ch1c0t / bgem

To make Ruby gems from macros

Introduction

Bgem is a tool to build Ruby gems with less ends. It is available on RubyGems as bgem.

When you have to put your code inside of a nested namespace, it could be tedious. In each file, you have to enclose it. For example, in lib/m/c/nested_code you would have:

module M
  class C
    module NestedCode
      def some_method
      end
    end
  end
end

Without Bgem: the more files you have, the more times you have to repeat

module M
  class C
    # your code
  end
end

With Bgem: you can add bgem/config.rb

output 'lib/m/c/nested_code.rb'
inside 'class C', 'module M'

and src/NestedCode.module.rb

def some_method
end

and then, when you run bundle exec bgem, a single-file gem will be created at lib/m/c/nested_code.rb.

Directory structure

Bgem derives how to nest the code from its directory structure in src. Since Bgem is built with Bgem, we can use its code as a usage example.

tree --charset=ascii src:

src
|-- Bgem
|   |-- Config.class.rb
|   |-- Output.class.rb
|   |-- pre.Output
|   |   |-- Ext
|   |   |   |-- RB
|   |   |   |   |-- Class.class.rb
|   |   |   |   `-- Module.class.rb
|   |   |   `-- RB.module.rb
|   |   |-- Ext.class.rb
|   |   `-- pre.Ext
|   |       `-- StandardHooks.module.rb
|   `-- Write.class.rb
`-- Bgem.module.rb

5 directories, 9 files

There are src/Bgem.module.rb file and src/Bgem directory, containing the code that all will end up in one file lib/bgem.rb if you run bundle exec bgem.

Each file inside src must follow the naming convention Name.type.rb. type could be either class or module. Name should start with a big letter since it will be either class or module name.

Each file can have a corresponding directory(for Name.type.rb it would be Name; for Bgem.module.rb it is Bgem). The code from this directory is added after the code from the file:

module Bgem
  # code from Bgem.module.rb

  # code from Bgem directory
end

If it would be needed, it also could have a corresponding directory for the code that would be added before the code from the file. It would be called pre.Bgem:

module Bgem
  # code from pre.Bgem directory

  # code from Bgem.module.rb

  # code from Bgem directory
end

More usage examples

If you would like, you can take a look at

• https://github.com/ch1c0t/hobby-json-keys/blob/main/bgem/config.rb
• https://github.com/ch1c0t/hobby-rpc/blob/main/bgem/config.rb

Any feedback is welcome. Please feel free to reach me out by email([e-mail]) or open an issue.

Development

To build the project and run the specs:

bundle exec rake