From: Markus <markus@...>
Date: 2004-10-08T05:18:59+09:00
Subject: Bug in free-form operator patch

Shoot.

It doesn't correctly distinguish multiple user-defined operators on one
class.  I know what the problem is, and tonight I'll try to figure out
how to fix it.

-- Markus


On Thu, 2004-10-07 at 12:18, Markus wrote:
>         !!!   ->   <-   --   +++   -=-   */*   !!   ~~~   <=..<   ....
> 
> 
>       * Have you ever wanted to define your own operators in ruby?
> 
>       * Have you ever wanted to play around with experimental hash or
>         range semantics, but wanted a concise syntax for the
>         constructors?  
> 
>       * Are you crazy enough to install a compiler patch from someone
>         WHO OPENLY ADMITS TO NOT KNOW C?  (for those of you that need
>         everything quantified, that's a metric craziness index of about
>         0.6 Why)
> 
> If you answered yes to all of the above, have I got a patch for you.
> 
> ----------------------------------------------------------------
> 
> As mentioned previously, I've been working on a patch that would let you
> write things like:
>         
>         class Pair
>             attr_accessor :l,:r
>             def initialize(l,r)
>                 @l,@r = l,r
>                 end
>             end
>         
>         class Object
>             def -->(other)
>                Pair.new(self,other)
>                end
>             end
>         
>         print 1-->5,"\n"
>         
> This is the pre-alpha release of that patch.   Basically, any sequence
> of "operator characters" that isn't otherwise used is now user
> definable, though you are warned to use spaces where this would be
> ambiguous (e.g. x+=-1). 
> 
>      In this version, the operators are always binary, non-associative,
> and mid-precedence.  I can see how to let the users set the precedence,
> but can not figure out what "scope" the precedence declarations should
> have.  I can NOT see how it could depend on the class of the recipient,
> which would be in some ways idea and in others hideous.
> 
>      Several of you have expressed interest in this; let me know if you
> try it out & what you think.  Bug reports are especially welcome.
> 
>       -- Markus
> 
> ----------------------------------------------------------------
> 
>      Normally try to preface code I post with some sort of warning about
> the quality/soundness of the code I'm posting.  In this case, though, my
> C skills aren't up to rating my code here.  To me, it is much easier to
> read (albeit in theory microscopically slower) than the way C is usually
> written.  Native speakers of C will doubtlessly be scandalized by my
> accent.
> 
>      So the best I can do is say, 1) it works on my machine, 2) I
> haven't been able to measure any performance impact, 3) it doesn't seem
> to break anything that I know of, though it does generate some warnings
> (by design) on existing scripts that run operators together (e.g.
> x+=-1).
> 
>      I am NOT using this in a production environment, nor would I
> recommend any else do so.  But it's fun to play with. 
>