[m-dev.] treating `list__append' as `list:append'

[Fergus Henderson]

Peter Schachte, you wrote:
> 
> > Add code to treat `__' as an alternative syntax for module qualification.
> > The code is currently commented out, because we don't yet support
> > module qualification of data constructors.  It should be re-enabled
> > as soon as we do.
> 
> I hope this is a "feature" that will be removed after a release or
> two.  In the long run it really doesn't seem like a very nice
> linguistic feature, though I can see that breaking all users' calls to
> library predicates could be considered antisocial.

I agree it should eventually be removed, although I think we should
probably leave it in for more than one or two release.

> > Index: prog_io.m
> > +		string__sub_string_search(Name, "__", LeftLength),
> > +		LeftLength > 0
> 
> What if LeftLength = 0 (eg, "__foo")?  I would expect this to be
> treated as a variable, but this code, when uncommented, will return
> ok(unqualified(Name)).  Is this correct?

Yes, it is correct.

>If Name couldn't be of the form "__foo", perhaps you could omit the test?

If you write

	__foo

then that will be treated as a variable.
If you write

	'__foo'

then that will be treated as an (unqualified) functor.

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