optarg

Yet another library for parsing command-line options and arguments, written in the Crystal language.

Installation

Add this to your application's shard.yml:

dependencies:
  optarg:
    github: mosop/optarg

Features

• Easy Access

  class Model < Optarg::Model
    string "--foo"
  end
  
  result = Model.parse(%w(--foo bar))
  result.foo # => "bar"
  

• Nilable Accessor

  class Model < Optarg::Model
    string "--foo"
  end
  
  result = Model.parse(%w())
  result.foo? # => nil
  result.foo # raises KeyError
  

• Synonyms

  class Model < Optarg::Model
    string %w(-f --file)
  end
  
  result = Model.parse(%w(-f foo.cr))
  result.f # => "foo.cr"
  result.file # => "foo.cr"
  

• Default Value

  class Model < Optarg::Model
    string "--foo", default: "bar"
  end
  
  result = Model.parse(%w())
  result.foo # => "bar"
  

• Boolean Value

  class Model < Optarg::Model
    bool "-b"
  end
  
  result = Model.parse(%w(-b))
  result.b? # => true
  

• Negation

  class Model < Optarg::Model
    bool "-b", not: "-B"
  end
  
  result = Model.parse(%w(-B))
  result.b? # => false
  

• Non-defined Arguments

  class Model < Optarg::Model
    string "-s"
    bool "-b"
  end
  
  result = Model.parse(%w(-s foo -b bar -- baz))
  result.args # => ["bar"]
  result.unparsed_args # => ["baz"]
  

• Inheritance (Reusable Model)

  class Animal < Optarg::Model
    bool "--sleep"
  end
  
  class Cat < Animal
    bool "--mew"
  end
  
  class Dog < Animal
    bool "--woof"
  end
  
  cat = Cat.parse(%w(--sleep --mew))
  dog = Dog.parse(%w(--sleep --woof))
  

• Handler

  class Model < Optarg::Model
    on("--goodbye") { world! }
  
    def world!
      raise "Goodbye, world!"
    end
  end
  
  Model.parse %w(--goodbye) # raises "Goodbye, world!"
  

• Custom Initializer

  class The
    def message
      "Someday again!"
    end
  end
  
  class Model < Optarg::Model
    def initialize(argv, @the : The)
      super argv
    end
  
    on("--goodbye") { raise @the.message }
  end
  
  Model.new(%w(--goodbye), The.new).parse # raises "Someday again!"
  

• [WIP] Documentation

Usage

require "optarg"

and see Features.

Releases

• v0.1.3
  • Custom Initializer
• v0.1.2
  • Synonyms
• v0.1.1
  • Handler

Development

[WIP]

Contributing

1. Fork it ( https://github.com/mosop/optarg/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

• mosop - creator, maintainer