If your regex is replaceable by a simple "find_substring" or equivalent, it's slow.
If your regex is complicated, it will probably beat any naive attempt to write it into conventional string processing, short of reimplementing regexs in the first place. Especially since in many languages, "conventional string processing" may involve the creation of lots of copies and sub-copies.
If your regex is complicated, it will probably beat any naive attempt to write it into conventional string processing, short of reimplementing regexs in the first place. Especially since in many languages, "conventional string processing" may involve the creation of lots of copies and sub-copies.