Question

Im working with a class, containing large instance arrays.

Whenever I initialize a class like this, e.g. i = Image.new, I get a lot of junk output from my arrays (@r, @g, @b – ~300k values each).

 class Image

   def initialize(width=640, height=480, brightness=64)
     @width, @height, @brightness = width, height, brightness
     self.load('usart.dat')
   end

   def load(file='usart.dat')
     self.reset
     f = IO.read(file, @height * @width * 2, 0)

     # Parsing the datafile, saving data in @r, @g, @b, @gray etc

     end

     return self
   end

   # ... More methods
 end

Question is, how can I either silence the output (all results are saved to a file, never viewed in the console) or make an initializer NOT inspect self. I want to return self, since I want to stack methods, e.g. image.load('file').binary.grayscale.save(:bin).

Answer 1

The output you are seeing is the result of your object’s to_s (or inspect). You can define/overwrite to_s (or inspect) for your classes to produce less output. E.g.

irb(main):001:0> class Foo
irb(main):002:1>   def initialize
irb(main):003:2>     @a = @b = @c = @d = 42
irb(main):004:2>   end
irb(main):005:1>
irb(main):006:1*   def to_s
irb(main):007:2>     'a Foo object'
irb(main):008:2>   end
irb(main):009:1> end
=> nil
irb(main):010:0> h = Foo.new
=> a Foo object
irb(main):011:0>

Regarding to_s/inspect: irb calls inspect which normally just calls to_s (see ruby-doc). So, defining to_s should normally work. However, if there is an inspect not calling to_s in the class (or its ancestors), this inspect has to be overwritten.