include_enum

A tiny Crystal shard that lets you use an enum's values as local constants without the EnumType:: prefix. An optional prefix string can be added to each constant name to avoid collisions.

Installation

Add the dependency to your shard.yml:

dependencies:
  include_enum:
    github: plambert/include_enum.cr

Then run shards install.

Usage

require "include_enum"

enum Color
  Red
  Green
  Blue
end

Include the module, then call the macro

class Palette
  include IncludeEnum
  include_enum Color

  # Red, Green, and Blue are now available as constants:
  def default
    Green
  end
end

Call the macro directly (no include needed)

class Palette
  IncludeEnum.include_enum Color

  def default
    Green
  end
end

Add a prefix to avoid name collisions

class Palette
  IncludeEnum.include_enum Color, "C_"

  # Constants are now C_Red, C_Green, C_Blue:
  def default
    C_Green
  end
end

Include only specific values

class Palette
  include IncludeEnum
  include_enum Color, only: {Red, Blue}

  # Only Red and Blue are available; Green is not.
end

Exclude specific values

class Palette
  include IncludeEnum
  include_enum Color, except: {Green}

  # Red and Blue are available; Green is not.
end

only and except are mutually exclusive — using both raises a compile-time error.

What gets generated

The macro expands to simple constant assignments:

Red   = Color::Red
Green = Color::Green
Blue  = Color::Blue

Or with a prefix of "C_":

C_Red   = Color::Red
C_Green = Color::Green
C_Blue  = Color::Blue

Contributing

1. Fork it (https://github.com/plambert/include_enum.cr/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Paul M. Lambert - creator and maintainer