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 ‘Development’ Category

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A series of Medium posts introducing functional programming in manageable bits and pieces

Posted by jpluimers on 2020/09/30

I have summarised the main topics of each part in this table of contents, and indicated at the time of writing which parts I did not get yet:

  1. [WayBack] So You Want to be a Functional Programmer (Part 1) – Charles Scalfani – Medium
    • pure functions (only operate on input parameters: without side effects)
    • immutability (no variables! loops through recursion)
  2. [WayBack] So You Want to be a Functional Programmer (Part 2) – Charles Scalfani – Medium
    • refactoring leads to the need of higher-order functions
    • higher-order functions: passing a function as a parameter, or returning functions as a result
    • closure: when a returned function has access to the captured parameter(s) of the function creating the returned function
  3. [WayBack] So You Want to be a Functional Programmer (Part 3) – Charles Scalfani – Medium
    • functional decomposition (I still need to wrap my head around this)
    • point-free notation (same)
    • both lead to currying (which I also need to wrap my head around)
  4. [WayBack] So You Want to be a Functional Programmer (Part 4) – Charles Scalfani – Medium
    • currying: when you want to combine functions having different parameter counts
    • refactoring based on currying (I still need to wrap my head around this)
    • map/filter/reduce functional building blocks (I still need to wrap my head around this)
  5. [WayBack] So You Want to be a Functional Programmer (Part 5) – Charles Scalfani – Medium
    • referential transparency (I still need to wrap my head around this)
    • execution order: in a pure functional language the compiler can determine the order when functions are completely independent
    • type annotation: I do not yet get why you would do without this
  6. [WayBack] So You Want to be a Functional Programmer (Part 6) – Charles Scalfani – Medium
    • Functional JavaScript and ELM: two functional languages, of which Ramba can help make better JavaScript code

Via: [WayBack] So You Want to be a Functional Programmer (Part 1) Link to part 2 in the article. https://medium.com/@cscalfani/so-you-want-to-be-a-functional-programm… – Lars Fosdal – Google+

–jeroen

Posted in Conference Topics, Conferences, Development, Event, Functional Programming, Software Development | Leave a Comment »

When your ORM does not support string concatenation by || or + operator…

Posted by jpluimers on 2020/09/30

If your ORM does not support string concatenation by operator (standard double pipe || or non-standard plus +), you can usually revert to the CONCAT function.

Very often, the CONCAT function supports more than 2 parameters.

References:

–jeroen

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

When did we stop caring about memory management? – Scott Hanselman

Posted by jpluimers on 2020/09/29

Still relevant [WayBack] When did we stop caring about memory management? – Scott Hanselman

Via: [WayBack] Jeroen Wiert Pluimers – Google+

–jeroen

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Posted in Development, Software Development | Leave a Comment »

variables – What is “_,” in a Golang declaration? – Stack Overflow

Posted by jpluimers on 2020/09/29

As a (then) go lang n00b, the less upvoted answers helped me e lot: [WayBack] variables – What is “_,” in a Golang declaration? – Stack Overflow:

  • The Go compiler won’t allow you to create variables that you never use.

    for i, value := range x {
   total += value
}

    The above code will return an error message “i declared and not used”.

    Since we don’t use i inside of our loop we need to change it to this:

    for _, value := range x {
   total += value
}

  • _ is the blank identifier. Meaning the value it should be assigned is discarded.

    Here it is the value of example key that is discarded. The second line of code would discard the presence boolean and store the value in prs.
    So to only check the presence in the map, you can discard the value. This can be used to use a map as a set.

–jeroen

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

Visual Studio Code on Mac and Linux can also use the mssql extension

Posted by jpluimers on 2020/09/29

Cool, this works in a Mac and Linux too: mssql extension for VS Code.

Links:

–jeroen

Posted in .NET, Database Development, Development, Software Development, SQL Server, Visual Studio and tools, vscode Visual Studio Code | Leave a Comment »

Viewing a USB WebCam on Windows 10 without any fuzz

Posted by jpluimers on 2020/09/28

Windows 10 comes with a broken Camera viewer and before that, Windows 7 killed the one in Windows XP.

On a Mac you have the open source Quick Camera (which named QCamera before, seeViewing an USB camera on Mac OS X without mirroring and Capturing from a Magewell XI100USB on a Mac using OS X) at [WayBack] GitHub – simonguest/quick-camera.

For Windows 7, a long search initially revealed a lot of bloat-ware, but finally ended to these two both from the same author:

It is not open source (yet?), but since it is .NET, it is reasonable easy to see the innards.

Like QCamera, it does not require installation: just unzip and run. Enjoy!

Yes, I know there are Windows 10 workaround steps via Microsoft.CameraApp.App.ctor, but if you look at [WayBack] Win10 Home N – Camera App fails: System.IO.FileNotFoundException – Microsoft Community you will understand I did not apply them.

Similarly, when you install Skype from the app store, then sign-in, it will tell you that Skype is out of date.

–jeroen

via:

Posted in .NET, Apple, Development, Mac OS X / OS X / MacOS, Power User, Software Development, Windows | Leave a Comment »

Windows 7 Blue Screen Of Death with error 0x7B – twm’s blog

Posted by jpluimers on 2020/09/28

[WayBack] Windows 7 Blue Screen Of Death with error 0x7B – twm’s blog:

To allow Windows 7 to boot in IDE as well as AHCI mode, I had to enable the following drivers (by setting “Start” to “0” in the registry, there might be other options to do this):

HKLM\System\CurrentControlSet\services\intelide
HKLM\System\CurrentControlSet\services\pciide
HKLM\System\CurrentControlSet\services\msahci
HKLM\System\CurrentControlSet\services\iastorV

The first two allow Windows 7 to boot from SATA in IDE mode. The second two allow Windows 7 to boot from SATA in AHCI mode.

–jeroen

Posted in Development, Power User, Windows, Windows 10, Windows 7, Windows 8, Windows 8.1, Windows 9 | Leave a Comment »

Delphi – The use of AlignAttribute: indicate the alignment of a field

Posted by jpluimers on 2020/09/25

Great answer by Stefan Glienke at [WayBack] What’s the use of AlignAttribute? The documentation only says Internal use only.  – 丽丽乌克 – Google+:

It forces the element it annotates to be aligned like specified – valid values are the same as for $A (1, 2, 4, 8, 16)

Example:

{$A4}
type
  TMyRecordA = record
    x: Integer;
    y: Int64;
  end;

  TMyRecordB = record
    x: Integer;
    [Align(8)]
    y: Int64;
  end;
var
  a: TMyRecordA;
  b: TMyRecordB;
  offset: Integer;
begin
  offset := PByte(@a.y) - PByte(@a);
  Writeln(SizeOf(a));
  Writeln(offset);
  offset := PByte(@b.y) - PByte(@b);
  Writeln(SizeOf(b));
  Writeln(offset);

this will output:
12
4
16
8

–jeroen

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

References for “The Future of Programming” a 2013 DBX conference talk still very relevant

Posted by jpluimers on 2020/09/24

At [WayBack] References for “The Future of Programming” you find the links and quotes Bret Victor used for his great talk.

The talk reminds me talks by Kevlin Henney, which combine a historic perspective on software development with how to apply that knowledge.

Time to dig into some more talks by Bret Victor and his site [WayBack] Bret Victor, beast of burden

He has done a lot of things, including designing the great resistor decoder I mentioned at Source: Electronics components and resistor decoder colours.

–jeroen

via: [WayBack] Jonas Bandi on Twitter: “It is easy to adopt new technologies, it can be hard to adopt new ways of thinking. https://t.co/gwbDrpWido”

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

Simple query to get .NET connection string from current SSMS connection – via: Database Administrators Stack Exchange

Posted by jpluimers on 2020/09/24

I’m connected to database. I use db by Management Studio 2012 Express. Can I check connection string by click something in Management Studio?

[WayBack] sql – How to check connection string in SSMS2012? – Database Administrators Stack Exchange

I adopted the SQL statement in the answer to the above question to:

  • use more common parameter names and values
  • embed strings in quotes
select
    -- part names via https://wiert.me/2012/11/07/netc-sqlclient-connectionstring-keys/
    -- prefer SSPI over True via https://wiert.me/2010/10/19/solution-for-ole-db-provider-connecting-to-sql-server-giving-error-multiple-step-ole-db-operation-generated-errors-check-each-ole-db-status-value-if-available-no-work-was-done/
    'Data Source=''' + @@servername + '''' +
    ';Initial Catalog=''' + db_name() + '''' +
    case type_desc
        when 'WINDOWS_LOGIN' 
        then ';Integrated Security=SSPI'
        else ';User ID=''' + suser_name() + ''';Password='''''
    end 
    as DotNetConnectionString,
    -- note the below need to be URI-encoded later on:
    'sqlserver://' + suser_name() + ':password@' + @@servername + '/' + db_name() + '?param1=value&param2=value'
    as GoLangConnectionString
    -- sqlserver://username:password@host/instance?param1=value&param2=value
    -- https://github.com/denisenkom/go-mssqldb#connection-parameters-and-dsn
from sys.server_principals
where name = suser_name()

You can use this to generate connection strings for use in .NET, OLE DB, Visual Studio Code, go lang and likely many other tools.

Related:

–jeroen

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Posted in Database Development, Development, Software Development, SQL, SQL Server, SSMS SQL Server Management Studio | Leave a Comment »

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