Re: [F-Script-talk] Questions and comments

[Philippe M. <pm...@ac...>]

Thanks for your comments and your questions. Better than the spam we 
got recently on this list!

> Okay, if no one else is asking, I have a couple of questions to put 
> out there (instead of spam).
>
> I'm playing with F-script nearly all the time. It's great fun...very 
> educational.
>
> But I do have these questions:
>
> 1) How do you remove an object (completely) from the sys workspace? 
> I've tried releasing them, but no. If I add NSWindow objects to the 
> workspace, I can't do saveSpace because NSWindows can't be archived 
> (freeze-dried), the error tells me.
>

An object is in the workspace if it is referenced by an F-Script 
variable or if it is referenced by an object which is in the workspace. 
This is why the workspace is usually a whole, complex, object graph.

To remove an object from the workspace you have to make sure that it is 
neither referenced by an F-Script variables, nor by an object that is 
itself part of the workspace.

For instance:

 > myWindow := NSWindow alloc initWithContentRect:(125<>513 
extent:400<>200)
                       styleMask:NSTitledWindowMask
                       backing:NSBackingStoreBuffered
                       defer:NO.

 > array := {1, 2, 3, myWindow}

After executing these two instructions, I have two more variables in my 
workspace: myWindow and myArray.

To remove the window from the workspace I have to make sure that it is 
no more referenced by the "myWindow" variable, and no more referenced 
by the array (because the array is itself part of the workspace). To do 
that I might execute:

 > myWindow := nil

and

 > array removeObjectAtIndex:3

> 2) How do you display a sheet (say, an alert) in a window. I keep 
> getting:
>
> error: argument 3 of method 
> beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:
> must be a compact Block
>
> What is a compact block? And why must it be there?
>

A compact block is something of the form:

#mySelector

It is the way to represents selectors in F-Script. In Objective-C, you 
would use @selector(mySelector) to denote the same selector.

Compact blocks are automatically mapped to Objective-C selectors when 
passed as arguments to methods.

Objective-C has both object types and non-object types. For instance, 
in Objective-C, selectors are not objects. In F-Script, everything is 
an object. This is why we need to define this kind of mapping between 
Objective-C non-object types and F-Script objects.

Note that compact block are named like this because they are instances 
of the Block class, and thus can be manipulated like regular blocks.

> And these comments:
>
> It's frustrating not to be able to use Cocoa convenience methods like 
> NSMakeRect and NSMakePoint. The end experience is that drawing becomes 
> a lot different from Cocoa (probably more like Smalltalk.)

The problem here is that F-Script let you invoke Objective-C methods, 
but not functions like NSMakeRect etc. This is not a design decision, 
but a current limitation of F-Script.

BTW, you're right, the F-Script way of dealing with points and 
rectangles is more Smalltalk-like.

> It's frustrating that the journaling/log of a F-Script session isn't 
> saved between sessions. What's the point?

I suppose you refer to the fact that the journal is reset when a new 
session begins.

Well, I used the journal a lot, when developing the first versions of  
F-Script, as a way to record what I was doing in order to have that 
information when F-Script crashed. But your idea to keep the old 
records is interesting.

Best,

Philippe Mougin

> I sure could use some examples of how to work with NSMatrix or NSCells 
> using F-Script's matrix orientation.
>
> Thanks for any enlightenment...
>
> --jcburns