## Bug #11878

Updated by nobu (Nobuyoshi Nakada) over 3 years ago

Including module `B` to class/module `A` gives the following results (as expected):

~~~ruby ~~~

module A; end

module B; end

A.include B

A < B # => true

B < A # => false

A <=> B # => -1

~~~

And prepending module `C` to `A` gives the following results:

~~~ruby ~~~

module C; end

A.prepend C

A < C # => true

C < A # => nil

A <=> C # => -1

~~~

It looks like including and prepending almost do not make difference with respect to module comparison, i.e., `A < B` and `A < C` are the same, and `A <=> B` and `A <=> C` are the same. However, then, the difference between `B < A` and `C < A` stands out unexplained. I suppose this is a bug. If `C < A` were to return `false`, then it would be at least consistent.

However, if that was what was intended, then at least to me, it is strange. In that case, I would like to make this a feature request. I would rather expect:

~~~ruby ~~~

A < C # => false

C < A # => true

A <=> C # => 1

~~~

~~~ruby ~~~

module A; end

module B; end

A.include B

A < B # => true

B < A # => false

A <=> B # => -1

~~~

And prepending module `C` to `A` gives the following results:

~~~ruby ~~~

module C; end

A.prepend C

A < C # => true

C < A # => nil

A <=> C # => -1

~~~

It looks like including and prepending almost do not make difference with respect to module comparison, i.e., `A < B` and `A < C` are the same, and `A <=> B` and `A <=> C` are the same. However, then, the difference between `B < A` and `C < A` stands out unexplained. I suppose this is a bug. If `C < A` were to return `false`, then it would be at least consistent.

However, if that was what was intended, then at least to me, it is strange. In that case, I would like to make this a feature request. I would rather expect:

~~~ruby ~~~

A < C # => false

C < A # => true

A <=> C # => 1

~~~