flua/lib/index.js

Easy scriptable Lua in the browser with fengari.

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

exports.run = run;
exports.runWithGlobals = runWithGlobals;
exports.flua_setglobals = flua_setglobals;
exports.flua_getglobals = flua_getglobals;
exports.flua_getfullstack = flua_getfullstack;
exports.flua_readany = flua_readany;
exports.flua_readtable = flua_readtable;
exports.flua_pushobject = flua_pushobject;
exports.flua_pusharray = flua_pusharray;
exports.flua_pushany = flua_pushany;
/** @format */

var fengari = require('fengari');

var lua = fengari.lua;
var lauxlib = fengari.lauxlib;
var lualib = fengari.lualib;

var LUA_TBOOLEAN = lua.LUA_TBOOLEAN,
    LUA_TFUNCTION = lua.LUA_TFUNCTION,
    LUA_TNIL = lua.LUA_TNIL,
    LUA_TNUMBER = lua.LUA_TNUMBER,
    LUA_TSTRING = lua.LUA_TSTRING,
    LUA_TTABLE = lua.LUA_TTABLE,
    lua_gettop = lua.lua_gettop,
    lua_isnone = lua.lua_isnone,
    lua_pop = lua.lua_pop,
    lua_createtable = lua.lua_createtable,
    lua_next = lua.lua_next,
    lua_pushboolean = lua.lua_pushboolean,
    lua_pushjsfunction = lua.lua_pushjsfunction,
    lua_pushnil = lua.lua_pushnil,
    lua_pushnumber = lua.lua_pushnumber,
    lua_pushstring = lua.lua_pushstring,
    lua_rawlen = lua.lua_rawlen,
    lua_rawgeti = lua.lua_rawgeti,
    lua_rawseti = lua.lua_rawseti,
    lua_rawget = lua.lua_rawget,
    lua_rawset = lua.lua_rawset,
    lua_setglobal = lua.lua_setglobal,
    lua_getglobal = lua.lua_getglobal,
    lua_toboolean = lua.lua_toboolean,
    lua_tojsstring = lua.lua_tojsstring,
    lua_tonumber = lua.lua_tonumber,
    lua_tointeger = lua.lua_tointeger,
    lua_type = lua.lua_type;

// utils

function run(code, getglobals) {
  runWithGlobals({}, code, getglobals);
}

function runWithGlobals(globals, code) {
  var getglobals = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : [];

  var L = lauxlib.luaL_newstate();
  lualib.luaL_openlibs(L);
  flua_setglobals(L, globals);
  var bad = lauxlib.luaL_loadstring(L, fengari.to_luastring(code));
  if (bad) {
    throw new Error(bad);
  }
  var err = lua.lua_pcall(L, 0, 0, 0);
  if (err) {
    var errmsg = lua_tojsstring(L, -1);
    lua_pop(L, 1);
    throw new Error(errmsg);
  }
  return flua_getglobals(L, getglobals);
}

function flua_setglobals(L, globals) {
  for (var k in globals) {
    var v = globals[k];
    flua_pushany(L, v);
    lua_setglobal(L, k);
  }
}

function flua_getglobals(L, names) {
  var globals = {};
  for (var i = 0; i < names.length; i++) {
    var name = names[i];
    lua_getglobal(L, name);
    var v = flua_readany(L, -1);
    globals[name] = v;
    lua_pop(L, 1);
  }
  return globals;
}

function flua_getfullstack(L) {
  values = [];
  for (var i = 1; i <= lua_gettop(L); i++) {
    var v = flua_readany(L, i);
    values.push(v);
  }
  return values;
}

// read stuff
function flua_readany(L, pos) {
  switch (lua_type(L, pos)) {
    case LUA_TNIL:
      return null;
    case LUA_TNUMBER:
      return lua_tonumber(L, pos);
    case LUA_TBOOLEAN:
      return lua_toboolean(L, pos);
    case LUA_TSTRING:
      var x = lua_tojsstring(L, pos);
      return x;
    case LUA_TTABLE:
      return flua_readtable(L, pos);
  }
  return null;
}

function flua_readtable(L, pos) {
  if (pos < 0) {
    pos = lua_gettop(L) + 1 + pos;
  }

  var object = {};
  var slice = [];

  var isArray = true;
  var size = lua_rawlen(L, pos);
  if (size === 0) {
    isArray = false;
  } else {
    slice = new Array(size);
  }

  lua_pushnil(L);
  while (lua_next(L, pos) !== 0) {
    var val = flua_readany(L, -1);
    lua_pop(L, 1);

    // array
    if (isArray) {
      var index = lua_tointeger(L, -1);
      if (index !== 0 && index <= size) {
        slice[index - 1] = val;
      } else {
        isArray = false;
      }
    }

    // object
    var key = '' + flua_readany(L, -1);
    object[key] = val;
  }

  return isArray ? slice : object;
}

// push stuff
function flua_pushobject(L, obj) {
  lua_createtable(L, 0, Object.keys(obj).length);
  for (var k in obj) {
    var v = obj[k];
    flua_pushany(L, k);
    flua_pushany(L, v);
    lua_rawset(L, -3);
  }
}

function flua_pusharray(L, s) {
  lua_createtable(L, s.length, 0);
  for (var i = 0; i < s.length; i++) {
    var v = s[i];
    flua_pushany(L, v);
    lua_rawseti(L, -2, i + 1);
  }
}

function flua_pushany(L, val) {
  switch (typeof val === 'undefined' ? 'undefined' : _typeof(val)) {
    case 'string':
      lua_pushstring(L, val);
      break;
    case 'number':
      lua_pushnumber(L, val);
      break;
    case 'boolean':
      lua_pushboolean(L, val);
      break;
    case 'object':
      if (Array.isArray(val)) {
        flua_pusharray(L, val);
      } else if (val === null) {
        lua_pushnil(L);
      } else {
        flua_pushobject(L, val);
      }
      break;
    case 'function':
      lua_pushjsfunction(L, function (L) {
        var n = lua_gettop(L);
        var args = new Array(n);
        for (var i = 1; i <= n; i++) {
          args[i - 1] = flua_readany(L, i);
        }

        var returned = val.apply(null, args);
        returned = returned === null ? [] : Array.isArray(returned) ? returned : [returned];

        for (var _i = 0; _i < returned.length; _i++) {
          flua_pushany(L, returned[_i]);
        }

        return returned.length;
      });
      break;
    default:
      lua_pushnil(L);
      break;
  }
}