Hi:

The code below can't compiled in Delphi 5 but can be compiled in Delphi 
2007:

procedure TForm1.Button1Click(Sender: TObject);
var
  a, b : string;
begin
  a <> b;
end;

Any thoughts?

Roland

Roland Zhang wrote:

> The code below can't compiled in Delphi 5 but can be compiled in
> Delphi 2007:
> 
> procedure TForm1.Button1Click(Sender: TObject);
> var
>  a, b : string;
> begin
>  a <> b;
> end;
> 
> Any thoughts?

I haven't looked if this is in QC, but this is fixed in Delphi 2009.
With Delphi 2007 this repeats, but only at the beginning of a proc.

That

  begin
    a <> b;
    a <> b;
  end;

doesn't compile.


Since the code for

  a <> b;

is equal to

  if a <> b then;

except the additional

  setnz al

I see no big problem with this bug.
-- 
Uwe

>> The code below can't compiled in Delphi 5 but can be
>> compiled in Delphi 2007:
>> 
>> procedure TForm1.Button1Click(Sender: TObject);
>> var
>>  a, b : string;
>> begin
>>  a <> b;
>> end;

"Uwe Schuster" <jedivcs@bitcommander.de> wrote
> I haven't looked if this is in QC, but this is fixed in Delphi 2009.
> With Delphi 2007 this repeats, but only at the beginning of a proc.
> ...
> I see no big problem with this bug.

I see a little problem. --JohnH

Thank you for your input.

We got big problem with this bug, with this, the value was not assigned. Of 
course not big problem if we test thoroughly.

Roland


"Uwe Schuster" <jedivcs@bitcommander.de> wrote in message 
news:82707@forums.codegear.com...
> Roland Zhang wrote:
>
>> The code below can't compiled in Delphi 5 but can be compiled in
>> Delphi 2007:
>>
>> procedure TForm1.Button1Click(Sender: TObject);
>> var
>>  a, b : string;
>> begin
>>  a <> b;
>> end;
>>
>> Any thoughts?
>
> I haven't looked if this is in QC, but this is fixed in Delphi 2009.
> With Delphi 2007 this repeats, but only at the beginning of a proc.
>
> That
>
>  begin
>    a <> b;
>    a <> b;
>  end;
>
> doesn't compile.
>
>
> Since the code for
>
>  a <> b;
>
> is equal to
>
>  if a <> b then;
>
> except the additional
>
>  setnz al
>
> I see no big problem with this bug.
> -- 
> Uwe

Roland Zhang wrote:

> Uwe Schuster wrote:
>
> > Roland Zhang wrote:
> > 
> > > The code below can't compiled in Delphi 5 but can be compiled in
> > > Delphi 2007:
> > > 
> > > procedure TForm1.Button1Click(Sender: TObject);
> > > var
> > >   a, b : string;
> > > begin
> > >   a <> b;
> > > end;
> > > 
> > > Any thoughts?
> > 
> > I haven't looked if this is in QC, but this is fixed in Delphi 2009.
> > With Delphi 2007 this repeats, but only at the beginning of a proc.
> 
> We got big problem with this bug, with this, the value was not
> assigned.

Huh? The code above does almost nothing, what didn't get assigned?


-- 
Pieter

"Getting an education was a bit like a communicable sexual disease. 
 It made you unsuitable for a lot of jobs and then you had the urge
 to pass it on." -- Terry Pratchett, Hogfather

We supposed to write a := b; while accidentely write a <> b and not noticed 
it(never thought this could compile successfully);

Roland


"Pieter Zijlstra" <p.zylstra.notthis@hccnet.nl> wrote in message 
news:82737@forums.codegear.com...
> Roland Zhang wrote:
>
>> Uwe Schuster wrote:
>>
>> > Roland Zhang wrote:
>> >
>> > > The code below can't compiled in Delphi 5 but can be compiled in
>> > > Delphi 2007:
>> > >
>> > > procedure TForm1.Button1Click(Sender: TObject);
>> > > var
>> > >   a, b : string;
>> > > begin
>> > >   a <> b;
>> > > end;
>> > >
>> > > Any thoughts?
>> >
>> > I haven't looked if this is in QC, but this is fixed in Delphi 2009.
>> > With Delphi 2007 this repeats, but only at the beginning of a proc.
>>
>> We got big problem with this bug, with this, the value was not
>> assigned.
>
> Huh? The code above does almost nothing, what didn't get assigned?
>
>
> -- 
> Pieter
>
> "Getting an education was a bit like a communicable sexual disease.
> It made you unsuitable for a lot of jobs and then you had the urge
> to pass it on." -- Terry Pratchett, Hogfather

Roland Zhang wrote:

> We supposed to write a := b; while accidentely write a <> b and not
> noticed it (never thought this could compile successfully);
> 

Looking at my keyboard, I'm still trying to figure out how someone
could accidently type "<>" instead of ":=" even thinking about just "="
or an ex-C programmer wanting to type "!=". I can only assume that it
was a Monday morning action.

The compiler can do a lot, but it won't safe you from these Monday
morning actions ;-)

-- 
Pieter

"The dangerous patriot ... is a defender of militarism and its
 ideals of war and glory."
 -- Colonel James A. Donovan, Marine Corps

Roland Zhang wrote:

> We got big problem with this bug, with this, the value was not
> assigned.

In this case you should have provided a better example, because
  
  var
    a, b: string;
  begin
    a := b;

would make no sense. Strings are always empty.

A bit more realistic would be

  procedure DoSomething(const AInputStr: string);
  var
    TempStr: string;
  begin
    TempStr <> AInputStr;
  end;
-- 
Uwe

I just want show that this is a compiler bug, that's all. The code is 
meaningless.

Roland

"Uwe Schuster" <jedivcs@bitcommander.de> wrote in message 
news:84158@forums.codegear.com...
> Roland Zhang wrote:
>
>> We got big problem with this bug, with this, the value was not
>> assigned.
>
> In this case you should have provided a better example, because
>
>  var
>    a, b: string;
>  begin
>    a := b;
>
> would make no sense. Strings are always empty.
>
> A bit more realistic would be
>
>  procedure DoSomething(const AInputStr: string);
>  var
>    TempStr: string;
>  begin
>    TempStr <> AInputStr;
>  end;
> -- 
> Uwe

Pieter:

It's quite often we do like this:

if aaaaaaaaaaaaaaaaaaaaa <> bbbbbbbbbbbbbbbbbbbbbbbbbb then
  aaaaaaaaaaaaaaaaaaaaa := bbbbbbbbbbbbbbbbbbbbbbbbbb;

what we did is copy "aaaaaaaaaaaaaaaaaaaaa <> bbbbbbbbbbbbbbbbbbbbbbbbbb"
and past "aaaaaaaaaaaaaaaaaaaaa <> bbbbbbbbbbbbbbbbbbbbbbbbbb" but forgot 
change the operator.

You can blame programmers make such silly mistake, but the compiler itself 
is the core problem.

Roland



"Pieter Zijlstra" <p.zylstra.notthis@hccnet.nl> wrote in message 
news:83796@forums.codegear.com...
> Roland Zhang wrote:
>
>> We supposed to write a := b; while accidentely write a <> b and not
>> noticed it (never thought this could compile successfully);
>>
>
> Looking at my keyboard, I'm still trying to figure out how someone
> could accidently type "<>" instead of ":=" even thinking about just "="
> or an ex-C programmer wanting to type "!=". I can only assume that it
> was a Monday morning action.
>
> The compiler can do a lot, but it won't safe you from these Monday
> morning actions ;-)
>
> -- 
> Pieter
>
> "The dangerous patriot ... is a defender of militarism and its
> ideals of war and glory."
> -- Colonel James A. Donovan, Marine Corps

"Roland Zhang" 
> what we did copy "aaaaa <> bbbbb"
> and paste "aaaaa <> bbbbb" 
> but forgot change the operator.

I have done that. 
 
That the compiler would compile "a<>b;" is a problem that should be 
looked at, if it has not examined already.  It might be a symptom of
a problem causing less obvious, but more important bad results.    
--JohnH

Roland Zhang wrote:

> I just want show that this is a compiler bug, that's all. The code is
> meaningless.

Generally I don't share this opinion, but I don't want to discuss this
now. I have the impression that there are enough threads in this
newsgroups which discuss how bugs should be reported.
-- 
Uwe

Roland Zhang wrote:

> It's quite often we do like this:
> 
> if a <> b then
>  a := b;
> 
> what we did is copy "a <> b" and past "a <> b" but forgot change
> the operator.

Ah I see, I usually have it the other way around with, by class
completion generated, property setters, not that I really forget them
because error insight has already put a swiggly line underneath it.

> You can blame programmers make such silly mistake, but the compiler
> itself is the core problem.

BTW this is already fixed in D2009.

-- 
Pieter

"For if he like a madman lived, At least he like a wise one died."
 -- Cervantes.