From: Chris Pine <nemo@...>
Date: 2003-04-09T07:45:28+09:00
Subject: Re: The "!" and "?" characters.

----- Original Message -----
From: "Daniel Carrera" <dcarrera@math.umd.edu>

This is cool.  But it'd be cooler if I could write 'def !' and '5.!'.
But 'def !' causes a parse error.

Now my question:
Does anyone know why 'def !' causes a parse error?
----------------------------

Because it's interpreting `!' as `not', I think.  You can usually get around
these problems by sending symbols, but `:!' gives a parse error.  You can
usually get around *those* problems by interning a string:

  irb(main):001:0> class Integer
  irb(main):002:1>   define_method ('!'.intern) {self *
(self-1).send('!'.intern)}
  irb(main):003:1> end
  => #<Proc:0x400d3234@(irb):2>
  irb(main):004:0> 5.send ('!'.intern)
  Segmentation fault

Oops.

Hmmm...

Chris