I had a project where I had to translate a frequently updated Excel workbook containing lots of complicated formulas into a PHP project. So I parsed each cell and transpiled the Excel stuff into PHP, and the ran the resulting code.

The reason was Excel’s lack of an API. The formulas themselves were too complicated for existing solutions, and kept breaking them. I only built what was necessary so it worked out quicker.

No idea if that’s the same as the original use case, but it this kind of library looks like it does the same kind of thing on a more general level.