[lignuist]

I was referencing to "What if the character separating fields is not a comma?".

And there it clearly works. I used this technique a few times with success. If you find a CSV file that has mixed field separator types, then you probably found a broken CSV file.

[zAy0LfpBZLC8mAC]

No, it doesn't. What if there is #COMMA# in one of the fields?

[lignuist]

You just choose a placeholder that does not appear in the data. You could even implement it in a way that a placeholder is automatically selected upfront that does not appear in the data.

When it comes to parsing, the thing is that you usually have to make some assumptions about the document structure.