demo_M_list.f90 Source File

     program demo_M_list
     use M_list, only : insert, locate, replace, remove
     ! create a dictionary with character keywords, values, and value lengths
     ! using the routines for maintaining a list

      use M_list, only : locate, insert, replace
      implicit none
      character(len=:),allocatable   :: keywords(:)
      character(len=:),allocatable   :: values(:)
      integer,allocatable            :: counts(:)
      integer                        :: i
      ! insert and replace entries
      call update('b','value of b')
      call update('a','value of a')
      call update('c','value of c')
      call update('c','value of c again')
      call update('d','value of d')
      call update('a','value of a again')
      ! show array
      write(*,'(*(a,"==>","[",a,"]",/))')&
       & (trim(keywords(i)),values(i)(:counts(i)),i=1,size(keywords))
      ! remove some entries
      call update('a')
      call update('c')
      write(*,'(*(a,"==>","[",a,"]",/))')&
       & (trim(keywords(i)),values(i)(:counts(i)),i=1,size(keywords))
      ! get some values
      write(*,*)'get b=>',get('b')
      write(*,*)'get d=>',get('d')
      write(*,*)'get notthere=>',get('notthere')
      !
      contains
      subroutine update(key,valin)
      character(len=*),intent(in)           :: key
      character(len=*),intent(in),optional  :: valin
      integer                               :: place
      integer                               :: ilen
      character(len=:),allocatable          :: val
      if(present(valin))then
         val=valin
         ilen=len_trim(val)
         ! find where string is or should be
         call locate(keywords,key,place)
         ! if string was not found insert it
         if(place.lt.1)then
            call insert(keywords,key,iabs(place))
            call insert(values,val,iabs(place))
            call insert(counts,ilen,iabs(place))
         else
            call replace(values,val,place)
            call replace(counts,ilen,place)
         endif
      else
         call locate(keywords,key,place)
         if(place.gt.0)then
            call remove(keywords,place)
            call remove(values,place)
            call remove(counts,place)
         endif
      endif
      end subroutine update
      function get(key) result(valout)
      character(len=*),intent(in)   :: key
      character(len=:),allocatable  :: valout
      integer                       :: place
         ! find where string is or should be
         call locate(keywords,key,place)
         if(place.lt.1)then
            valout=''
         else
            valout=values(place)(:counts(place))
         endif
      end function get
      end program demo_M_list