Mixins and variables

[Johannes Friestad]

Hi,
I'm new to Ruby, and trying to figure out how the inheritance/mixin works:
I can't figure out how to set an instance variable with a mixin method
from the object's initialize().

Example:
-----------------
module TestMod
def x
@x
end
def x=3D(arg)
@x=3Darg
end
end

class TestClass
include TestMod
def initialize
x=3D('alpha')
printf("x=3D%s\n", x)
end
end

irb(main)..>tmp=3DTestClass.new
x=3Dalpha # x is set inside constructor
=3D> #<TestClass:0x37d9520>
irb(main)..>tmp.x
=3D> nil # x is unset on the returned object

 

[James Edward Gray II]

Hi,
I'm new to Ruby, and trying to figure out how the inheritance/mixin
works:
I can't figure out how to set an instance variable with a mixin method
from the object's initialize().

I see you have your answer, so let me just make some general comments:

Example:
-----------------
module TestMod
def x
@x
end
def x=(arg)
@x=arg
end

You can replace the last six lines with:

attr_accessor :x

end

class TestClass
include TestMod
def initialize
x=('alpha')

self.x = 'alpha' # as discussed, or just @x = 'alpha'

printf("x=%s\n", x)

And we would usually write that as:

puts "x=#{x}"

end
end

Hope that gives you an idea or two.

James Edward Gray II