From: Eric Hodel <drbrain@...7.net>
Date: 2005-10-28T13:37:57+09:00
Subject: Re: Expression Evaluation Problem

On Oct 27, 2005, at 8:27 PM, Shannon Fang wrote:

> Hi,
>
> I have a program which runs ok for a very long time, today I try to  
> modify it some strange error pops up (before I modify):
>
> c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in  
> `require__': ./dbload.rb:110: void value expression (SyntaxError)
>    return (@acc.class == Hash) and (@auth.class == Hash) and  
> (@cat.class == Hash)
>                                                             ^  from  
> c:/ruby/lib
> /ruby/site_ruby/1.8/rubygems/custom_require.rb:18:in `require'
>        from F:/work/svn/dproc/dproc.rb:5
>
> The problematic source codes are as follow:
>
> dbload:
>  def loaded?
>    return (@acc.class == Hash) and (@auth.class == Hash) and  
> (@cat.class == Hash)
>  end
>
> Now I add a () in the loaded? function make it like:
>
>  return ((@acc.class == Hash) and (@auth.class == Hash) and  
> (@cat.class == Hash))
>
> The error disappeared!
>
> My question is, which operator has higher priority? return or and?

return is higher.

> I have used this code for a long time, but never had this problem  
> before... Any change in v1.8 probably?

No.

$ cat x.rb
def which?
   return 'return is higher' and 'and is higher'
end
puts which?
$ ruby168 -v x.rb
ruby 1.6.8 (2002-12-24) [powerpc-darwin8.2.0]
x.rb:2: void value expression
$ ruby182-orig -v x.rb
ruby 1.8.2 (2004-12-25) [powerpc-darwin8.0]
x.rb:2: void value expression

Maybe you had:

$ cat y.rb
def which?
   return 'return is higher' && '&& is higher'
end
puts which?
$ ruby -v y.rb
ruby 1.8.3 (2005-09-21) [powerpc-darwin8.2.0]
&& is higher


-- 
Eric Hodel - drbrain@segment7.net - http://segment7.net
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