From: Rick DeNatale <rick.denatale@...>
Date: 2007-07-26T01:51:34+09:00
Subject: Re: Parsing bug with 'return not' (was, Syntax bug)

On 7/22/07, Gregory Brown <gregory.t.brown@gmail.com> wrote:
> On 7/22/07, Good Night Moon <no.email.here@zombo.com> wrote:
> > 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:
>
> if binds differently than return.  It is precedence.

Except that return isn't an operator.  As far as I can tell, looking
at parse.y for ruby1.8.6 the parse tree for the original statement
which raised the question

return not true

should be:

command_call
  kRETURN      expr
                         kNOT   expr
                                        primary
                                           var_ref
                                              variable
                                                 kTRUE

There definitely looks to be something strange here.

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/