Matchete

Matchete provides a DSL for method overloading based on pattern matching for Ruby.

It's just a quick hack inspired by weissbier and the use-return-values-of-method-definitions DSL technique used in harmonic

Install

gem install matchete

Usage

require 'matchete'

class FactorialStrikesAgain
  include Matchete

  on 1,
  def factorial(value)
    1
  end

  on -> x { x > 1 },
  def factorial(value)
    value * factorial(value - 1)
  end
end

FactorialStrikesAgain.new.factorial(4) #24
FactorialStrikesAgain.new.factorial(-2) #Matchete::NotResolvedError No matching factorial method for args [-2]

require 'matchete'

class Converter
  include Matchete

  on Integer,
  def convert(value)
    [:integer, value]
  end

  on Hash,
  def convert(values)
    [:dict, values.map { |k, v| [convert(k), convert(v)] }]
  end

  on /reserved_/,
  def convert(value)
    [:reserved_symbol, value]
  end

  on String,
  def convert(value)
    [:string, value]
  end

  on ['deleted', [Integer, Any]],
  def convert(value)
    ['deleted', value[1]]
  end

  on :not_implemented?,
  def convert(value)
    [:fail, value]
  end

  on free: Integer, method:
  def convert(free:)
    [:rofl, free]
  end

  default def convert(value)
    [:z, value]
  end

  def not_implemented?(value)
    value.is_a? Symbol
  end
end

converter = Converter.new
p converter.convert(2) #[:integer, 2]
p converter.convert({2 => 4}) #[:dict, [[[:integer, 2], [:integer, 4]]]
p converter.convert('reserved_l') #[;reserved_symbol, 'l']
p converter.convert('zaza') #[:string, 'zaza']
p converter.convert(['deleted', [2, Array]]) #['deleted', [2, Array]]
p converter.convert(:f) #[:fail, :f]
p converter.convert(free: 2) #[:rofl, 2]
p converter.convert(2.2) #[:z, 2.2]

Todo

Copyright

Copyright (c) 2014 Alexander Ivanov. See LICENSE for further details.