Re: [Emacs-diffs] emacs-25 504696d: Etags: yet another improvement in Ruby tags

[Dmitry Gutov]

On 02/03/2016 07:25 PM, Eli Zaretskii wrote:

> --- a/test/etags/ruby-src/test1.ru
> +++ b/test/etags/ruby-src/test1.ru
> @@ -24,10 +24,14 @@ module A
>       end
>       def X

Just noticed this. attr_X calls will not, as a rule, be inside a method 
definition (which is what 'def X' is).

If an attr_X call is inside a method definition, we're unlikely to be 
able to make much sense of it. Most likely, the arguments will be local 
variables, not Symbol literals. It's also likely that the target of this 
call in that kind of situation won't be the current class.

Anyway, the example shouldn't put attr_X calls inside a method 
definition, or it gives an impression that we handle this situation 
intentionally, or somehow differently from the usual case. Whereas we 
could as well skip those tags altogether (but we don't really have to, 
as long as we only generate non-qualified tags, and check that every 
argument is a Symbol literal, i.e. it starts with a colon).

>         attr_reader :foo
> -      attr_reader :read1, :read2; attr_writer :write1, :write2
> -      attr_writer :bar
> +      attr_reader :read1 , :read2; attr_writer :write1, :write2
> +      attr_writer :bar,
> +                  :baz,
> +                  :more
>         attr_accessor :tee
> -      alias_method :qux, :tee
> +      alias_method :qux, :tee, attr_accessor :bogus

This one is a bit weird as well:

- An alias_method call with three arguments will raise an ArgumentError.

- If it didn't, the 'attr_accessor :bogus' calls would raise a 
SyntaxError, due to evaluation rules. However, an attr_X call can be 
inside an expression, such as:

class C
  puts(attr_accessor :bogus)
end

This is not a typical case, we don't need to handle it, but it's odd to 
see a test case that implies that this example is invalid, and we 
somehow prohibit it. Hopefully, this observation will allow you to 
simplify some code.