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From: uebau08@iravcl.ira.uka.de
Newsgroups: comp.lang.modula2
Subject: Re: Re^2: Error in PD Modula-2 compiler? Or just in my brain?
Message-ID: <309@iravcl.ira.uka.de>
Date: 19 Jun 89 16:43:21 GMT
References: <340@actisb.UUCP> <1090@gmdzi.UUCP> <1231@infbs.UUCP> <1130@eiger.iis.UUCP>
Lines: 31
Organisation: Universitaet Karlsruhe, IRA, F.R. Germany

In article <1130@eiger.iis.UUCP>, heiser@iis.UUCP (Gernot Heiser) writes:
> In article <1231@infbs.UUCP> neitzel@infbs.UUCP (Martin Neitzel) writes:
>>kloppen@gmdzi.UUCP (Jelske Kloppenburg) writes:
>>   procedure [pim3, 10.2].  Especially, VAL conversions guarantee to
>>   preserve the value, which may involve changes in the representation.
>>   Type transfers, on the other hand, do not.
>>
> 
> Correct according to THE BOOK. However, N.W. sometimes changes his mind too. In
> particular about three years ago he decided that use of the (UNSAFE) type
> transfer functions should be discouraged. Furthermore being a system dependent
> thing, type coercions should really be designated as such by having to be
> imported from SYSTEM.
> 
> In addition he apparently also decided that the (SAFE) type casts as
> originally provided by the standard function VAL were unnecessary. So he ended
> up doing away with type transfer functions, assigning their former meaning to
> VAL and putting the latter into SYSTEM. That's the way it is implemented in all
> the (one pass) compilers that left ETH in the last few years.
> 
> Last I heard from the standardisation commitee is that they were undecided
> which of the two STANDARDS to follow (or even come up with a third
> alternative).
> -- 
> Gernot Heiser                   Phone:       +41 1/256 23 48
> Integrated Systems Laboratory   CSNET/ARPA:  heiser%iis.ethz.ch@relay.cs.net
> ETH Zuerich                     UUCP (new):  heiser@iis.uucp
> CH-8092 Zuerich, Switzerland    UUCP (old):  {uunet,mcvax,...}!iis!heiser