From: itsme213 <itsme213@...>
Date: 2005-01-07T00:26:30+09:00
Subject: Re: Ruby design question: lazy construction of object graph containing forward references


"Florian Gross" <flgr@ccan.de> wrote in message
news:344v8dF44miunU2@individual.net...
> itsme213 wrote:
>
> > I want to build such structures lazily, but be lazy only when the
laziness
> > is needed i.e. not for :f0=>x, or [x, y, ...], or y.f1. And I would like
to
> > force resolution of (selected or all) unresolved references either:
> > a) at a time of my choosing (raising exceptions if needed), or
> > b) incrementally whenever a given reference becomes resolvable, or
> > c) when something is done with that reference i.e. some method invoked
on it
> > (line 6).
>
> I'm not sure if I'm overlooking something, but I'd use blocks for this.
> E.g.
>
> foo = LazyStruct.new
> bar = LazyStruct.new
> foo.bar { bar.foo }
> bar.foo = 5
>
> Pardon the poor example. Does this make sense?

It would, but I was not clear : changing the ordering of construction of the
objects and links is not an option. I could have other uses of bar.foo, or
foo.bar either before or after your code fragment.

Thanks, though!