I have recently seen 「やってもた」 used in a Japanese conversation, I don't remember the context exactly, but it was something like:
久々にやってもた。
After asking my Japanese friend, it turns out to be some kind of Osaka-ben expression used instead of 「やってしまった」, where the 「も」 stands for 「しまう」. My friend couldn't give me another use of this so I'm here asking two questions:
Is my explanation of 「やってもた」 accurate?
Can we extract from this example a generic grammatical rule that can be applied to most situation?
I seek to learn Osaka-ben and I'm trying to replace my old habits, so I would be very grateful if you can provide some external resources about this or at least mention your sources.