Feature #12046
closedAllow attr_reader :foo? to define instance method foo? for accessing @foo
Description
Now we should write an accessor method of a boolean instance variable like
def foo?
@foo
end
But I want to write it by using attr_reader like:
attr_reader :foo?
Updated by nobu (Nobuyoshi Nakada) almost 9 years ago
- Is duplicate of Feature #10720: A proposal for something like: attr_reader :foo? - with the trailing '?' question mark added
Updated by shevegen (Robert A. Heiler) over 8 years ago
Yay! Sometimes things just take a while. :)
Updated by matz (Yukihiro Matsumoto) over 8 years ago
- Status changed from Open to Rejected
as a rule, attr_reader x
creates an instance variable @x
, but we cannot have @x?
.
that's the reason, we reject attr_reader :foo?
. If you have any concrete use-case for
the new (more complex) behavior, please tell me.
Matz.
Updated by svoop (Sven Schwyn) about 8 years ago
If you have any concrete use-case for the new (more complex) behavior, please tell me.
This feature request has been rejected more than once, so I'm most likely doing this in vain. But the obvious use-case would be better readability. Right now, the way to do it is:
class Foobar
attr_accessor :color
attr_writer :transparent
def transparent?
@transparent
end
end
Even though the transparent reader is trivial, it has to be explicitly added and thus is not part of the list of other trivial accessors such as color.
If tailing question marks are ignored when trivial writers are created, the code looks as follows:
class Foobar
attr_accessor :color, :transparent?
end
The writer remains "transparent=", but it could reject any non-boolean values. The reader would be "transparent" with an alias "transparent?"
It's just a little magic to remove crust. And it wouldn't break any existing code because accessors and writers with tailing question marks raise "invalid attribute name" as of now.
Updated by mame (Yusuke Endoh) over 5 years ago
- Related to Feature #11167: Allow an attr_ variant for query-methods that end with a question mark '?' character, such as: def foo? returning @foo added
Updated by mame (Yusuke Endoh) over 5 years ago
- Related to Feature #5781: Query attributes (attribute methods ending in `?` mark) added
Updated by mrkn (Kenta Murata) about 5 years ago
- Related to Feature #15991: Allow questionmarks in variable names added
Updated by byroot (Jean Boussier) over 1 year ago
- Related to Feature #19708: Support `attr_reader :foo?` added