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Bay Six Software
Beyond the Basics
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Brent
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Joined: 01 Jul 2005
Posts: 800
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 Posted: Feb 24th, 2012, 10:49am Post subject: Experiment - Simple windowed application |
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This is an attempt to translate a Rosetta Code task into what I think VF might look like.
| Code: | require stdwindows #windows
object #demo is window
title = "Rosetta Task: Simple windowed application"
button #btn, "Click Me", btnClick, 20, 50, 100, 25
statictext #num, "There have been no clicks yet.", 20, 100, 240, 30
sub btnClick #sender
static nClicks
nClicks += 1
#num "The button has been clicked ";nClicks;" times."
end sub
end object
#demo show()
do wait while #windows count?
end |
Require - a list of modules the program requires. The handle is optional and allows access to module-level methods.
Object - defines an object commonly called a Singleton. This is convenient when we don't need a full-blown class.
Is - indicates the parent from which a child class/object inherits some functionality.
Title - a method exposed by the Window class. The line could also be written title("Rosetta blah blah"). The equals sign can be used when a method has just one argument.
Button - a class exposed by StdWindows. The line it starts declares an object that is private to #demo. btnClick is the name of a subroutine. (I think no labeled event handlers for VF.) Unlike LB, UL and the like are optional. The button constructor literally takes a Rect object from which UL is derived. In VF, anywhere an object argument is expected, we can pass what that object's constructor expects instead. This may also allow for a flowing arrangement rather than pixel coordinates.
Sub - looks and works very much like LB. Subs and functions are private inside classes. If this were to use Method instead, that would be exposed.
Static - similar to LB's Global but the variable is local in scope to the sub. It lives as long as the object does.
+= - assigns the sum of the variable and the RHS expression to the same variable. Copied from C-like languages.
Show() - calls the method exposed by the Window class. Windows are hidden until explicitly shown.
Do - permits defining a very tight loop - one with just a single statement. The line waits for all windows to close. The question mark is an optional replacement for the empty parentheses.
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Brent |
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STPendl
Full Member
Joined: 20 Aug 2007
Posts: 161
Location: Austria
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| Posted: Feb 25th, 2012, 9:49am Post subject: Re: Experiment - Simple windowed application |
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I like the idea and the code is clean.
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Stefan
Any code I post can be freely used, just give credit. |
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nukesrus21
Junior Member
Joined: 19 Oct 2010
Posts: 13
Location: Southbury, CT
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| Posted: Apr 23rd, 2012, 10:20am Post subject: Re: Experiment - Simple windowed application |
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Brent,
I've been looking this stuff over. Pretty neat stuff!!
Just a thought here............
I am not sure how I would feel about this:
Maybe something like:
| Code: | protected nClicks
'or
local nClicks |
When I see the word "static" I just think of something that is unchanging.
{:0)
Brandon
EDIT: ..... What is all this garbage that is showing up down here? It doesn't show up in the preview. Looks like something from Stefan's post. ..... |
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Alyce
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Joined: 04 Jul 2005
Posts: 91
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| Posted: Apr 23rd, 2012, 10:49am Post subject: Re: Experiment - Simple windowed application |
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@Brandon, I don't have experience with too many languages, so I cannot speak with a lot of confidence, but...
In Visual Basic, a static variable (sounds like a contradiction in terms) is one that is local in scope, but retains its value even after a function returns. The next time the function is called, the value persists. It's not visible to the main program like a variable declared globally. To me, it seems like a way to include OOP features in a non-OOP language.
http://www.1sayfa.com/1024/diger/vb/ch07.htm#Heading12
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RichardRussell
Full Member
Joined: 28 Jan 2012
Posts: 57
Location: Downham Market, UK
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| Posted: Apr 23rd, 2012, 1:19pm Post subject: Re: Experiment - Simple windowed application |
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| nukesrus21 wrote: | Maybe something like:
| Code: | protected nClicks
'or
local nClicks |
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My personal preference is for:
I share your dislike of static. It originates from C, I think, in which it has multiple (and confusing IMHO) meanings. To me local doesn't imply that the value is preserved from one call to the next, which is the key feature.
Richard. |
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Brent
Site Admin
Joined: 01 Jul 2005
Posts: 800
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| Posted: Apr 23rd, 2012, 4:45pm Post subject: Re: Experiment - Simple windowed application |
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The "static" keyword may have originated with C, but my usage in the example derives from its use in QBasic. The following is valid QBasic. | Code: | SUB counter
STATIC c
c = c + 1
END SUB |
If you want to know more about the concept, try http://en.wikipedia.org/wiki/Static_variable.
The original example could be rewritten (including updated naming) as | Code: | require StdGUI #gui
object #demo is window
var nClicks ' private to the object
title = "Rosetta Task: Simple windowed application"
button #btn, "Click Me", btnClick, 20, 50, 100, 25
statictext #num, "There have been no clicks yet.", 20, 100, 240, 30
sub btnClick #sender
nClicks += 1
#num "The button has been clicked ";nClicks;" times."
end sub
end object
#demo show()
do wait while #gui WindowCount?
end |
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Brent |
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JosephE
Junior Member
Joined: 01 Nov 2007
Posts: 21
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| Posted: May 15th, 2012, 2:41am Post subject: Re: Experiment - Simple windowed application |
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| If this is how it ends up, this could quite possibly be the most wonderful programming language ever created. I'm going to start reading about this. |
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