Project

General

Profile

Actions

Bug #19257

closed

Data that defines a member called hash

Added by solnic (Peter Solnica) almost 2 years ago. Updated almost 2 years ago.

Status:
Feedback
Assignee:
-
Target version:
-
ruby -v:
ruby 3.2.0 (2022-12-25 revision a528908271) [x86_64-darwin22]
[ruby-core:111422]

Description

I believe this should raise an error given that Data#hash exists as a pre-defined core method and serves a very specific purpose:

data = Data.define(:hash)

obj = data.new(hash: "foo")

obj.hash
# => "foo"

An alternative would be to make obj[:hash] return the value of the member and obj.hash would return the hash of the object, but that could be confusing.

Updated by nobu (Nobuyoshi Nakada) almost 2 years ago

  • Status changed from Open to Feedback

Always you can override methods defined in super classes.

class C
end
obj = C.new
p obj.hash #=> an integer

class C
  def hash = "foo"
end
p obj.hash #=> "foo"

No #[] method is a significant difference from Struct.

Updated by ufuk (Ufuk Kayserilioglu) almost 2 years ago

While I understand the potential for confusion or a foot-gun, I also agree with @nobu (Nobuyoshi Nakada) that this is in spirit with how Ruby operates, where anything is overridable. Struct has been behaving in the exact same way for years:

irb(main):001:0> Foo = Struct.new(:hash)
=> Foo
irb(main):002:0> Foo.new(42).hash
=> 42
irb(main):003:0> Bar = Struct.new(:bar)
=> Bar
irb(main):004:0> Bar.new(42).hash
=> 4004416633903135689

Having said that, if the proposal was to add a warning for when users override some special methods, like hash or object_id or something, then I would be all for that. A warning for these situations is good enough to warn people who might be doing this by mistake, but is not as drastic as an error preventing them from doing it.

Actions

Also available in: Atom PDF

Like0
Like0Like0