[Help-bash] Implement a key-value deserialization or something similar

[Sebastian Gniazdowski]

I'm wondering how to best implement a parameter $x, say $7 – I mean a
last parameter to a parameter-rich function – that would serve as "put
various key-data things here to stop adding more parameters"? Possible
call could be: afunction param1 param2 ... "MYDATA=1 OTHERDATA=true".
It's that I need to pass bunch of simple marks on some data to a
function and don't need reserved positional parameters for them.

Best regards,
Sebastian Gniazdowski