Challenge: A Self-Replicating App

[William Lancee]

@Erel's Quizzes always generate a lot of interest. In this crisis of viral replication, I remembered a challenge from when I taught programming to Engineering students.

Without using the file system or the clipboard, write a minimal program that displays itself.

#Region Project Attributes
    #MainFormWidth: 600
    #MainFormHeight: 600
#End Region
Sub Process_Globals
    Private fx As JFX
    Public MainForm As Form
End Sub
Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    Dim textArea1 As TextArea: textArea1.Initialize("")
    MainForm.RootPane.AddNode(textArea1, 0, 0, MainForm.Width, MainForm.Height)
    MainForm.Title = "This is an exact replica of myself!"
    MainForm.Show
    'textArea1.Text =  ??              'In how many lines can you do this?   My best shot is 66 lines, including this preamble.
End Sub

 

[Erel]

I'm not sure that I understand the challenge...

 

[LucaMs]

I'm not sure that I understand the challenge...

I am instead sure that... I don't understand it ?

 

[OliverA]

I’m guessing that you should fill the textarea field in such a way that the content is a screen copy of the app.

 

[Erel]

But TextArea only shows text

 

[ilan]

i think you he wants to put the whole source code of a project in the textarea inside.
but it does not make any sense so maybe i am wrong

 

[LucaMs]

But TextArea only shows text

TextArea1.Text = MainForm.Title ?

 

[LucaMs]

The real quiz is guessing the meaning of the quiz.
It must be a recursion problem.

 

[sorex]

write a minimal program that displays itself.

#Region Project Attributes
    #MainFormWidth: 600
    #MainFormHeight: 600
#End Region
Sub Process_Globals
    Private fx As JFX
    Public MainForm As Form
End Sub
Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    Dim textArea1 As TextArea: textArea1.Initialize("")
    MainForm.RootPane.AddNode(textArea1, 0, 0, MainForm.Width, MainForm.Height)
    MainForm.Title = "This is an exact replica of myself!"
    MainForm.Show
    textArea1.Text = "itself."
End Sub

 

[Sandman]

I'm not sure that I understand the challenge

I believe the topic is unfortunate and make it slightly confusing. I'd venture a guess that the challenge is to create an app that displays its own source.

 

[udg]

Here you are..more or less.
It could be better and go to 100% accuracy, but it was just an exercise to prove itc ould be easily done.
Thanks for the challenge, it was a nice pastime for my afterlunch.

 

[LucaMs]

Here you are..more or less.
It could be better and go to 100% accuracy, but it was just an exercise to prove itc ould be easily done.
Thanks for the challenge, it was a nice pastime for my afterlunch.

I'm pretty sure that it's not what @William Lancee means:

My best shot is 66 lines, including this preamble.

If, on the other hand, that is exactly what he meant... it is a big nonsense!

 

[Erel]

I think that @udg is write. Nice one.

 

[LucaMs]

I think that @udg is write. Nice one.

I really hope not ?
?

 

[LucaMs]

I think that @udg is write. Nice one.

It certainly isn't what he means, otherwise @William Lancee wouldn't have had to write 66 lines of code!


Whoever knows his phone number, call him, we can't wait any longer ?

 

[josejad]

My best shot is 66 lines, including this preamble.

Maybe is something like Fermat's last theorem?

Fermat added that he had a proof that was too large to fit in the margin

 

[Erel]

It certainly isn't what he means, otherwise @William Lancee wouldn't have had to write 66 lines of code!

I think that you missed something It is not so simple. Try it.

 

[LucaMs]

I think that you missed something It is not so simple. Try it.

Likely; obviously if that was really the meaning of the quiz, when William arrives, I will certainly shoot him!
?

 

[William Lancee]

1. @udg is certainly almost right, but has some bugs. And some of those bugs not so easy to fix.
2. @LucaMs, it is much harder than it looks. @udg's method is not the only one. For example why don't you try it with smart strings.
3. I did not say my solution is the best. But it is funny to run the App from its copy and get another copy!

 

[LucaMs]

@udg's method is not the only one. For example why don't you try it with smart strings.

He used them (also)