Re.[Oberon] Native 24.08.2002: Compiler Bug

[eas-lab at absamail.co.za]

  Stefan Salewski wrote:
> I think there is something wrong with the DIV statement.

Yes, it's the same with n-o alpha 2001.   Also using constants:

10  DIV 3 = 3
- 10  DIV 3 = - 3   // DIV has precendence over "-"
-(-10  DIV 3) = 3

(-10)  DIV 3 = - 4 // truncates toward minus-infinity ?!
-((-10)  DIV 3) = 4

Besides this, looking into DIV raised other issues for me.

Desktops.OpenDoc  Oberon.Report.Text ~   shows:
They are related by the following formulas defined for any x and
 positive divisors y:
x = (x DIV y) * y + (x MOD y)
0 <= (x MOD y) < y

Examples:
x	y	x DIV y	x MOD y
5	3   	1         	2
-5	  3  	-2        	1
======
I would expect DIV to 'truncate towards zero'. Not towards minus infinity ?


And when I try to analyse the 'rules' further I'm confused:

* From Oberon.Report.Text
operator DIV: first operand = integer ; second operand = integer
   result type = smallest integer type including both operands

So here Oberon.Report.Text DIV defines the 2 operands 'symetically',
but elsewhere "positive divisors y"  (x may not be positive).  

* Then let's see the definition/syntax of "integer":-
integer 	= digit {digit} | digit {hexDigit} "H".
real 	= digit {digit} "." {digit} [ScaleFactor].
ScaleFactor 	= ("E" | "D") ["+" | "-"] digit {digit}.

It seems to me, that from the above "-10" would fail the syntax of an
integer ? !   Where is my reasoning wrong ? 
Apparently "integer" is not type INTEGER ?


So my queries are:
1. is -10 a n-o 'integer' ?
2. are the valid two operands of DIV of the same type ?
3. are these claims of mine of inconsistency in Oberon.Report.Text valid ?

-- Chris Glur.