From: Lennon Day-Reynolds <lennon@...>
Date: 2003-03-15T12:29:50+09:00
Subject: Re: Overloaded operator interprets block as hash

Every variation I've tried of passing a block as a parameter to an 
operator fails with a syntax error, so at least on 1.6.8/Win32, there 
doesn't appear to be any syntactic support for what you're trying to do. 
Of course, you could just have the operator accept a Proc instance, 
rather than a bare block, as a parameter, at the cost of five extra 
characters for each call.


Lennon

Phil Tomson wrote:

>I'm trying to define an operator that takes a block, like:
>
>a << {puts "Action!"}
>
>but the part in '{}' gets interpreted as a hash.  Here's the sample code:
>class Foo
>   def initialize(&proc)
>     @closure = proc
>   end
>
>   def assign(newVal = Proc.new)
>     @closure = newVal
>   end
>
>   def <<(newVal = Proc.new)
>     @closure = newVal
>   end
>   def callit
>     @closure.call
>   end
>end
>
>f= Foo.new { puts "Action!" }
>f.callit #=> "Action!"
>f.assign { puts "New Action!" }
>f.callit #=> "New Action!"
>f<< { puts "Latest Action!" }
>
>SyntaxError: compile error
>(irb):26: parse error
>f << { puts "Latest Action!" }
>                            ^
>        from (irb):26
>
>.... it seems as though the block being passed to '<<' is getting 
>interpreted as a hash while it isn't for the 'assign' method.  Is there 
>anyway around this?
>
>
>Phil
>
>  
>