Previously in bash & sed, in case anyone else was curious.
The total functional component was previously 25 lines long. Personally I would consider this different enough to be an entirely different project, but I guess this is a good way for the developer to avoid being asked to maintain something they're not interested in.
Well, previous approach was a dead end in terms of functionality and platform support.
I'd like to think of it as a prototype.
BTW, the test suit was written in Python and had been left in touch to ensure the same behavior if the rework.