public MondValue Require(MondState state, string fileName) { if (_require.Loader == null) throw new MondRuntimeException("require: module loader is not set"); const string cacheObjectName = "__modules"; MondValue cacheObject; // make sure we have somewhere to cache modules if (state[cacheObjectName].Type != MondValueType.Object) { cacheObject = new MondValue(state); cacheObject.Prototype = MondValue.Null; state[cacheObjectName] = cacheObject; } else { cacheObject = state[cacheObjectName]; } // return cached module if it exists var cachedExports = cacheObject[fileName]; if (cachedExports.Type == MondValueType.Object) return cachedExports; // create a new object to store the exports var exports = new MondValue(state); exports.Prototype = MondValue.Null; // instantly cache it so we can have circular dependencies cacheObject[fileName] = exports; try { var searchDirectories = new[] { Path.GetDirectoryName(state.CurrentScript), "" }; var moduleSource = _require.Loader(fileName, searchDirectories.AsReadOnly()); // wrap the module script in a function so we can pass out exports object to it var source = _require.Definitions + "return fun (exports) {\n" + moduleSource + " return exports; };"; var options = new MondCompilerOptions { FirstLineNumber = -1 }; var requireOptions = _require.Options; if (requireOptions != null) { options.DebugInfo = requireOptions.DebugInfo; options.MakeRootDeclarationsGlobal = requireOptions.MakeRootDeclarationsGlobal; options.UseImplicitGlobals = requireOptions.UseImplicitGlobals; } var program = MondProgram.Compile(source, fileName, options); var initializer = state.Load(program); var result = state.Call(initializer, exports); if (result.Type != MondValueType.Object) throw new MondRuntimeException("require: module must return an object (`{0}`)", fileName); if (!ReferenceEquals(exports, result)) { // module returned a different object, merge with ours foreach (var kv in result.Object) { var key = kv.Key; var value = kv.Value; exports[key] = value; } exports.Prototype = result.Prototype; if (result.IsLocked) exports.Lock(); } } catch { // if something goes wrong, remove the entry from the cache cacheObject[fileName] = MondValue.Undefined; throw; } return exports; }