The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Delphi 2009’ Category

Delphi: `with` dos and dont’s (more of the latter though).

Posted by jpluimers on 2014/02/18

About a year ago, I wrote about Delphi: you should avoid the with statement as it makes your code less future proof. Then I already tweeted I would follow up. Time to do it now (:

Besides my first post, these links inspired me most:

Posts about the with statement usually cause a stir: people either like or dislike it with passion.

Starting with some history and examples, this posts lists a few DOs and DON’Ts when using the with statement, shows advantages and drawbacks, and shows you tools to eliminate with statements. Read the rest of this entry »

Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Development, Pascal, Software Development, Turbo Pascal, With statement | 9 Comments »

Do not share DCU files between projects (via: delphi – Compiler Directive IF and IFEND – Stack Overflow)

Posted by jpluimers on 2014/02/13

Summary: Always try to avoid sharing .DCU files between projects.

I see a lot of projects at clients that do not have their individual DCU directories set (therefore having the DCU files in the same directory as the PAS files causing shared units to share the DCU files), or share DCU files among different projects.

Both are a very bad idea, as the compiler does not always understand when the DCU file does not match the combination of PAS file and compiler options.

The result is the occasional use of the DCU file in stead of the PAS file causing wrong code to be used, or wrong debugger information to be included.

Danny Thorpe phrased it on Stack Overflow: Read the rest of this entry »

Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Development, FreePascal, Lazarus, Pascal, Turbo Pascal | 9 Comments »

delphi – With a class operator is an implicit typecast to itself allowed? – Stack Overflow

Posted by jpluimers on 2014/01/29

In the series “interesting stuff you can do with Implicit operators”: delphi – With a class operator is an implicit typecast to itself allowed? – Stack Overflow.

Be careful though, as Implicit assignment will allow more code paths to the compiler than you expect at first sight (:

–jeroen

Posted in Delphi, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Software Development | Leave a Comment »

DelphiSpec Library Announce « Роман.Янковский.me

Posted by jpluimers on 2013/12/22

Cool stuff: DelphiSpec library, inspired by Cucumber. It runs on top of DUnit.

via DelphiSpec Library Announce « Роман.Янковский.me.

A similar one in the .NET realm: SpecFlow – Pragmatic BDD for .NET.

–jeroen

Posted in .NET, .NET 3.5, .NET 4.0, .NET 4.5, C#, C# 3.0, C# 4.0, C# 5.0, Delphi, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Software Development | Leave a Comment »

XOR swap/exchange: nowadays an almost extinct means to exchange two distinct variables of the same size

Posted by jpluimers on 2013/12/19

Almost a year ago, a thread on “premature Delphi optimization” came by on G+ about this code:

procedure ExchangeInteger(var AValue1, AValue2: Integer);
begin
  AValue1 := AValue1 xor AValue2;
  AValue2 := AValue1 xor AValue2;
  AValue1 := AValue1 xor AValue2;
end;

I don’t think that was premature optimization, just some code from an old fart that had already been programming in the era where processors had reasons to use it:

Back then, the only efficient way to exchange two variables of the same data type was using the XOR swap algorithm.

Nowadays you have more options, and this is where the fun in that thread began, which I will show in a minute.

First a bit of history

The XOR swap algorithm was widely known in the 80s of last century and before, especially because the 6502 processor (oh the days of LISA Assembler) was vastly popular, as was the Z80. Together, they powered the majority of the home computers in the 70s and 80s.

Read the rest of this entry »

Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Development, History, Pascal, Software Development, Turbo Pascal, UCSD Pascal | 7 Comments »

Delphi postbuild events: interesting take by David Heffernan (via: Stack Overflow)

Posted by jpluimers on 2013/12/12

StackOverflow user David Heffernan – Stack Overflow has an interesting take on Delphi postbuild events:

At the moment my actiona read:

if exist PostBuild.bat call PostBuild.bat $(Platform) $(Config) $(OutputDir)

And then the PostBuild.bat script calls a Python script so that I can write my scripts in a real language.

I actually impose the build actions in a shared option set that I reference from all of my projects. That way I enforce consistency and predictability.

I know others use tools like FinalBuilder but building is so important that I feel it’s worth my effort in rolling my own tooling.
– David Heffernan Feb 14 at 20:24

–jeroen

via: Delphi XE3: Problems with complex pre-build events – Stack Overflow.

Posted in Delphi, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Development, Software Development | Leave a Comment »

When the Delphi XE5 commandline compiler fails with `error F1026: File not found: ‘False.dpr’`

Posted by jpluimers on 2013/11/20

If you an error like below when compiling Delphi XE5 .dproj files using msbuild … then note the documentation for Debug information (Delphi) – RAD Studio. has not been updated yet as it still lists the values {$D+} or {$D-} {$DEBUGINFO ON} or {$DEBUGINFO OFF}.

(_PasCoreCompile target) -> C:\Program Files (x86)\Embarcadero\RAD Studio\12.0\Bin\CodeGear.Delphi.Targets(187,5): error F1026: File not found: 'False.dpr'

With Delphi XE5, you can specify 3 additional values: {$D1}{$D2} and {$D0}, or {$DEBUGINFO 1}{$DEBUGINFO 2} or {$DEBUGINFO 0}

In the msbuild .dproj files , the values are stored as DCC_DebugInformation elements. Read the rest of this entry »

Posted in Delphi, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Missed Schedule, SocialMedia, Software Development, WordPress | 13 Comments »

Delphi – Direct3D and the wrong FPU state: Now() function returns a wrong value (via: StackOverflow)

Posted by jpluimers on 2013/10/31

The question datetime – Delphi Now() function returns a wrong value – Stack Overflow is similar to my article Delphi – Michael Justin had strange floating point results when his 8087 FPU Control Word got hosed.

Good that stackoverflow user Anton Zhuchkov found out the cause himself: his answer indicates the Precision Control (and rounding) part of the FPU state got hosed by wrongly initializing the Direct3D device.

I edited his answer with some extra links to documentation.

Finally I’ve found the solution. I needed to specify the D3DCREATE_FPU_PRESERVE flag when creating a D3D device by D3D.CreateDevice.

Otherwise, without that flag, all floating point operations are performed with single precision. As the TDateTime is a simple Double, and Now() functions is consist of simple addition of date value to time value, it all get messed up by DirectX “smart” override.

Problem solved. It was a tricky one indeed. :)

–jeroen

via: datetime – Delphi Now() function returns a wrong value – Stack Overflow.

Posted in 8087, Algorithms, Delphi, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 5, Delphi 6, Delphi 7, Delphi XE, Delphi XE2, Delphi XE3, Development, Floating point handling, Software Development | 2 Comments »

.NET/C#/VB.net: some links on ExpandoObject

Posted by jpluimers on 2013/10/10

Still a C# 4.0 / .NET 4 feature that I need to investigate more deeply: ExpandoObject, partially because I had very bad memories of Variant support in Delphi.

So here are a few links.

First of all: since VB.NET already does late binding with the Object keyword, you cannot use ExpandoObject with Strict On in VB.NET 10.0 and up:

Now the C# links:

–jeroen

Posted in .NET, .NET 4.0, .NET 4.5, C#, C# 4.0, C# 5.0, Delphi, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi XE, Delphi XE2, Delphi XE3, Development, Software Development | 5 Comments »

XSD/XML Schemas: resolving `Namespace ” is not available to be referenced in this schema` (via: StackOverflow)

Posted by jpluimers on 2013/09/01

While working on my Delphi: First try on an XSD for .groupproj files, I bumped into an error `Namespace ” is not available to be referenced in this schema`.

I added a targetNamespace attribute to the GroupProj.xsd so the .grouproj files would use the right namespace.

That resulted into two funny errors:

  1. Namespace ” is not available to be referenced in this schema.
    Visual Studio (which I normally use for editing XSD) would only throw this error on these elements:
    <xsd:element ...>
    So it would not throw them on nodes using the empty namespace.
    That was really confusing!
  2. When validating .grouproj files using this GroupProj.xsd, I would get this error for all .groupproj files:
    System.Xml.Schema.XmlSchemaValidationException: Type ‘<type>’ is not declared. (in this case for ‘<type>’  ‘ProjectType’).
    That was odd too: the ‘ProjectType’ was indeed declared, and should be valid.

I could hardly find any information about the latter error, but the former gave a few useful hits.

Thanks User weston – Stack Overflow. for answering this: it made me smack to my head (like usual, a case of EBCAK). Read the rest of this entry »

Posted in Delphi, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Software Development, XML/XSD, XSD | Tagged: , , | 2 Comments »