README.md

Lua WASM Bindings

WASM bindings and binaries for 5.4.6

Building

• Install emscripten using your native package manager (eg pacman, apt, brew, etc ...)
  • https://emscripten.org/index.html
• Run ./scripts/setup.sh
• Run npm run build (or whatever JS build system you use)

Important

The binding script doesn't include the entire Lua API, some effort might be needed to add missing features. For the complete Lua API reference, visit https://www.lua.org/manual/5.4/manual.html

Example

import { LUA_OK } from "lua-wasm-bindings/dist/lua";

import { lauxlib, lua, lualib } from "lua-wasm-bindings/dist/lua.54";

const luaCode = `return "Hello"`;
consol.log(executeLua(luaCode));

function executeLua(luaCode: string): string | Error | never {
  const L = lauxlib.luaL_newstate();
  lualib.luaL_openlibs(L);

  // Optional Load modules
  // lua.lua_getglobal(L, "package");
  // lua.lua_getfield(L, -1, "preload");
  // lauxlib.luaL_loadstring(L, jsonLib); // Load extenal package from string
  // lua.lua_setfield(L, -2, "json");

  const status = lauxlib.luaL_dostring(L, luaCode);

  if (status === LUA_OK) {
    if (lua.lua_isstring(L, -1)) {
      const result = lua.lua_tostring(L, -1);
      lua.lua_close(L);
      return result === null ? undefined : result;
    } else {
      const returnType = lua.lua_typename(L, lua.lua_type(L, -1));
      lua.lua_close(L);
      throw new Error(`Unsupported Lua return type: ${returnType}`);
    }
  } else {
    const luaStackString = lua.lua_tostring(L, -1);
    const message = luaStackString.replace(/^\[string "(--)?\.\.\."\]:\d+: /, "");
    lua.lua_close(L);
    return new Error(message);
  }
}