[Oberon] RE: PIC (was Re. Staapl)

Jorg Straube joerg.straube at iaeth.ch
Tue Jul 29 17:56:50 MEST 2008


Hi Chris
 
>OTOH I'm confused that he writes: ----------
>> Conditional statements have the form shown at the left
>> and explained in terms of conventional notation to
>> the right.
>> 
>> [cond -> StatSeq]               IF cond THEN Statseq END

I just browsed through Wirth's papers:
1) <http://www.inf.ethz.ch/personal/wirth/Articles/Miscellaneous/PICL.pdf>
2)
<http://www.inf.ethz.ch/personal/wirth/Articles/Miscellaneous/PICLcompiler.p
df>

The short syntax "[ Cond -> StatSeq ]" mentioned in 2) was
eventually replaced by the long syntax "IF Cond THEN StatSeq END".

But even in 1) you find small "left overs" of this syntax:
* In 1) chap 1 you'll find "symbol = + | - ... | ->". The syntactic
  token "->" is foreseen.
* In chapter 5, the "->" is used in "GuardedStat = Condition -> StatSeq"
  But GuardedStat is not used.

The two papers are not consistent and just not complete (yet!).
They seem to be in "draft" state.

br
Joerg



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