[m-rev.] For review: State Variable Transformation

[Fergus Henderson]

On 07-May-2002, Ralph Becket <rafe at cs.mu.OZ.AU> wrote:
> Fergus Henderson, Monday,  6 May 2002:
> > > Index: doc/reference_manual.texi
> > ...
> > > +
> > > +(Use of DCG syntax to thread hidden variables is now deprecated; the
> > > +preferred mechanism is to use state variables instead.)
> > 
> > I object to this.  I do not think DCGs should be officially deprecated.
> 
> I wasn't suggesting that DCGs be deprecated in general, rather just for
> threading state.  Can you suggest better wording or do you also object
> to that line?

Saying that something is deprecated is the standardese way of implying
that it may be removed in a future version, and I don't want DCGs to be
removed, which is why I object to that wording.

If you want to make some parenthetical suggestions about programming style,
I don't object to that, so long as they are clearly labelled as such.

For example, maybe something along these lines:

	(Note that if there is only one entity being threaded
	through a computation, either DCG notation or state variable
	notation could be used.  As a matter of style, we recommend that
	state variable notation be used if the entity represents some kind
	of state, and DCG notation only be used for actual grammars.)

However, I'm not entirely happy with these words -- I don't think the
distinction here is very clear.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
The University of Melbourne         |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.
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