In Rust regex, is there a similar function to filtered_re.h in RE2

[yangwentong]

In RE2, filtered_re.h provides a prefilter mechanism that helps in cutting down the number of regexps that need to be actually searched.
Like:

// filtered_re.h

  // Prepares the regexps added by Add for filtering.  Returns a set
  // of strings that the caller should check for in candidate texts.
  // The returned strings are lowercased and distinct. When doing
  // string matching, it should be performed in a case-insensitive
  // way or the search text should be lowercased first.  Call after
  // all Add calls are done.
  void Compile(std::vector<std::string>* strings_to_match);

I would like to ask if there is a function similar to Compile in Rust regex, or other functions provided in filtered_re.h?

[BurntSushi]

No. You can use the regex-syntax to look at the HIR and extract substrings yourself though if you want. And the regex crate does that internally and tries to do at least part of the filtered_re.h optimization on its own, automatically.

[yangwentong]

Thank you for answering my questions