From: sera@... (Francis Hwang)
Date: 2003-12-16T13:11:56+09:00
Subject: trying to override != or create a unary negation method

I'm trying to add Criteria-style query inference to Lafcadio, which so
far has involved making a class that overrides == . So far, so good.
Now I'd like to override != so that I can turn the block

  { |user| user.email != "test@test.com" }

into the sql

  select * from users where !(email = 'test@test.com')

The trusty Pickaxe sez you can't define != independently of ==, and
that once you've defined ==, any call to

  a != b 

is implicitly turned into

  !(a == b)

So I figure, fine, I can make my query condition objects flip
themselves when they're negated. Tried creating a unary negation
method:

  def !@
    # ...
  end

and just got a syntax error. Any ideas as to what I could try next?