[Oberon] Assumed issue in the Lola-2 compiler

rochus.keller at bluewin.ch rochus.keller at bluewin.ch
Tue Apr 16 13:38:35 CEST 2019

@  Chris Burrows:

Thanks for the clarifications.

>> I incorrectly restated this in my previous post as: -1 DIV 16
This is equal to "(-1) DIV 16" since the minus prefix associates with the one, not the whole expression, isn't it?

>>  Section 7.1 .. in the document "Programming in Oberon (a Tutorial)"
We can only rely on the language report (or on the ISO standard in case of C/C++) as a autoritative reference, not on secondary literature or letters. ISO usually publishes clarifications and corrections between revisions and includes them in the official next revision of the standard. If therefore the Oberon "standard" were not complete or ambiguous, I would expect the next revision to address this.

Even with your clarifications I still consider it undecidable from the Oberon report whether "(-1) DIV 16" is zero or -1. There are good arguments (at least from my point of view) for both interpretations. But as already mentioned I've found a work around re-using regular features of the C++ compiler which gives me the same result in my C++ version like the Lola-2 compiler written in Oberon, which is my primary goal .


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