From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2003-03-15T15:44:07+09:00
Subject: Re: Overloaded operator interprets block as hash (bug?)

In article <3E729E3F.7020007@day-reynolds.com>,
Lennon Day-Reynolds  <lennon@day-reynolds.com> wrote:
>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

True, but...
1) I'm sort of creating a domain specific language from Ruby (an HDL) and 
I'm trying to hide that sort of thing from the user.
2) I'm wondering if this is some sort of bug? 

Phil


>
>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
>>
>>  
>>
>
>