[ruby-talk:16971] Re: finalizers, destructors and whatnot

Fritz Heinrichmeyer <[e-mail]> writes:

[... regarding behavior of finalizers under reference counting and GC ...]

    Dave> I think that may have been the case.

    Dave> However, often the situation doesn't really arise in Ruby,
    Dave> as blocks are used for these kind of purposes. I've
    Dave> personally switched over to a style where 99% of resource
    Dave> management is done using blocks, and it really does make
    Dave> life simpler:

    Dave> DB.connect(name, pw) do |db|
    Dave>     # .. do lots of database stuff
    Dave> end

In fact, support for block centric resource management was explicitly
added to the (otherwise Perl-like) Ruby DBI interface.  

  DBI.connect("DBI:Pg:testdatabase") do |db|
    db.transaction do
      db.prepare ("UPDATE ...") do |st|
        st.execute(...)
      end      # st.finish automatically called

      db.execute("SELECT ...") do |st|
        st.each { |row|
          # Process Row
        }
      end      # st.finnish automatically called
    end        # db.commit automatically called
  end          # db.disconnect automatically called

If you wish, the Perl-like interface where values are explicitly
returned and managed is still available.  e.g.

  db = DBI.connect("DBI:Pg:testdatabase")
  ...
  db.disconnect

-- 
-- Jim Weirich