From: Good Night Moon <no.email.here@...>
Date: 2007-07-23T05:30:02+09:00
Subject: Parsing bug with 'return not' (was, Syntax bug)

On Sun, 22 Jul 2007 03:50:01 -0400, Bil Kleb wrote:
>>   myrect.rb:8: syntax error, unexpected kNOT, expecting kEND
>>       return  not ((other.x1 < self.x0 or self.x1 < other.x0) and
> 
> You need to use the '!' operator instead of the 'not' "conjunction".
> It's a precedence thing -- the parser is seeing 'return not' -- see
> parse.y in the source.

Thanks, maybe I'll look. It's not just precedence though, or else 
'return' itself is part of it: 

  def ok
    return (not true)
  end

  def fails
    return not true
  end

And note that within an 'if', it works as you'd expect: 

  def with_parens_ok
    if (not true)
      puts "not true"
    end
  end

  def no_parens_ok
    if not true
      puts "not true"
    end
  end