Current best practices for resource acquizition and cleanup?

General Usage
1

I took me by surprise that

    with DBInterface.execute(db, sql) as q
        # do stuff with q
    end

does not deterministically finalize (destruct) q. After digging deeper (e.g. https://github.com/JuliaLang/julia/issues/7721 ) I found out, that up to mid-2019 it is a known problem in the Julia language specification.

There are exactly two walkarounds of this problem. One is to define

DBInterface.execute(f::Function, args...) = begin
  conn = db_connect(args...)
  try
    f(conn)
  finally
    finalize(conn)
  end
end

and use it like this:

    DBInterface.execute(db, sql) do q
        # do stuff with q
    end

and other, low-level solution is

    q = DBInterface.execute(db, sql)
    try
        # do stuff with q
    finally
        finalize(q)
    end

The latter solution is a little tricky, because a slight variation will not work:

    try q = DBInterface.execute(db, sql)
        # do stuff with q
    finally
        finalize(q) # Error: q is out of scope here!
    end

Stefan Karpinski was fond of a special suffix “!” notation:

    with DBInterface.execute(db, sql)! as q
        # do stuff with q
    end

…but that thread is dead for over 6 months.

Did I miss any development on this topic?