From: Morton Goldberg <m_goldberg@...>
Date: 2006-10-26T04:25:01+09:00
Subject: Pass block instead of here document?

I have a situation where I want to send many messages, one after the  
other, to single object. Instead of writing, say,

    foo.eat burger, fries
    foo.drink beer
    foo.be_merry

I want to be able to write something like:

   foo.perform { eat burger, fries; drink beer; be_merry }

I'm not much at meta-programming. The best I've been able to come up  
with so far is:

<code>
#! /usr/bin/env ruby -w

class Foo
    def report
       defined_here = (methods - Object.methods).join(", ")
       puts "#{self.class.name} defines: " + defined_here
    end
    def say(text)
       puts %[#{inspect} says "#{text}"]
    end
    def eat(*food)
       food = food.join(" and ")
       say "Downing #{food}. Yum, yum, yum!"
    end
    def drink(beverage)
       say "Chug, chug, chug"
    end
    def be_merry
       say "What, me worry?"
    end
end

module Kernel
    def tell(obj, to_do)
       obj.instance_eval(to_do)
    end
end

tell Foo.new, <<TO_DO
    report
    eat 'burger', 'fries'
    drink 'beer'
    be_merry
TO_DO
</code>

Although this works, it offends my sense of programming esthetics.  
I'd rather pass in a block. Is there a way to do that? Something like:

<pseud-code>
module Kernel
    def tell(obj, &to_do)
       # what goes here?
    end
end

tell Foo.new do
    report
    eat 'burger', 'fries'
    drink 'beer'
    be_merry
end
</pseud-code>

Instead of a Kernel#tell method, a Foo#perform method would be OK:

<pseud-code>
Foo.new.perform { report; eat 'burger', 'fries'; drink 'beer';  
be_merry }
</pseud-code>

Regards, Morton