Issue #14982 has been updated by shioyama (Chris Salzberg). For those following this issue, it is now possible in Ruby 3.2. to write autoloaded code that does not touch the global namespace, with Im, a fork of Zeitwerk I have been working on over the past couple months: https://github.com/shioyama/im Im relies on two new features in 3.2: `Kernel#load` with a module as second argument, and `Module#const_added`. Further details are provided in the readme, but the tl;dr is that it provides an interface almost identical to Zeitwerk, but rather than autoloading to `Object` it autoloads to an anonymous module (an instance of `Im::Loader`, which is a subclass of `Module`.) I have also developed a demo Rails app which uses Im to load the entire application onto a single namespace, while allowing you to actually write the code as you normally would, at toplevel. https://github.com/shioyama/rails_on_im ---------------------------------------- Feature #14982: Improve namespace system in ruby to avoiding top-level names chaos https://bugs.ruby-lang.org/issues/14982#change-101819 * Author: jjyr (Jinyang Jiang) * Status: Open * Priority: Normal * Assignee: matz (Yukihiro Matsumoto) ---------------------------------------- Updated: https://bugs.ruby-lang.org/issues/14982#note-5 ## Why Ruby has evaluation all class/module names in top-level context(aka TOPLEVEL_BINDING). As a user we basically hard to know how many names in the current context, is causing chaos in some cases. For example: case 1: Put common used errors class in a single file, like below ``` ruby # utils/errors.rb class FooError end class BarError end ``` In other files under 'utils' we want to use those errors, so the best practice is to use `require_relative 'errors'` in each file we need. ``` ruby # utils/binary_helper.rb # we forget require errors module BinaryHelper # ... raise BarError # ... end ``` But sometime we may forget to require dependencies in a file, it's hard to notice because if RubyVM already execute the requires we still can access the name BarError, but if user directly to require 'utils/binary_helper', he/she will got an NameError. case 2: Two gems use same top-level module name, so we can't use them together ## The Reason of The Problem The reason is we let module author to decision which module user can use. ('require' is basically evaluation, highly dependent on the module author's design) But we should let users control which names to use and available in context. As many other popular languages dose(Rust, Python..) I think the solution is basically the same philosophy compares to refinement feature. ## The Design I propose an improved namespace to Ruby, to solve the problems and still compatible with the current Ruby module system. ``` ruby class Foo end # introduce Kernel#namespace namespace :Hello do # avoiding namespace chaos # Foo -> NameError, can't access TOPLEVEL_BINDING directly # Kernel#import method, introduce Foo name from TOPLEVEL_BINDING import :Foo # in a namespace user can only access imported name Foo # import constant to another alias name # can avoid writing nested module/class names import :"A::B::C::D", as: :E # require then import, for convenient import :"A::B::C::D", as: :E, from: 'some_rb_file' # import same name from two gems import :"Foo", as: :Foo_A, from: 'foo_a' import :"Foo", as: :Foo_B, from: 'foo_b' # import names in batch import %i{"A::B::C::D", "AnotherClass"}, from: 'some_rb_file' # import and alias in batch import {:"A::B::C::D" => :E, :Foo => Foo2}, from: 'some_rb_file' class Bar def xxx # can access all names in namespace scope [Foo, Foo_A, Foo_B] end end end Hello.class # -> module. namespace is just a module Hello::Bar # so we do not broken current ruby module design # namespace system is intent to let user to control names in context # So user can choose use the old require way require 'hello' Hello::Bar # Or user can use namespace system as we do in hello.rb namespace :Example do import :"Hello::Bar", as: :Bar Bar # ok Foo # name error, cause we do not import Foo in :Example namespace end Foo # ok, cause Foo is loaded in TOPLEVEL_BINDING # define nested namespace # more clear syntax than “module Example::NestedExample” namespace :NestedExample, under: Example do end namespace :Example2 do namespace :NestedExample do end end ``` Pros: * Completely compatible with the current module system, a gem user can completely ignore whether a gem is write in Namespace or not. * User can completely control which names in current context/scope. * May solve the top module name conflict issue(depends on VM implementation). * Avoid introducing new keyword and syntax. * Type hint or name hint can be more accuracy under namespace(not sure). Cons: * Need to modify Ruby VM to support the feature. -- https://bugs.ruby-lang.org/