Rebuilding Inquisitio

nice_and_simple.rb

class Inquisitio
 
  attr_reader :criteria, :limit, :order
 
  def initialize
    @criteria = []
    @limit = 10
 
    yield(self) if block_given?
  end
 
  def self.method_missing(name, *args)
    new.send(name, *args)
  end
 
  def where(criteria)
    clone { |i| i.criteria << criteria }
  end
 
  def limit(limit)
    clone { |i| i.limit = limit }
  end
 
  def order(order)
    clone { |i| i.order = order }
  end
 
  protected
  attr_writer :criteria, :limit, :order
 
  def clone
    Inquisitio.new do |i|
      i.instance_variable_set(:@criteria, @criteria)
      i.instance_variable_set(:@limit, @limit)
      i.instance_variable_set(:@order, @order)
      yield i
    end
  end
 
end
 
thing = Inquisitio.where(x: true).limit(5).order('foobar desc')
thing = thing.where(y: false)
p thing

taking_it_meta.rb

class Inquisitio
 
  ArrayAttrs = {criteria: :where}
  ObjectAttrs = [:limit, :order]
 
  attr_reader *ArrayAttrs.keys
  attr_reader *ObjectAttrs
 
  def initialize
    @criteria = []
    @limit = 10
 
    yield(self) if block_given?
  end
 
  def self.method_missing(name, *args)
    new.send(name, *args)
  end
 
  ArrayAttrs.each do |attr, method|
    define_method method do |val|
      clone { |i| i.send(attr) << val }
    end
  end
 
  ObjectAttrs.each do |attr|
    define_method attr do |val|
      clone { |i| i.send("#{attr}=", val) }
    end
  end
 
  protected
  attr_writer *ArrayAttrs.keys
  attr_writer *ObjectAttrs
 
  def clone
    Inquisitio.new do |i|
      (ObjectAttrs + ArrayAttrs.keys).each do |attr|
        i.instance_variable_set("@#{attr}", instance_variable_get("@#{attr}"))
      end
      yield i
    end
  end
 
end
 
thing = Inquisitio.where(x: true).limit(5).order("foobar desc")
thing = thing.where(y: false)
p thing