[ruby-list:30171] Re: How do we treat local static variables?

にし＠おかやまです。

元メールの方はスマートに解決した様ですが，力押しでもなんとかなりまっせ的
解法ということで，delegate.rbからコードを拝借してこんな風にしてみました。

-- 
NISHI Takao    D add ninth Co.,Ltd.
  1-2-24 Toyonari, Okayama, 700-0942, Japan
  Phone:[phone]  Facsimile:[phone]         @@@@
  mailto:[e-mail]    http://www.Dadd9.com/         OO/
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require 'singleton'

class StaticBasePool<Hash
    include Singleton
end

class Static

    def initialize(obj)
	@pool=StaticBasePool.instance
	@tag=getCallerMethodName
	unless(@pool.has_key?(@tag))
	    @pool[@tag]=obj
	end

	@val=@pool[@tag]

        #
        # following code originate from delegate.rb 
        #
	preserved = ::Kernel.instance_methods
	preserved -= ["to_s","to_a","inspect","==","=~","==="]
	for t in self.type.ancestors
	    preserved |= t.instance_methods
	    preserved |= t.private_instance_methods
	    preserved |= t.protected_instance_methods
	    break if t == Static
	end
	for method in @val.methods
	    next if preserved.include? method
	    eval <<-EOS
	    def self.#{method}(*args, &block)
		begin
                    @pool[@tag]=@val.__send__(:#{method}, *args, &block)
                    return @pool[@tag]
		rescue Exception
                    $@.delete_if{|s| /^\\(eval\\):/ =~ s}
                    raise
                end
            end
            EOS
        end
    end

    private
    def getCallerMethodName
        tmp=caller[2].split(":in ",2)
        return tmp[0].split(":")[-1].to_s+":"+tmp[1]
    end
end
	

def foo
    s=Static.new(0)
    s+=1

    return s
end

def bar
    s=Static.new("")
    t=Static.new(0)
    
    s+="."
    t+=2

    return [s,t]
end

10.times{
    p foo
    p bar
}