Feature #7349: Struct#inspect needs more meaningful output

• Status: Assigned
• Assignee: matz (Yukihiro Matsumoto)
• Target version: -

[postmodern (Hal Brodigan)]

When inheriting directly from Struct.new, Class#ancestors shows a meaningless anonymous Class:

class Point < Struct.new(:x, :y)

  def distance
    ((x ** 2) + (y ** 2)) ** 0.5
  end

end

Point.ancestors
# => [Point, #<Class:0x007fe204a1a228>, Struct, Enumerable, Object, Kernel, BasicObject]

Perhaps, the anonymous Class could list the Struct's fields?

#<Class:x, y>

[shyouhei (Shyouhei Urabe)]

Sounds nice to me. +1

[claytrump (Clay Trump)]

I like it too. Could even be:

 Point.ancestors
 # => [Point, Struct.new(:x, :y), Struct, Enumerable, Object, Kernel,

BasicObject]

--

[Eregon (Benoit Daloze)]

It might be worth pointing out that this should not happen if the Struct generated class is assigned to a constant (and so one level of inheritance is not unused):

Point = Struct.new(:x, :y) do
def distance
Math.hypot(x,y)
end
end

[mame (Yusuke Endoh)]

• Tracker changed from Bug to Feature

[mame (Yusuke Endoh)]

• Status changed from Open to Assigned
• Assignee set to matz (Yukihiro Matsumoto)

[mame (Yusuke Endoh)]

This is not a bug. This ticket has been moved to the feature tracker.

I'm not against this proposal, but I don't think that people normally check the singleton class to know Struct fields. You may want to use Struct.#members:

p Point.members #=> [:x, :y]

It is shorter than ancestors.

--
Yusuke Endoh [e-mail]

[naruse (Yui NARUSE)]

• Target version deleted (2.6)