AW: O$ - why not use #F

[Rudolf Bargholz]

Hi Martin,

As Mike mentions indirectly, there are workarounds to some of the pitfalls when using global state, but you really should only use global state if there is no other option, or if there is a really, really good reason.

You can use reversible blocks, or use critical blocks, or use 

If sys(90)=1
 The do some stuff in the timer that might affect the flag #F
End If

in a $timer method to prevent the timer from changing the flag while other code is running, but long term it is a lot easier avoiding problems than it is trying to debug them. The use of variables of the smallest scope is just one tool to help in this regard.

I, for example, still use the old "For each line in list" for code that needs really fast loop processing in Studio, and this uses a "current list", which can be messed up by other methods setting their own "current list". You just have to be aware of possible pitfalls in these cases and code appropriately.

Regards

Rudolf Bargholz

-----Ursprüngliche Nachricht-----
Von: omnisdev-en <omnisdev-en-bounces at lists.omnis-dev.com> Im Auftrag von Martin Obongita via omnisdev-en
Gesendet: Dienstag, 26. Juli 2022 13:38
An: OmnisDev List - English <omnisdev-en at lists.omnis-dev.com>; Phil (OmnisList) <phil at pgpotter.co.uk>
Cc: Martin Obongita <martin.obongita at yahoo.com>
Betreff: Re: O$ - why not use #F

Thank you Phil and Rudolf.Does this phenomenon of unpredictability also apply to other global variables such as #1,#2, #L1, #L2 as used in a For loop: For #1 from 1 to #LN step 1 ?
Kind regards,Martin O.

Sent from Yahoo Mail on Android 
 
  On Tue, 26 Jul 2022 at 12:46, Phil (OmnisList)<phil at pgpotter.co.uk> wrote:   Martin,

Most developers will of moved away from relying on #F, mainly due to things like timers, which may pop in and do something when you least expect it, and maybe change the #F flag unexpectedly.

So using your own variable to hold any flag or status is a much safer way to go.

--
regards
Phil Potter
Based in Chester in the UK.
On 26/07/2022 09:57, Martin Obongita via omnisdev-en wrote:
>  Hi Paul,
> Sorry, I don't wish to be rude, but could I interject and ask why you use vbOK variable instead of using the inbuild #F variable to return the status of a flag?
> Kind regards, Martin.
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