Module: RMTools::SmarterSetOps

Included in:
Array, Set
Defined in:
lib/rmtools/enumerable/set_ops.rb

Overview

Builtin methods overwrite. Why should we do zillions of cycles just for ensure ‘A | [] = A - [] = A or A & [] = []` ? Though #- and #& should be improved within C-extension to break loop when no items have had lost in self (Or not? Don’t remember what I had on my mind while I’ve being writing this)

Class Method Summary collapse

Class Method Details

.included(acceptor) ⇒ Object 



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# File 'lib/rmtools/enumerable/set_ops.rb', line 11

def self.included(acceptor)
  acceptor.class_eval {
    alias :union :|
    alias :coallition :+
    alias :subtraction :-
    alias :intersection :&
    # :& won't work this way if :intersection will be protected
    protected :union, :coallition, :subtraction
    
    def |(ary) 
      return ary.uniq if empty?
      return uniq if ary.respond_to? :empty? and ary.empty?
      
      union ary
    end
    
    def +(ary) 
      if empty?
        return [] if ary.respond_to? :empty? and ary.empty?
        ary.dup
      end
      return dup if ary.respond_to? :empty? and ary.empty?
      
      coallition ary
    end
    
    def -(ary) 
      return [] if empty?
      return dup if ary.respond_to? :empty? and ary.empty?
      
      subtraction ary
    end
    
    def &(ary) 
      return [] if empty? or (ary.respond_to? :empty? and ary.empty?)
      return ary.intersection self if size < ary.size
      
      intersection ary
    end
    
    def ^(ary)
      return [dup, ary.dup] if empty? or (ary.respond_to? :empty? and ary.empty?)
      return [[], []] if self == ary
      
      common = intersection ary
      [self - common, ary - common]
    end
    
    alias :diff :^
    
    def intersects?(ary)
      (self & ary).any?
    end
    alias :x? :intersects?
    
    def =~(ary)
      (self - ary).empty?
    end
    alias :is_subset_of? :=~
  }
  super
end