module Exceptions:sig..end
exception Regex_no_such_subpattern of int * int
Regex_no_such_subpattern (n, max) means n was requested but only max
      subpatterns are defined (so max - 1 is the highest valid index)
Regex_no_such_named_subpattern (name, pattern)
exception Regex_no_such_named_subpattern of string * string
Match_failed patternexception Regex_match_failed of string
Regex_submatch_did_not_capture (s, i) means the ith subpattern in the
      regex compiled from s did not capture a substring.exception Regex_submatch_did_not_capture of string * int
exception Regex_compile_failed of string
Regex_rewrite_template_invalid (template, error_msg)exception Regex_rewrite_template_invalid of string * string