00:00:00 2001
From: abux <abuxtmk1@gmail.com>
Date: Tue, 28 Jul 2026 11:17:37 +0100
Subject: [PATCH] Allow for use of custom allocators for lua

---
 README.md   |  2 +-
 src/zla.zig | 83 +++++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 75 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index 5af2669..4e70e8a 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 **Simple** 
 ```zig
 // --- ZLA ---
-var zla: Zla = try .init();
+var zla: Zla = try .init(allocator);
 defer zla.deinit();
 
 // --- EXEC FILE ---
diff --git a/src/zla.zig b/src/zla.zig
index 153063c..eee76c4 100644
--- a/src/zla.zig
+++ b/src/zla.zig
@@ -7,11 +7,57 @@ const std = @import("std");
 const lua = @import("luajit");
 const Self = @This();
 
+/// ----------------------------------------------------
+/// ----------------------------------------------------
+const AllocatorUD = struct {
+    alloc: std.mem.Allocator,
+};
+
+/// ----------------------------------------------------
+/// ----------------------------------------------------
+fn luaAlloc(
+    ud: ?*anyopaque,
+    ptr: ?*anyopaque,
+    osize: usize,
+    nsize: usize,
+) callconv(.c) ?*anyopaque {
+    // --- # ---
+    const alloc = @as(
+        *AllocatorUD,
+        @ptrCast(@alignCast(ud)),
+    ).alloc;
+
+    // --- # ---
+    if (nsize == 0) {
+        if (ptr) |p| alloc.free(@as([*]u8, @ptrCast(p))[0..osize]);
+        return null;
+    }
+
+    // --- # ---
+    if (ptr) |p| {
+        return (alloc.realloc(@as([*]u8, @ptrCast(p))[0..osize], nsize) catch {
+            std.debug.print("[LUA_ERROR] Failed to reallocate\n", .{});
+            return null;
+        }).ptr;
+    }
+
+    // --- # ---
+    return (alloc.alloc(
+        u8,
+        nsize,
+    ) catch {
+        std.debug.print("[LUA_ERROR] Failed to allocate\n", .{});
+        return null;
+    }).ptr;
+}
+
 //
 // FIELDS
 //
 
 state: *lua.lua_State,
+alloc: std.mem.Allocator,
+alloc_ud: *AllocatorUD,
 err: ?[*:0]const u8 = null,
 
 //
@@ -20,16 +66,34 @@ err: ?[*:0]const u8 = null,
 
 /// ----------------------------------------------------
 /// ----------------------------------------------------
-pub fn init() !Self {
-    const state = lua.luaL_newstate() orelse return error.LuaStateFailed;
-    lua.luaL_openlibs(state);
-    return .{ .state = state };
+pub fn init(alloc: std.mem.Allocator) !Self {
+    // --- CREATE NEW ALLOCATOR ---
+    const ud = try alloc.create(AllocatorUD);
+    ud.* = .{ .alloc = alloc };
+
+    // --- NEW LUA STATE ---
+    const state = lua.lua_newstate(luaAlloc, ud) orelse {
+        alloc.destroy(ud);
+        return error.LuaStateFailed;
+    };
+
+    // --- OPEN LIBS ---
+    lua.luaL_openlibs(
+        state,
+    );
+
+    return .{
+        .state = state,
+        .alloc = alloc,
+        .alloc_ud = ud,
+    };
 }
 
 /// ----------------------------------------------------
 /// ----------------------------------------------------
 pub fn deinit(self: *Self) void {
     lua.lua_close(self.state);
+    self.alloc.destroy(self.alloc_ud);
 }
 
 //
@@ -313,7 +377,7 @@ pub fn register(
 
     const Wrapper = struct {
         fn luaFunc(state: ?*lua.lua_State) callconv(.c) c_int {
-            var zl = Self{ .state = state.? };
+            var zl = Self{ .state = state.?, .alloc = undefined, .alloc_ud = undefined };
 
             const args: std.meta.ArgsTuple(@TypeOf(func)) = args: {
                 var a: std.meta.ArgsTuple(@TypeOf(func)) = undefined;
@@ -350,7 +414,7 @@ pub fn registerWithCtx(
     // --- # ---
     const Wrapper = struct {
         fn luaFunc(state: ?*lua.lua_State) callconv(.c) c_int {
-            var zl = Self{ .state = state.? };
+            var zl = Self{ .state = state.?, .alloc = undefined, .alloc_ud = undefined };
 
             // --- # ---
             const ctx_ptr: CtxType = @ptrCast(@alignCast(
@@ -444,7 +508,7 @@ pub fn registerMethods(
         const Wrapper = struct {
             fn luaFunc(state: ?*lua.lua_State) callconv(.c) c_int {
                 // --- # ---
-                var zl = Self{ .state = state.? };
+                var zl = Self{ .state = state.?, .alloc = undefined, .alloc_ud = undefined };
                 const args: std.meta.ArgsTuple(@TypeOf(func)) = args: {
                     // --- # ---
                     var a: std.meta.ArgsTuple(@TypeOf(func)) = undefined;
@@ -461,6 +525,7 @@ pub fn registerMethods(
                     // --- # ---
                     break :args a;
                 };
+
                 // --- # ---
                 const ret = @call(.auto, func, args);
                 if (Return == void) return 0;
@@ -555,7 +620,7 @@ test "exec" {
     std.debug.print("\x1b[34m<--- EXEC --->\x1b[0m\n", .{});
 
     // --- ZLA ---
-    var zla: Self = try .init();
+    var zla: Self = try .init(std.testing.allocator);
     defer zla.deinit();
 
     // --- EXEC FILE ---
@@ -576,7 +641,7 @@ test "userdata" {
     std.debug.print("\x1b[34m<--- USERDATA --->\x1b[0m\n", .{});
 
     // --- ZLA ---
-    var zla: Self = try .init();
+    var zla: Self = try .init(std.testing.allocator);
     defer zla.deinit();
 
     // --- APP ---