Why does it fail? def Module1::Module2.hello

ruby-talk
1

Hi, the following code fails:

module Module1
  module Module2
  end
end

def Module1::Module2.hello
  puts "HELLO"
end

syntax error, unexpected keyword_end, expecting $end

But I can do:

def Module1.hello
  puts "HELLO"
end

why does the former fail? Any trink?

Thanks a lot.

···

--
Iñaki Baz Castillo
<ibc@aliax.net>

2

I know one way to define module method

module Module1::Module2
  def self.hello
    puts 'HELLO'
  end
end

···

On Fri, Aug 3, 2012 at 11:13 PM, Iñaki Baz Castillo <ibc@aliax.net> wrote:

Hi, the following code fails:

module Module1
  module Module2
  end
end

def Module1::Module2.hello
  puts "HELLO"
end

syntax error, unexpected keyword_end, expecting $end

But I can do:

def Module1.hello
  puts "HELLO"
end

why does the former fail? Any trink?

Thanks a lot.

--
Iñaki Baz Castillo
<ibc@aliax.net>

--

William Herry

WilliamHerryChina@Gmail.com

3

Sure, but what I ask is why this works:

  def Module1.hello ; end

end this fails:

  def Module1::Module2.hello ; end

···

2012/8/4 William Herry <william.herry.china@gmail.com>:

I know one way to define module method

module Module1::Module2
  def self.hello
    puts 'HELLO'
  end
end

--
Iñaki Baz Castillo
<ibc@aliax.net>

4

Because it's how it defined in ruby syntax: def class; dot or color; method name
You can't use nesting in it. So it's limited on a lexer level.

···

On Aug 4, 2012, at 9:07 PM, Iñaki Baz Castillo wrote:

2012/8/4 William Herry <william.herry.china@gmail.com>:

I know one way to define module method

module Module1::Module2
def self.hello
   puts 'HELLO'
end
end

Sure, but what I ask is why this works:

def Module1.hello ; end

end this fails:

def Module1::Module2.hello ; end

--
Iñaki Baz Castillo
<ibc@aliax.net>

5

As Sigurd has pointed out, it's a syntax precedence thing. You can do
this however:

def (Module1::Module2).hello
  puts "HELLO"
end

Regards,
Sean

···

On Sat, Aug 4, 2012 at 7:07 PM, Iñaki Baz Castillo <ibc@aliax.net> wrote:

2012/8/4 William Herry <william.herry.china@gmail.com>:

I know one way to define module method

module Module1::Module2
  def self.hello
    puts 'HELLO'
  end
end

Sure, but what I ask is why this works:

  def Module1.hello ; end

end this fails:

  def Module1::Module2.hello ; end

--
Iñaki Baz Castillo
<ibc@aliax.net>

6

Thanks for the clarification.

···

2012/8/4 Sigurd <cu9ypd@gmail.com>:

Because it's how it defined in ruby syntax: def class; dot or color; method name
You can't use nesting in it. So it's limited on a lexer level.

--
Iñaki Baz Castillo
<ibc@aliax.net>

7

Great! thanks a lot.

···

2012/8/4 Sean O'Halpin <sean.ohalpin@gmail.com>:

As Sigurd has pointed out, it's a syntax precedence thing. You can do
this however:

def (Module1::Module2).hello
  puts "HELLO"
end

--
Iñaki Baz Castillo
<ibc@aliax.net>