Hi,
The other "arrays" discussion got me thinking, and after working so
long with only desktop type applications that talk to database API's,
I long some knowledge of the lower lever Pascal features that was so
often used in Turbo Pascal days.
Anyway, I'm port an application that was written for
Graeme Geldenhuys schrieb:
>
>
> 1) Why would you use a pointer to an array and not simply a variable
> what IS the array? In the program I am porting the following field
> variable is defined.
>
> FLines: ^TLinesArray;
>
> Why couldn't I simply say:
>
> FLines: TLinesArray;
Because thi
In our previous episode, Matthias Klumpp said:
> > also be in 2.4.0
>
> I do not have problems with FPC 2.3.x, but it is not allowed for me to use
> experimental SVN software :-(
> Early next year sounds good!
It's not experimental anymore, it now has a "fixes" branch label :-)
__
Hello,
> 2. For the purposes of reserving memory in block sizes that can be
> easily reallocated, I like to use powers of two. So if I have, e.g., a
> dynamic array, I might start with a size of 1024 and then double it
> when it hits capacity. Hopefully this smoothes memory management, as I
>
mar...@stack.nl:
> In our previous episode, "Vinzent Höfler" said:
> >
> > One thing I think you don't understand is that arrays and pointers are
> > orthogonal concepts in almost every other programming language than C.
> >
> > So technically, C is the one who got it wrong.
>
> Wrong and right
Henry Vermaak :
> Thanks for the explanation, I was under the impression that arrays in
> Pascal were similar to C. How do you explain the "automatic"
> dereferencing with a pointer to an array that Jürgen is talking about?
Those are dynamic arrays, IOW pointers disguised as arrays. This is part
Henry Vermaak :
> 2009/10/10 "Vinzent Höfler" :
> > Henry Vermaak :
> >
> >> One thing I think you don't understand is that an array _is_ a
> >> pointer. Look at this table to visualise:
> >>
> >> http://en.wikipedia.org/wiki/C_syntax#Accessing_elements
> >
> > One thing I think you don't underst
2009/10/10 Jürgen Hestermann :
>> I can't understand what you are trying to say. An array is a pointer
>> to where the elements of the array resides in memory. How else do you
>> think it works?
>
> just look at:
>
> type ArrayType = array[1..10] of char;
> var X : ArrayType;
> PX : ^ArrayT
2009/10/11 "Vinzent Höfler" :
> Henry Vermaak :
>
>> Thanks for the explanation, I was under the impression that arrays in
>> Pascal were similar to C. How do you explain the "automatic"
>> dereferencing with a pointer to an array that Jürgen is talking about?
>
> Those are dynamic arrays, IOW poi
On 11/10/2009, Henry Vermaak wrote:
> >
> > Sizeof(X) is 10 bytes.
> > Sizeof(PX) is 4 bytes.
> >
> > Still you can use X[1] and PX[1]. That's illogical.
>
>
> I've tested this now and could only get this behaviour with {$mode delphi}.
So what did the other modes return? objfpc?
--
Regar
2009/10/11 Graeme Geldenhuys :
> On 11/10/2009, Henry Vermaak wrote:
>> >
>> > Sizeof(X) is 10 bytes.
>> > Sizeof(PX) is 4 bytes.
>> >
>> > Still you can use X[1] and PX[1]. That's illogical.
>>
>>
>> I've tested this now and could only get this behaviour with {$mode delphi}.
>
> So what did
On Sun, Oct 11, 2009 at 02:01:35PM +0200, "Vinzent H?fler" wrote:
> > >
> > > So technically, C is the one who got it wrong.
> >
> > Wrong and right are absolute terms.
>
> Yes. And first mixing arrays with pointers and then telling everybody that
> this is just the same is - wrong. Absolutely.
2009/10/11 "Vinzent Höfler" :
> Henry Vermaak :
>
>> 2009/10/10 "Vinzent Höfler" :
>> > Henry Vermaak :
>> >
>> >> One thing I think you don't understand is that an array _is_ a
>> >> pointer. Look at this table to visualise:
>> >>
>> >> http://en.wikipedia.org/wiki/C_syntax#Accessing_elements
>>
In general I use pointers to data structures and especially when they
are arrays.
Take the following
PIntArray: ^TIntArray;
TIntArray:Array of Integer;
1st benefit:
declaring methods associated with classes before TIntArray needs to be
defined or declared.
eg. procedure DoSomething(Var Data
Henry Vermaak :
> Please don't confuse your opinion with "right" and "wrong".
It's not just my opinion, that arrays and pointer are different things. One
might say it's a fact.
> Confusion and consistency were what this discussion was about.
Confusing code may have many properties. But I doubt
Marco van de Voort :
> And the criticism about introducing Cisms in FPC/Delphi is also old. In
> the past I would have joined you, but after a few non-trivial header
> conversions and library conversions that pretty much died out.
Yes. But that's not the fault of the C-language. That's the fault
In our previous episode, "Vinzent H?fler" said:
> > And the criticism about introducing Cisms in FPC/Delphi is also old. In
> > the past I would have joined you, but after a few non-trivial header
> > conversions and library conversions that pretty much died out.
>
> Yes. But that's not the fault
2009/10/11 "Vinzent Höfler" :
> Henry Vermaak :
>
>> Please don't confuse your opinion with "right" and "wrong".
>
> It's not just my opinion, that arrays and pointer are different things. One
> might say it's a fact.
You said C did it "wrong", because you think that arrays and pointers
should be
Henry Vermaak schrieb:
> 2009/10/11 "Vinzent Höfler" :
>> Henry Vermaak :
>>
>>> Thanks for the explanation, I was under the impression that arrays in
>>> Pascal were similar to C. How do you explain the "automatic"
>>> dereferencing with a pointer to an array that Jürgen is talking about?
>> Thos
On 11/10/2009, Andrew Brunner wrote:
> FPC forces the ^ operator while accessing structures as pointers.
> Delphi didn't force it and I even suspect that memory leaks can result
> in NOT using the ^ to denote the reference to the pointer rather than
> the pointer itself.
This was just discuss
On Sun, 11 Oct 2009 11:09:58 +0200 (CEST), mar...@stack.nl (Marco van de
Voort) wrote:
> In our previous episode, Matthias Klumpp said:
>> > also be in 2.4.0
>>
>> I do not have problems with FPC 2.3.x, but it is not allowed for me to
>> use
>> experimental SVN software :-(
>> Early next year soun
Andrew Brunner :
> 1st benefit:
>
> declaring methods associated with classes before TIntArray needs to be
> defined or declared.
> eg. procedure DoSomething(Var Data:TIntArray); vs (DataP:PIntArray);
Huh? Is there any difference other than the second one can take a NIL value?
> Lastly, passi
I came across this link by chance. Wow, I never knew there was that
many Pascal Compiler implementations. A lot!
http://pascaland.org/pascall.htm
--
Regards,
- Graeme -
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mar...@stack.nl:
> > That simply means, the code is not documented. Again: Not entirely C's
> fault.
>
> Docs. Like anybody reads them.
Well, I do. If the coder cares to write any, that is. :)
Vinzent.
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Henry Vermaak :
> You said C did it "wrong", because you think that arrays and pointers
> should be different things.
No, I said so, because arrays and pointers *are* different things (even in C
there are subtle differences - which should sort of prove my point).
Apart from that, I expect my re
At 03:25 PM 10/11/2009, Graeme Geldenhuys wrote:
I came across this link by chance. Wow, I never knew there was that
many Pascal Compiler implementations. A lot!
http://pascaland.org/pascall.htm
Well, reduce it to the compilers that are still maintained, and the
list is far less impressive...
Remember, Pascal is merely a TEACHING language, unsuitable for commercial
software development, which is why we have C. :)
On Sunday 11 October 2009 05:00:04 pm Ralf A. Quint wrote:
> At 03:25 PM 10/11/2009, Graeme Geldenhuys wrote:
> >I came across this link by chance. Wow, I never knew there w
At 05:27 PM 10/11/2009, Mark Emerson wrote:
Remember, Pascal is merely a TEACHING language, unsuitable for commercial
software development, which is why we have C. :)
Yeah, right... >:-}
Ralf ;-)
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