[Oberon] Question about assignment of INTEGER to REAL in Oberon-07

Chris Burrows chris at cfbsoftware.com
Mon Dec 9 18:41:44 CET 2019

The removal of the type inclusion feature is mentioned in the main Project
Oberon documentation amongst others.

The meaning of the word 'implicity' i.e. "in a way that is suggested but not
communicated directly", gives a clue why it might be considered to be a
'less than desirable' feature. I wouldn't go as far as to say that it was a
'bad' feature. It is certainly not an 'essential' feature.

Chris Burrows
CFB Software

> -----Original Message-----
> From: Oberon [mailto:oberon-bounces at lists.inf.ethz.ch] On Behalf Of
> rochus.keller at bluewin.ch
> Sent: Tuesday, 10 December 2019 1:43 AM
> To: oberon at lists.inf.ethz.ch
> Subject: [Oberon] Question about assignment of INTEGER to REAL in
> Oberon-07
> From your previous responses I already learned that I should always
> have a look at the Oberon 90 language report as well.
> From the Oberon-07 report I would conclude that the assignment of an
> INTEGER to a REAL variable is not allowed. It states "The type of the
> expression must be the same as that of the designator".
> Whereas the Oberon 90 report states "The type of the expression must
> be included by the type of the variable" which seems more natural to
> me.
> Can you confirm that my interpretation of the Oberon-07 report is
> right? Why is it bad to implicitly convert INTEGER (usually 32 bit)
> to REAL (usually 64 bit) in an assignment (i.e. why was type
> inclusion removed)?
> Best
> R.
> --
> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related
> systems https://lists.inf.ethz.ch/mailman/listinfo/oberon

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