My bookmarks from Diigo 01/07/2009

• Eavesdropping on Expressions - Moonbase

  tags: ruby, tab

  • class Object
    def tap
    yield self
    self
    end
    end
  • xs = blah.sort.grep( /foo/ )
    p xs
    
    # do whatever we had been doing with the original expression
    xs.map { |x| x.blah }

  • With Object#tap, this becomes much easier—you can just slip it in without radically modifying the code:

    
    
    
    

    blah.sort.grep( /foo/ ).tap { |xs| p xs }.map { |x| x.blah }

  • The traditional way:

    
    
    
    

    def blah
      sum = @things.map { |x|
        x.length
      }.inject( 0 ) { |a, b|
        a + b
      }
      p sum
      sum
    end

  • The Object#tap way:

    
    
    
    

    def blah
      @things.map { |x|
        x.length
      }.inject( 0 ) { |a, b|
        a + b
      }.tap { |sum| p sum }
    end

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