[Oberon] Module aliases - what is the correct way to handle them

[Chris Burrows]

> -----Original Message-----
> From: Oberon [mailto:oberon-bounces at lists.inf.ethz.ch] On Behalf Of
> Paul Reed
> Sent: Sunday, 16 February 2020 10:38 PM
> To: ETH Oberon and related systems
> Subject: Re: [Oberon] Module aliases - what is the correct way to
> handle them
> 
> Hi Chris,
> 
> > I think that the language spec does have such a restriction. In one
> M0
> > is a module alias, in the other M0 is an actual module name. A
> single
> > identifier (i.e. M0) can't be used for two different purposes in
> the
> > same scope... the report says nothing about the order in which the
> > import list should be processed.
> > IMPORT Z := M0, M0 := M1 ... Should be treated identically to
> IMPORT
> > M0 := M1, Z := M0
> 
> Thanks, and (I'm sorry if this is boring for everyone else) now I'm
> beginning to see that Jorg and I are thinking one way and you and
> Andreas are perhaps thinking another, which has helped me understand
> where the complications have come in.
> 
> I don't have a problem with the above being switched around because I
> (and Jorg) see the aliases and the canonical module names as
> different things.  I think you and Andreas are allowing a module
> alias to appear on the right hand side of an alias definition, but I
> wouldn't.  What's right?
> 

No - I agree with you. I was just pointing out that if aliases were allowed
on the right hand side of an alias definition it could result in ambiguous
import lists.