Search found 54 matches

by augustk
Tue May 10, 2016 8:36 am
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-03
Replies: 4
Views: 16887

Re: Oberon Report Update 2016-05-03

My conclusion is that the EBNF in the Appendix is correct. The wrong semicolon was originally removed in Section 11 and has not been restored yet - otherwise the example in Section 11 would be incorrect. Yes, you are correct. I never noticed the previous error with the extra semicolon in section 11...
by augustk
Mon May 09, 2016 8:48 pm
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-03
Replies: 4
Views: 16887

Re: Oberon Report Update 2016-05-03

As of 2016-05-08 the semicolon after the import list has also been dropped.
by augustk
Sun May 08, 2016 7:26 pm
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-03
Replies: 4
Views: 16887

Oberon Report Update 2016-05-03

1. The real number scale factor "D" is deleted in the grammar in the appendix. Now it's consistent with the syntax in section 3 where only "E" is valid. 2. There is no semicolon after a module identifier. (Currently the grammar in the appendix is not updated). https://www.inf.ethz.ch/personal/wirth/...
by augustk
Tue May 03, 2016 5:44 am
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-01
Replies: 33
Views: 110152

Re: Oberon Report Update 2016-05-01

What I mean is: Can a variable of type ARRAY n OF T or ARRAY OF T be assigned to a variable of type ARRAY OF T? No. But why can open array be the source of an assignment then? I can't see the reason for allowing open arrays to be the source of an assignment but not the target (of a variable paramet...
by augustk
Mon May 02, 2016 8:18 pm
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-01
Replies: 33
Views: 110152

Re: Oberon Report Update 2016-05-01

Can an open array be the target of an assignment? From the Report: "The type of the expression must be the same as that of the designator" and "Strings can be assigned to any array of characters..." What I mean is: Can a variable of type ARRAY n OF T or ARRAY OF T be assigned to a variable of type ...
by augustk
Mon May 02, 2016 2:21 pm
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-01
Replies: 33
Views: 110152

Re: Oberon Report Update 2016-05-01

In the latest revision "an open array may be assigned to an array of equal base type" but what about the other way around: Can an open array be the target of an assignment? After all, when a formal parameter is an open array a corresponding actual parameter can be an array of any length.
by augustk
Mon May 02, 2016 10:29 am
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-01
Replies: 33
Views: 110152

Re: Oberon Report Update 2016-05-01

Isn't REAL a predeclared type so that REAL = INTEGER is a redeclaration? It's a predefined type e.g. like ABS . It is not a reserved word like BEGIN . e.g. in earlier versions of Oberon-07 you could have written: PROCEDURE REAL(i: INTEGER); BEGIN END REAL; As far as I understand the above declarati...
by augustk
Mon May 02, 2016 10:22 am
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-01
Replies: 33
Views: 110152

Re: Oberon Report Update 2016-05-01

The restriction to only allow structured types was introduced in Oberon-07: TypeDeclaration = identdef "=" StrucType. StrucType = ArrayType | RecordType | PointerType | ProcedureType. type = qualident | StrucType. Ah, of course. It's evident from the grammar. My bad. Allowing only structured types ...
by augustk
Mon May 02, 2016 8:17 am
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-01
Replies: 33
Views: 110152

Re: Oberon Report Update 2016-05-01

As I understand it, the decision between "null-terminated if needed" and "always null-terminated" character arrays is a trade off between declaration interpretation complexity and algorithm complexity. Let's consider the declaration name: ARRAY 32 OF CHAR With the "null-terminated if needed" approac...
by augustk
Mon May 02, 2016 7:13 am
Forum: Oberon Language
Topic: Oberon Report Update 2016-05-01
Replies: 33
Views: 110152

Re: Oberon Report Update 2016-05-01

qualident can be a basic type. There is an example of this use in the FileDir module in Project Oberon 2013 If my memory serves me correctly, I have read somewhere a text by Niklaus Wirth where he says that the right hand side of a type declaration must be a structured type. My "default" understand...