Automatically autoload all constants for a module.
Reduces your requires to one line per file, plus external dependencies.
Enables requiring always only the precise file holding the constant you depend on (or top level if you depend on many).

gem install zeroload

Map your constants to filenames by replacing :: with /. For example, the constant Foo::BarBaz should be defined in file lib/Foo/BarBaz.rb. Note that the case matters! Each file should require the nesting namespace. That is, Foo/BarBaz.rb should require "Foo". All modules & classes always use zeroload.

Given the files

• lib/Foo.rb
• lib/Foo/Bar.rb

The contents of lib/Foo.rb is:

require "Zeroload"

module Foo
  zeroload!

  # Code of Foo
end

And the contents of lib/Foo/bar.rb is:

require "Foo"

module Foo
  class Bar
    zeroload! # only necessary if there's stuff nested below 

    # Code of Foo::Bar
  end
end

Automatically autoload all constants for a module. This requires a change from the current convention of putting class Foo::BarBaz into foo/barbaz.rb (or foo/bar_baz.rb in rails) to using Foo/BarBaz.rb instead.

• Q: But didn't have Kernel#autoload problems with multi-threading?
• A: Yes, it did. They've since been resolved:
  • see bug 921
  • see Revision 33078
• Q: But isn't Kernel#autoload deprecated?
• A: Sadly, the state on this is not entirely clear. But it seems it is no longer deprecated.
• Q: But with autoloaded constants, Module#constants will not report all constants.
• A: That is not correct. Autoloaded (but not yet loaded) constants show up with Module#constants. But you can also use Zeroconf.preload! to load all constants at once.