The Wiert Corner – irregular stream of stuff

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

  • My badges

    Mastodon

  • Twitter Updates

  • Pages

  • All categories

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 1,839 other subscribers

Archive for the ‘Development’ Category

« Previous Entries
Next Entries »

It was all Greek to me: Iota · golang/go

Posted by jpluimers on 2019/05/21

Context is king!

Being Dutch, my association with iota was the phrase “Ik snap er geen iota van” (English: “It’s all Greek to me”), basically indicating iota is extremely small, similar to [WayBack] Iota | Definition of Iota by Merriam-Webster:

1: an infinitesimal amount : jot  (did not show an iota of interest)
2: the 9th letter of the Greek alphabet — see alphabet table

But the first time, I saw iota used in golang, I actually confused it with [WayBack] itoa – C++ Reference, because I am more than slightly wordblind.

So code like this was all Greek to me at first, not understanding the conversion from integer to ASCII**, and slightly later, not understanding iota to be extremely small either. Heck, its usage indicates it is small from infinitesimal:

const (
    _           = iota // ignore first value by assigning to blank identifier
    KB ByteSize = 1 << (10 * iota)
    MB
    GB
    TB
    PB
    EB
    ZB
    YB
)

So it took me a bit of thought to realise that it actually had to mean something completely different, so I found

It makes me wonder why they named it like this.

Slightly related:

–jeroen

Read the rest of this entry »

Posted in C++, Development, Go (golang), Software Development | Leave a Comment »

draft-ietf-appsawg-http-forwarded-10 – Forwarded HTTP Extension (X-Forwarded-For, X-Forwarded-By, and X-Forwarded-Proto)

Posted by jpluimers on 2019/05/21

Since many HTTP stacks do not have fields for this so it’s hard to get the originating IP address:

It is about these HTTP header fields with and without X- prefix:

  • Forwarded
  • X-Forwarded-For
  • X-Forwarded-By
  • X-Forwarded-Proto

Note that widely used tools like HAProxy do not always fully adhere to the “standard”…

Via:

–jeroen

Posted in Communications Development, Development, HTTP, Internet protocol suite, Software Development, TCP | Leave a Comment »

Delphi XE8 introduced the dependency directive, but it’s not for Windows

Posted by jpluimers on 2019/05/21

Interesting thread that shows Delphi XE8 introduced a dependency directive: [WayBack] Just curious, in which version was the dependency directive introduced? As in procedure X; external ‘somelib’ dependecy ‘otherlib’; S… – Johan Bontes – Google+

It’s documented as of XE8: [WayBack] Procedures and Functions (Delphi) – RAD Studio: Specifying Dependencies of the Library

The earliest use I could find is in XE4 source C:\Program Files (x86)\Embarcadero\RAD Studio\11.0\source\IBX\IBIntf.pas

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

Relay based computers…

Posted by jpluimers on 2019/05/20

Cool hardware: [WayBack] click-click-click-click-click-CHUNK… – Joe C. Hecht – Google+

Sources:

–jeroen

Read the rest of this entry »

Posted in Development, Hardware Development, History | Leave a Comment »

The Initialization-Block of a unit that is part of a package. Is it run as part of DLLMain?

Posted by jpluimers on 2019/05/16

The interesting question a while back [WayBack] The Initialization-Block of a unit that is part of a package. Is it run as part of DLLMain? – Alexander Benikowski – Google+ has a simple TL;DR answer: “it depends” on the actual usage of those units.

Way more elaborate, as I dislike language stuff that you need to track down by trial and error what is actually used:

Alexander Benikowski
Well, seems so(in our case). Rootcall which triggers the initialization is:
ntdll.ldrLoadDLL
I did not mention, that the BPL is used by a DLL(DLL links against package) which means the package is loaded/initialized by the Os when the DLLMain runs. Odd combination but that seems to be the culprit here.

David Heffernan
Yes, it is triggered from DllMain. And yes, this has massive consequences for what can and cannot be done in initialization sections.

Alexander Benikowski
+David Heffernan in my case. When a packages unit is already initialized by being used from an Exe(which links to the Package), it is not from within a DLLMain.
In my case, both the Application and the dll it loads, both link to the same package. But the unit in question is unused until the DLL is loaded.

Uwe Raabe
The docs for InitializePackage say it calls the initialization parts of all contained units in the package – not only the used ones.

David Heffernan
+Alexander Benikowski​ In that scenario we have load time linking and I guess the package framework handles it differently.

David Millington
Related: don’t forget that class constructors and destructors effectively run in the initialization and finalization sections too. Restrictions or side effects apply there too. docwiki.embarcadero.com – Methods (Delphi) – RAD Studio

Stefan Glienke
+Uwe Raabe Which is not being done when you use it as runtime package. Only initialization sections from unit being used are being run. This caused us several problems in the past where 2 modules (A being the host application exe and B being some DLL that gets loaded at a later point via LoadLibrary) were using a runtime package but only B used a particular unit from the package which caused the initialization code for that unit being executed when B was loaded and hence being executed in the context of the dllmain of B.

The usual solution is then to put those units into some dummy unit forcing the initialization of that unit to be run in A.

Another solution according to your statement could be to call InitializePackage on all the used runtime packages – and there the question is: couldn’t the RTL do that somehow?

Uwe Raabe
+Stefan Glienke I am not sure if that is desirable when done unconditionally. Even when compiled with packages I wouldn’t expect units to be initialized which aren’t actually used. That would perhaps change the behavior of the application depending on whether it is compile with runtime packages or without.
The case is different with dynamic loaded packages. The units in there are obviously not directly used in the first place. As no one can know which units of such a package are used or not, initializing all of them seems like a viable decision.
Of course there will be situations where your proposed behavior might come in handy, but I doubt that this will be a fit for all.

Source: The Initialization-Block of a unit that is part of a package. Is it run as pa…

Related:

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

How to Design Early Returns in C++ (Based on Procedural Programming) – Fluent C++

Posted by jpluimers on 2019/05/15

One more thing to take away from Procedural Programming: It’s Back? It Never Went Away – Kevlin Henney [ACCU 2018] – YouTube was explained in [WayBack] How to Design Early Returns in C++ (Based on Procedural Programming) – Fluent C++.

Though in C++, it applies to all programming languages that stem from a procedural background (Pascal, C#, Java, golang, to name just a few).

The article is about keeping an if/else-if/else tree, even when they can be removed becomes some of their bodies perform an early return, as

In C++, as well as in other languages, the return keyword has two responsibilities:

  • interrupting control flow,
  • yielding a value.

It basically comes down to this argument:

Essentially, the argument for Code #1 is that you need to know less to understand the structure of the code.

Indeed, if we fold away the contents of the if statements, Code #1 becomes this:

The structure of the code is very clear. There are 4 different paths based on the year, they’re independent from each other, and each path will determine the boolean result of the function (if it doesn’t throw an exception).

Now let’s see how Code #2 looks like when we fold away the if statements:

And now we know much less. Do the if statements contain a return? Maybe.

Do they depend on each other? Potentially.

Do some of them rely on the last return false of the function? Can’t tell.

With Code #2, you need to look inside of the if statement to understand the structure of the function. For that reason, Code #1 requires a reader to know less to understand the structure. It gives away information more easily than Code #2.

–jeroen

via [WayBack] Kevlin Henney – Google+: How to Design Early Returns in C++ (Based on Procedural Programming) – Fluent C++

Posted in .NET, C, C#, C++, Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »

Need to try this: overloaded default properties

Posted by jpluimers on 2019/05/15

[Archive.is] Need to try this: … multiple default index properties having the same name …getters can be overloads … resolve …by type signature … – Thomas Mueller (dummzeuch) – Google+, thanks to marck for this brilliantly simple example:

private
  function GetColumnValue(const ColumnName: string): string; overload;
  function GetColumnValue(Index: Integer): string; overload;
  procedure SetColumnValue(Index: Integer; const Value: string);
public
  property Values[const ColumnName: string]: string read GetColumnValue; default;
  property Values[ColumnIndex: Integer]: string read GetColumnValue write SetColumnValue; default;
end;

This means:

  • you can have multiple default indexor properties
  • the multiple indexor properties can have the same name e.g., Values
  • the properties getters can be overloads (i.e. have the same name) e.g., GetColumnValue
  • Delphi will resolve the overloads by type signature

–jeroen

Posted in Delphi, Development, Software Development | Leave a Comment »

Time capsule opening ceremony today at MIT’s Stata Center after programmers solve MIT’s 20-year-old cryptographic puzzle | MIT CSAIL

Posted by jpluimers on 2019/05/15

[WayBack] Programmers solve MIT’s 20-year-old cryptographic puzzle | MIT CSAIL:

The capsule ceremony will happen Wednesday, May 15 at 4 p.m. at MIT’s Stata Center.

Cool work, with a very cool challenge.

Via/related:

  • a

–jeroen

Posted in Development, Power User, Security, Software Development | Leave a Comment »

On the Effectiveness of Static Typing in Detecting Public Bugs

Posted by jpluimers on 2019/05/14

Cool research paper from a while back but still soo relevant:

The project page for an ICSE’17 paper, To Type or Not to Type: Quantifying Detectable Bugs for JavaScript

JavaScript is also a dynamically typed language for which static type systems, notably Facebook’s Flow and Microsoft’s TypeScript, have been written. What benefits do these static type systems provide?

Source: [Archive.is] On the Effectiveness of Static Typing in Detecting Public Bugs

 

Other saved links:

–jeroen

via: [WayBack/Archive.is] Slashdot drew my attention to this ressearch … http://ttendency.cs.ucl.ac.uk/projects/type_study/ An argument for languages like Delphi. – Roland Kossow – Google+

Posted in Development, JavaScript/ECMAScript, Scripting, Software Development, TypeScript | Leave a Comment »

if statement – How to ask for batch file user input with a timeout – Stack Overflow

Posted by jpluimers on 2019/05/14

The trick is to use the choice command; see [WayBack] if statement – How to ask for batch file user input with a timeout – Stack Overflow

–jeroen

Posted in Batch-Files, Development, Microsoft Surface on Windows 7, Power User, Scripting, Software Development, Windows, Windows 10, Windows 7, Windows 8, Windows 8.1, Windows 9, Windows Server 2000, Windows Server 2003, Windows Server 2003 R2, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Vista, Windows XP | Leave a Comment »

« Previous Entries
Next Entries »