问题
We have 2 versions of a text T before and after,
before:
a\nb\n
after:
b\n
define regex ^[^\n].*\n$ as Line,
define operation delete_line of deleting a substring that match Line from a text,
define operation add_line of adding a substring that match Line from a text,
Obviously, T can transform with operation delete_line.
is there a library that give a general solution of this problem?
Given a set of regex ,it will calculate if the text can transform before to after.
来源：https://stackoverflow.com/questions/54017344/transform-text-with-given-pattern