The Wiert Corner – irregular stream of stuff

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

  • My badges

  • Twitter Updates

  • My Flickr Stream

  • Pages

  • All categories

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

    Join 4,224 other subscribers

Archive for December 2nd, 2020

Lecture 9B | MIT 6.001 Structure and Interpretation, 1986 – YouTube

Posted by jpluimers on 2020/12/02

Great way of learning, as 1980s teachers show the power of just a chalk board for explaining things.

Holiday binge watching (and reading): Structure and Interpretation of Computer Programs. Favorite video in the series: – where the two wizard profs explain / ‘role play’ the register machine with the stack.

1980s style at its best – you don’t need infographics and animations – just a chalkboard.



Read the rest of this entry »

Posted in Development, Software Development | Leave a Comment »

Making it dead simple to implement @haveibeenpwnd in your applications, including strength warning if found in @troyhunt’s password collection.

Posted by jpluimers on 2020/12/02

I wasn’t aware that Troy Hunt created an API [WayBack] for [WayBack] Have I Been Pwned: Check if your email has been compromised in a data breach.

He did, as I noticed through [WayBack] Michelangelo van Dam on Twitter: “Making it dead simple to implement @haveibeenpwnd in my applications, including strength warning if found in @troyhunt’s password collection. Check out to try it out yourself. #ImproveSecurity #haveibeenpwnd”.

There are in fact plenty of other packages, web-sites and apps using the API as seen on [WayBack] Have I Been Pwned: API consumers.

Many people ask “if it is safe” (often assuming passwords are sent in clear, or hashes are sent in full; my fear is that those people implement security somewhere).

It is safe:

PHP source is at [WayBack] GitHub – DragonBe/hibp: A composer package to verify if a password was previously used in a breach using Have I Been Pwned API.

There is also a [WayBack] composer package at [WayBack] dragonbe/hibp – Packagist.

A really cool thing on it is this:

This project was also the subject of my talk [WayBack] Mutation Testing with Infection where the code base was not only covered by unit tests, but also was subjected to Mutation Testing using [WayBack] Infection to ensure no coding mistakes could slip into the codebase.

Apart from the tests, the most important source is at [WayBack] hibp/Hibp.php at master · DragonBe/hibp · GitHub



Posted in Development, Mobile Development, PHP, Python, Scripting, Software Development, Web Development | Leave a Comment »

Delphi spring collections

Posted by jpluimers on 2020/12/02

[WayBack] Spring Collections I have a list of elements, there are, for example, 100 of them. List : IList; I want to get 5 values greater than 10 and … – Jacek Laskowski – Google+


I have a list of elements, there are, for example, 100 of them.

List : IList<Integer>;

I want to get 5 values greater than 10 and I do it like this:

result: = List.Where(ValueIsGreatThan10).Take(5);

Will the “work loop” be executed a minimum number of times and if, for example, the first 5 values in the list will be greater than 5, then only the five will be checked? Or maybe the Where() loop will scan 100 elements, and Take() will return the first 5 results?

A (by Stefan Glienke)

Where and Take are streaming operators and only execute as much as required.

Also the operations have deferred execution. So your statement does not materialize any collection yet. Only if you iterate it will.

They are designed after the operators in .NET so the table from [WayBack] Classification of Standard Query Operators by Manner of Execution (C#) | Microsoft Docs applies. If you find any difference please report it.


  nums: IEnumerable<Integer>;
  i: Integer;
  nums := TEnumerable.Range(1, 100).Where(
    function(const i: Integer): Boolean
      Writeln('checking: ', i);
      Result := i > 10;
  Writeln('query created');
  for i in nums do
    Writeln('got number: ', i);

This code will print:

query created
checking: 1
checking: 2
checking: 3
checking: 4
checking: 5
checking: 6
checking: 7
checking: 8
checking: 9
checking: 10
checking: 11
got number: 11
checking: 12
got number: 12
checking: 13
got number: 13
checking: 14
got number: 14
checking: 15
got number: 15


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

%d bloggers like this: