Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!bunyip.cc.uq.oz.au!brolga!uqcspe!cs.uq.oz.au!warwick
From: warwick@cs.uq.oz.au (Warwick Allison)
Newsgroups: comp.lang.modula2
Subject: Re: Missing from Modula-2
Message-ID: <2016@uqcspe.cs.uq.oz.au>
Date: 19 Jun 91 03:13:47 GMT
References: <IWM.91Jun18101949@swan.doc.ic.ac.uk>
Sender: news@cs.uq.oz.au
Reply-To: warwick@cs.uq.oz.au
Distribution: comp
Lines: 35

>Why, if the function f returns a pointer can I not write:
>
>       f(x)^.field := ...

I've always wondered this too.  All I can guess is that it make the parser
simpler not to allow both:

	Statement ::= Designator "(" ActualParameters ")"

   and

	Designator ::= Designator "(" ActualParameters ")"

 where
	Designator ::= Designator "^"
	Designator ::= Designator "[" ExprList "]"
	Designator ::= Designator "." Field
	Designator ::= QualifiedIdentifier

That doesn't look LALR(1), but I'm not sure.

Then again, M2 allows the syntax

	QualifiedIdentifier ::= Identifier { "." QualifiedIdentifier }

to screw up Designators (The semantic class of Identifier - ModuleName or Variable
is needed).


Warwick.
--
  _-_|\       warwick@cs.uq.oz.au
 /     *  <-- Computer Science Department,
 \_.-._/      University of Queensland,
      v       Brisbane, AUSTRALIA.