[Oberon] Numerical CASE Statements in Project Oberon

[David Egan Evans]

It appears that since 2013 (2011?) Wirth had intended type extension use of CASE only as a type guard (similar to its use in Pascal with variant records). See the second version of the differences document for this.

What's curious is that though he added the type guard use of CASE in the Report this year, he didn't otherwise remove CASE from it as he indicated (differences document), and implemented in PO2013. Perhaps this was a concession on Wirth's part in the Report, or perhaps he hasn't made a final determination on CASE.

Either way, I doubt he'll extend CASE in PO2013. CASE is now like Pascal again, but without the requirement for a trap (and thus no need for ELSE. A trap is implementation dependent). I think it more likely that he'll remove CASE from the Report, other than its use as a type guard for RECORD extension. However, with Wirth you never know.
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