Struct.new and symbol with question mark

Ruby
1

Why isn’t the Struct class smart enough to detect a question mark at the
end of a member name and create the appropriate #member= and #member?
methods?

Klass = Struct.new :foo, :bar?
=> Klass

x = Klass.new
=> #<struct Klass foo=nil, :bar?=nil>

x.foo
=> nil

x.bar?
NoMethodError: undefined method `bar?’ for #<struct Klass foo=nil,
:bar?=nil>
from (irb):5
from :0

I was expecting Klass to have the #foo, #foo=, #bar?, and #bar= methods.

2

On Nov 6, 2006, at 11:58 PM, Suraj K. wrote:

methods.
It doesn’t work because :bar? isn’t a valid symbol literal. The
follow does work:

#! /usr/bin/env ruby -w Baz = Struct.new(:foo, :'bar?') z = Baz.new(42, false) z # => # z.bar? # => false

Regards, Morton

3

Suraj K. wrote:

Why isn’t the Struct class smart enough to detect a question mark at the
end of a member name and create the appropriate #member= and #member?
methods?

It could have been made smart enough, but certain people decided that
sort of convenience was “incorrect programming”.

See ruby-core:5796 and following.

Regards,

Dan