Will my "in?" monkey patch cause issues?

Question

So a fairly common pattern I've run up against is something like this:

[:offer, :message].include? message.message_type

The inversion of wording there messes me up. So I wrote this little monkey patch for Symbol in specific.

def in? *scope
  scope.include? self
end

So now I can do the previous this way:

message.message_type.in? :offer, :message

This works fine and I'm happy with it, but occasionally I need similar functionality for other objects. Model objects in Rails apps being the most common case but strings occasionally, etc.

What kind of issues would I run into if I monkey patched this directly into Object?

I looked but never found anything like this. Could you link the documentation? — Drew, Sep 09 '13 at 20:10
Patching `Object` or `Symbol` seems like you're asking for trouble, especially with such a short name. — tadman, Sep 09 '13 at 20:11
http://api.rubyonrails.org/classes/Object.html#method-i-in-3F — Sergio Tulentsev, Sep 09 '13 at 20:11
It was one of my first questions on this site: http://stackoverflow.com/questions/8133397/is-there-an-inverse-member-method-in-ruby — Sergio Tulentsev, Sep 09 '13 at 20:17
Interestingly enough, my implementation has been deprecated. I'd be curious to know why. — Drew, Sep 09 '13 at 20:17

score 2 · Answer 1 · answered Sep 09 '13 at 20:15

2

Rails (ActiveSupport) already patches Object with this method. Here is the documentation: http://api.rubyonrails.org/classes/Object.html#method-i-in-3F.

Returns true if this object is included in the argument. Argument must be any object which responds to #include?. Usage:

characters = ["Konata", "Kagami", "Tsukasa"]
"Konata".in?(characters) # => true

This will throw an ArgumentError if the argument doesn’t respond to #include?.

answered Sep 09 '13 at 20:15

Sergio Tulentsev

226,338
43
373
367

I approve of the Lucky Star reference incidentally. – Drew Sep 09 '13 at 20:17

Will my "in?" monkey patch cause issues?

1 Answers1