mymatch Subroutine

subroutine mymatch(expression,string,expected)
use, intrinsic :: iso_fortran_env, only : ERROR_UNIT
use M_framework__verify, only: unit_check, unit_check_good, unit_check_bad, unit_check_done, unit_check_start, unit_check_level
character(len=*),intent(in) :: expression
character(len=*),intent(in) :: string
logical,intent(in)          :: expected
   type(regex_type)             :: regex
   integer,parameter            :: maxmatch=10
   integer                      :: matches(2,maxmatch)
   logical                      :: match
   integer                      :: istat
   integer                      :: i
   call regcomp(regex,expression,'x',status=istat)
   match=.false.
   if(istat/=0) then
      if(unit_check_level.gt.0)then
         write(ERROR_UNIT,'("runtime error in regcomp(3f):",a,", expression=",a)') regerror(regex,istat),expression
      endif
   else
      match=regexec(regex,string,matches,status=istat)
      if(istat/=0) then
         if(unit_check_level.gt.0)then
            write(ERROR_UNIT,'("runtime error in regexec:(3f)",a)') regerror(regex,istat)
         endif
      else if(match)then
         do i=1,maxmatch
            if(matches(1,i).le.0)exit
            if(unit_check_level.gt.0)then
               write(*,*) 'match="',regmatch(i,string,matches),'"'
            endif
         enddo
      endif
   endif
   call regfree(regex)
   call unit_check('M_regex',match .eqv. expected,msg='for REGEX '//trim(expression)//' and string '//trim(string))
end subroutine mymatch