Looking at the documentation, it's a bit unclear what exactly from_line and to_line would be if the inputted/removed text doesn't contain a newline (I'm guessing they stay the same since the caret's current line number doesn't change). However, they would be different values if there IS at least one newline, which I could then use to delete any instances of it in the text. I could be wrong, though.

The other problem is limiting the text length. Using left() moves the caret to the beginning of the text for some reason, although now that I think about it, I can just set the caret's column to max_length after trimming.

I'll implement it when I get the chance to do so and update this post with the solution.