Archive for the ‘With statement’ Category
Posted by jpluimers on 2024/03/05
Last year, within a week, I saw two tweets of languages that, like Pascal, have a with statement as well:
- [Archive.is] Shawn Wildermuth 💻☕🎸🎥🎮 on Twitter: “JavaScript’s Forgotten Keyword (with)”
- [Archive.is] John Kaster #BlackLivesMatter on Twitter: “@suited_aces @marcocantu @delphijunkie @JimMcKeeth @jpluimers I present “with”… “
The first points to an article that shows the JavaScript implementation of with is very similar to the Pascal one: [Wayback] JavaScript’s Forgotten Keyword (with) – DEV Community.
Just in case some of my readers do not know my opinion of the Pascal with statement (it even has it’s own blog category), I really think you should not use it Delphi: you should avoid the with statement as it makes your code less future proof.
The reason not to use it is called [Wayback] Accidental Shadowing in computer language speak (it also can rear its head when you define variables at different block levels like for instance this golang example: [Wayback] Warning for accidental variable shadowing with block scope – Technical Discussion – Go Forum).
Even the JavaScript specification advises against using the with keyword in [Wayback] with – JavaScript | MDN
**Warning:**Use of the with statement is not recommended, as it may be the source of confusing bugs and compatibility issues. See the “Ambiguity Contra” paragraph in the “Description” section below for details.
There have been various proposals to extend the Delphi implementation of the with statement to make it more resilient to Accidental Shadowing by forcing the usage to be prepended by a . (dot) or alias, as for instance seen in [Wayback] Re: “with” Coders are Monsters – delphi / [Wayback] delphi • View topic • “with” Coders are Monsters:
This is in fact what the second twitter messages pointed to: a VB.NET example doing just that: prepend with a dot: [Wayback] Maarten Balliauw on Twitter: “Looks like using With makes it pretty clean!… “
I was not even aware that VB.NET had it, but it has: [Wayback] With…End With Statement – Visual Basic | Microsoft Docs
And it has similar debugging issues as with Delphi as per [Wayback] The VB.NET ‘With’ Statement – embrace or avoid? – Stack Overflow:
Find the beginning of a With statement and set a breakpoint. Step to the next line (so you’re hiding the first line right under the if block). Highlight it, then ‘Add Watch’. You should see this: ‘With’ contexts and statements are not valid in debug windows.
–jeroen
Posted in Delphi, .NET, Software Development, Development, Scripting, VB.NET, JavaScript/ECMAScript, Pascal, With statement, Go (golang) | Leave a Comment »
Posted by jpluimers on 2014/08/12
In the With Statement series:
Lars Fosdal – Code Rants
The dreaded with…
Debugging today, I found another gotcha.
In this case, both Self and DisconnectedClient has a property named ClientIdentifier.
Note the difference for the mouse-over and the evaluation.
–jeroen
Read the rest of this entry »
Posted in Appmethod, Borland Pascal, Delphi, Delphi 1, Delphi 2, 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, Delphi XE5, Delphi XE6, Delphi XE7, Development, Pascal, Software Development, Turbo Pascal, With statement | Leave a Comment »
Posted by jpluimers on 2014/06/11
A bit more than a year ago, I wrote about Delphi: you should avoid the with statement as it makes your code less future proof. That caused some nice comments on the blog, and some more on LinkedIn where Paul Foster mentioned it in a thread ‘Jeroen Pluimers makes a case against “with” statements.‘ Both interesting reads, especially the reasons that people use or avoid with, or keep its use in balance. There is one set of comments I want to emphasize: refactoring multiple with statements into a one function and a call per former with. Read the rest of this entry »
Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Development, Pascal, Software Development, Turbo Pascal, With statement | 19 Comments »
Posted by jpluimers on 2014/03/13
Yet another example of somehow who got bitten hard by using the with statement (I decided to give with its own category on my blog).
This time it got shared by Paul Foster on G+ and comes down to this:
Even in unsuspiciously looking code, the wit statement can bite you, especially if you need to do refactoring and (because of that) introduce two names in the same scope.
Or in Paul‘s words:
Whilst upgrading the code to remove the Containers unit (its not supported on NextGen platforms, so I have to make things work with Generics.Collections instead, (bye bye D7 support for this code) and refactor a couple stupidities in my original design (they always creep in, don’t they) I ended up with two class members of the same name. The with block then looked OK but I was in fact not access the member I thought I was.
–jeroen
via: Paul Foster – Google+ – WITH IS EVIL! God damn it, I know it makes code easier to….
Posted in Borland Pascal, Delphi, Delphi 1, Delphi 2, 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, Delphi XE5, Development, Pascal, Software Development, Turbo Pascal, With statement | 18 Comments »
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 »
The Wiert Corner - irregular stream of stuff 