6. The method of claim 2 , wherein the second preset rule includes: returning a third preset identifier when the first character string is not empty, the first character string is composed of non-empty characters, and the to-be-collected character string is an empty character string, or the first character of the to-be-collected character string is an empty character.
2. The method of claim 1 , wherein the first preset rule includes: returning a corresponding result and using the corresponding result as a first partial regular expression when the first character string satisfies a second preset rule.