Re: [fpc-devel] TShiftState as enum

2005-02-20 Thread DrDiettrich 
Alexey Barkovoy wrote:

 Delphi dowsn't allow sets with ordinal values larger than 255 too:

That's incorrect.

 Borland Delphi  Version 13.0  Copyright (c) 1983,99 Inprise Corporation
 1.pas(2) Error: Sets may have at most 256 elements

Sets are restricted to a maximum of 256 members, but the ordinal values
of the members can be higher.

DoDi


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Re: [fpc-devel] TShiftState as enum

2005-02-20 Thread Alexey Barkovoy 
Delphi dowsn't allow sets with ordinal values larger than 255 too:
That's incorrect.
.
Sets are restricted to a maximum of 256 members, but the ordinal values
of the members can be higher.
As I've already posted: sample code below not compile in any Delphi version. You 
can try it yourself.

type aenum=510..517;
aset = set of aenum;
begin
 Writeln(sizeof(aset));
end.
Delphi 2005 emits:
Borland Delphi for Win32 compiler version 17.0
Copyright (c) 1983,2004 Borland Software Corporation
1.pas(2) Error: E2028 Sets may have at most 256 elements
1.pas(7) 

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Re: [fpc-devel] TShiftState as enum

2005-02-17 Thread Mattias Gaertner 
On Thu, 17 Feb 2005 08:58:01 +0100 (CET)
[EMAIL PROTECTED] (Marco van de Voort) wrote:

   TShiftState is defined as TShiftState = set of (...);
   
   How can I iterate through the enums? If not, can we split and add
   an enum:
   
   TShiftStateEnum = (...)
   TShiftState = set of TShiftStateEnum;
   
   ?
  
  Of course that is possible. It requires some imagination though (and
  a feel for obfuscated Pascal)
 
 
 The example fails in Delphi 6 btw, but works in FPC :-)

Interesting :)

But in this case: why not simply add one line to classes.pp?


 Delphi does not allow low/high on sets
 
 (I vote to keep this FPC extension btw)

Yes.

Mattias

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Re: [fpc-devel] TShiftState as enum

2005-02-17 Thread Marco van de Voort 
 [EMAIL PROTECTED] (Marco van de Voort) wrote:
  
  The example fails in Delphi 6 btw, but works in FPC :-)
 
 Interesting :)

Yeah, D2005 for IN syntax is also useful for this (if it operates on sets)
 
 But in this case: why not simply add one line to classes.pp?

That is not as much fun!

(But I meanwhile already committed and forwarded the tag (so it will be in
1.9.8))

  Delphi does not allow low/high on sets
  
  (I vote to keep this FPC extension btw)
 
 Yes.

I also submitted it as bug/wishlist to Borland.

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Re: [fpc-devel] TShiftState as enum

2005-02-17 Thread Nikolay Nikolov 
Jose Manuel wrote:
Well, sets are by definition a kind of bag. No enumeration or any kind of
order are suited to sets.
Can be handy, I agree, under certain situations, but then we are getting
back to C.
I think sets are sets and enumerated types are enumerated types, and Pascal
is Pascal-
 

Ok, but in pascal the elements in a set can only be of ordered type anyway.
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Re: [fpc-devel] TShiftState as enum

2005-02-17 Thread DrDiettrich 
Marco van de Voort wrote:
 
   TShiftState is defined as TShiftState = set of (...);
  
   How can I iterate through the enums? If not, can we split and add an
   enum:
  
   TShiftStateEnum = (...)
   TShiftState = set of TShiftStateEnum;
  
   ?
 
  Of course that is possible. It requires some imagination though (and a feel
  for obfuscated Pascal)
 
 The example fails in Delphi 6 btw, but works in FPC :-)
 Delphi does not allow low/high on sets
 
 (I vote to keep this FPC extension btw)

Can somebody enlighten me, what code exactly fails in D6?
What extension does FPC have, that Delphi doesn't have?

And what iteration is desired? I'd use: For Low(x) To High(x)...


Let me add some more notes, regarding Delphi compatibility:

Older Delphi (and TP?) versions implemented sets of subranges (e.g. set
of 510..515) by stripping unused bytes in front of the set. The lowest
bit in a set variable always had an ordinal value of 2^n, and above set
would occupy 2 bytes, equaling an set of (504..519). In newer Delphi
versions the lowest bit exactly corresponds to the lowest ordinal value
in the range, the above set only occupies one byte (510..517).

AFAIR D6 introduced open enums, with arbitrary (discontinuous...)
values for the members. IMO this only is an attempt to closer reflect C
enums, but sets of such enumerated types are not allowed.


I do not ask for any compatibility in these cases, in detail when the
Delphi implementation differs amongst compiler versions.

DoDi


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RE: [fpc-devel] TShiftState as enum

2005-02-17 Thread Jose Manuel 



 Can somebody enlighten me, what code exactly fails in D6?
 What extension does FPC have, that Delphi doesn't have?

 And what iteration is desired? I'd use: For Low(x) To High(x)...


 Let me add some more notes, regarding Delphi compatibility:

 Older Delphi (and TP?) versions implemented sets of subranges (e.g. set
 of 510..515)

i don't want to become heavy, but a subrange it's a subrange and a set is a
set.
If you'd use Low() and High(), your treating a set as if it were an array,
that can be handy sometimes, but strictly speaking, a set has no lower or
higher elements.
As far as I can remember, in TP, sets were represented with a single byte,
that is, the 255 bits were on or off (1 or 0) and represented the existance
or the lack of it in the set.
AFAICK, you can check for a determinate value in a set, but you can't
navigate through it as if it were an array. OK, you can use Boolean
operators (Union, Intersection, Rest...) and the Include, Exclude functions,
etc..., if you feel more comfortable. But there's no firt element, there are
no repeated elements, etc... It's a set

 AFAIR D6 introduced open enums, with arbitrary (discontinuous...)
 values for the members. IMO this only is an attempt to closer reflect C
 enums, but sets of such enumerated types are not allowed.

That's right. Enumerated open types (C-alike), such as (GREY=14, RED,
BLUE=21, ...) were introduced in D6, but anyway don?t have nothing to do
with sets.


 I do not ask for any compatibility in these cases, in detail when the
 Delphi implementation differs amongst compiler versions.

I really don't know, but I guess you are right, it must be a compiler
dependence.

JMR



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Re: [fpc-devel] TShiftState as enum

2005-02-17 Thread Peter Vreman 
 Older Delphi (and TP?) versions implemented sets of subranges (e.g. set
 of 510..515) by stripping unused bytes in front of the set. The lowest
 bit in a set variable always had an ordinal value of 2^n, and above set
 would occupy 2 bytes, equaling an set of (504..519). In newer Delphi
 versions the lowest bit exactly corresponds to the lowest ordinal value
 in the range, the above set only occupies one byte (510..517).

Supported by FPC

 AFAIR D6 introduced open enums, with arbitrary (discontinuous...)
 values for the members. IMO this only is an attempt to closer reflect C
 enums, but sets of such enumerated types are not allowed.

Supported by FPC



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Re: [fpc-devel] TShiftState as enum

2005-02-17 Thread Marco van de Voort 
  Older Delphi (and TP?) versions implemented sets of subranges (e.g. set
  of 510..515) by stripping unused bytes in front of the set. The lowest
  bit in a set variable always had an ordinal value of 2^n, and above set
  would occupy 2 bytes, equaling an set of (504..519). In newer Delphi
  versions the lowest bit exactly corresponds to the lowest ordinal value
  in the range, the above set only occupies one byte (510..517).
 
 Supported by FPC

{$mode delphi}

type aenum=510..517;
 aset = set of aenum;


begin
  Writeln(sizeof(aset));
end.

xbla.pp(5,25) Error: illegal type declaration of set elements
xbla.pp(10,4) Fatal: There were 1 errors compiling module, stopping

Redone with 200..207;- size = 32 byte = 256 element, so the behaviour
of the older version.

 

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[fpc-devel] TShiftState as enum

2005-02-16 Thread Mattias Gaertner 

TShiftState is defined as TShiftState = set of (...);

How can I iterate through the enums? If not, can we split and add an
enum:

TShiftStateEnum = (...)
TShiftState = set of TShiftStateEnum;

?

Mattias


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Re: [fpc-devel] TShiftState as enum

2005-02-16 Thread Marco van de Voort 
 TShiftState is defined as TShiftState = set of (...);
 
 How can I iterate through the enums? If not, can we split and add an
 enum:
 
 TShiftStateEnum = (...)
 TShiftState = set of TShiftStateEnum;
 
 ?

Of course that is possible. It requires some imagination though (and a feel
for obfuscated Pascal)



type myset = set of ( a1,a2,a3,a4,a5,a6);

// workaround types
const
 beginmyset=ord(low(myset));
 endmyset=ord(high(myset));
type
 uglyenum = beginmyset..endmyset;
 uglyset= set of uglyenum;

var b : myset;
i : integer;

begin
  b:=[a1,a2,a3];
  for i:=ord(low(myset)) to ord(high(myset)) do
if i in uglyset(b) then writeln(i);
end.






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Re: [fpc-devel] TShiftState as enum

2005-02-16 Thread Marco van de Voort 
  TShiftState is defined as TShiftState = set of (...);
  
  How can I iterate through the enums? If not, can we split and add an
  enum:
  
  TShiftStateEnum = (...)
  TShiftState = set of TShiftStateEnum;
  
  ?
 
 Of course that is possible. It requires some imagination though (and a feel
 for obfuscated Pascal)


The example fails in Delphi 6 btw, but works in FPC :-)
Delphi does not allow low/high on sets

(I vote to keep this FPC extension btw)

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