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'Storing' variables in RAM

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Daniel
Daniel on 7 May 2021
Commented: Daniel on 10 May 2021
Is there a way to store data without writing it to the drive?
Result should be that 'clear all' does not affect the variable/handle, but EEPROM doesn't constantly have to be written to. Similar to the Instrument Toolbox, where instruments are kept regardless of what happens in the workspace and are only removed with the 'delete'-command.
And yes, i know, 'Don't use clear all, it's resource intensive and almost never necessary'. Not an option.

Accepted Answer

Jan
Jan on 7 May 2021
Edited: Jan on 7 May 2021
Store the wanted data persistently:
function Out = DataVault(Cmd, Name, Data)
persistent Stored
mlock;
switch lower(Cmd)
case 'store'
Stored.(Name) = Data;
case 'get'
Out = Stored.(Name);
case 'clear'
Stored = [];
munlock;
otherwise
error('Jan:DataValut:BadCmd', 'Unknown command: [%s]', Cmd);
end
Now call it:
ValuableData = 4711;
DataVault('store', 'Box1', ValuableData);
clear all
ValuableData = DataValut('get', 'Box1')
Of course, clean code would simply omit all clear all calls, because they remove all (unlocked) functions from the memory. You say, that this is not an option. I resist on preferring trustworthy code, which does not contain junk.
If the clear all comes from evil subfunctions, you can either shadow the clear command by defining your own clear function, or if they are scripts, define a variable "all", such that "clear all" clears this variable only. Brrr.
  1 Comment
Daniel
Daniel on 10 May 2021
Evil, evil... Not keen on a coding war, so I'm probably going to let the 'define all as a variable'-approach pass, but if I implemented a clear function in my library that clears everything but what I want to keep, that might just work. Thanks for the advice!

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