From: Rick DeNatale <rick.denatale@...>
Date: 2006-09-10T01:16:56+09:00
Subject: Re: BEST alias_method Re: [CHALLENGE] better alias_method

On 9/8/06, ara.t.howard@noaa.gov <ara.t.howard@noaa.gov> wrote:

> the primary reason to use aliases is not to simply have another handle on
> names - but override or wrap a method for instance.

Here's a sketch which generalizes this a little and adds a module
method sort of like private, which syncronizes the next method to be
defined.

I'm not sure how you'd make synchronized work like private and make
all subsequent methods synchronized. The issue is figuring out when to
turn it off when the module definition is closed.

rick@bill:/public/rubyscripts$ cat syncwrapper.rb
class Module

        alias_method "__method_added__", :method_added
        def method_added(meth_name)
                if @synchronize_new_method
                        @synchronize_new_method = false
                        synchronize_method(meth_name)
                end
                __method_added__(meth_name)
        end

        def synchronize_method(meth_name)
                module_eval {
                        alias_method "__#{meth_name}__", "#{meth_name}"
                }
                module_eval <<-code
                    def #{meth_name}(*a, &b)
                       p "Synchronized"
                       __#{meth_name}__(*a, &b)
                    end
                   code
        end

        def synchronized(*meth_names)
                @synchronize_new_method = meth_names.empty?
                meth_names.each do |meth_name|
                        synchronize_method(meth_name)
                end
        end
end

class C

        def fee
                42
        end

        synchronized
        def fie
                43
        end

        def foe
                44
        end

        def fum
                45
        end

        synchronized :foe
end

p C.new.fee
p C.new.fie
p C.new.foe
p C.new.fum

rick@bill:/public/rubyscripts$ ruby syncwrapper.rb
42
"Synchronized"
43
"Synchronized"
44
45



-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/