STLVecInt.f90

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module stlvecintmodule
  use kindmodule, only: i4b, lgp
  use simmodule, only: ustop
  use arrayhandlersmodule, only: expandarray
  implicit none
  private
  public :: stlvecint
 
  integer(I4B), parameter :: defaultinitialcapacity = 4
 
  ! This is a dynamic vector type for integers
  type :: stlvecint
    integer(I4B), private, allocatable :: values(:) !< the internal array for storage
    integer(I4B) :: size !< the number of elements (technically this stuff should be unsigned)
    integer(I4B) :: capacity !< the reserved storage
  contains
    procedure, pass(this) :: init !< allocate memory, init size and capacity
    procedure, pass(this) :: push_back !< adds an element at the end of the vector
    procedure, pass(this) :: push_back_unique !< adds an element at the end of the vector, if not present yet
    procedure, pass(this) :: add_array !< adds elements of array at the end of the vector
    procedure, pass(this) :: add_array_unique !< adds elements of array at the end of the vector, if not present yet
    procedure, pass(this) :: at !< random access, unsafe, no bounds checking
    procedure, pass(this) :: at_safe !< random access with bounds checking
    procedure, pass(this) :: set !< set value at index, no bounds checking
    procedure, pass(this) :: clear !< empties the vector, leaves memory unchanged
    procedure, pass(this) :: shrink_to_fit !< reduces the allocated memory to fit the actual vector size
    procedure, pass(this) :: destroy !< deletes the memory
    procedure, pass(this) :: contains !< true when element already present
    procedure, pass(this) :: get_index !< return index of first occurrence of value in array, -1 when not present
    procedure, pass(this) :: get_values !< returns a copy of the values
    ! private
    procedure, private, pass(this) :: expand
  end type stlvecint
 
contains ! module routines
 
  subroutine init(this, capacity)
    class(stlvecint), intent(inout) :: this
    integer(I4B), intent(in), optional :: capacity ! the initial capacity, when given
 
    if (present(capacity)) then
      this%capacity = capacity
    else
      this%capacity = defaultinitialcapacity
    end if
 
    allocate (this%values(this%capacity))
    this%size = 0
 
  end subroutine init
 
  subroutine push_back(this, newValue)
    class(stlvecint), intent(inout) :: this
    integer(I4B) :: newValue
    ! check capacity
    if (this%size + 1 > this%capacity) then
      call this%expand()
    end if
 
    this%size = this%size + 1
    this%values(this%size) = newvalue
 
  end subroutine push_back
 
  subroutine push_back_unique(this, newValue)
    class(stlvecint), intent(inout) :: this
    integer(I4B) :: newValue
 
    if (.not. this%contains(newvalue)) then
      call this%push_back(newvalue)
    end if
 
  end subroutine push_back_unique
 
  subroutine add_array(this, array)
    class(stlvecint), intent(inout) :: this
    integer(I4B), dimension(:), pointer :: array
    ! local
    integer(I4B) :: i
 
    do i = 1, size(array)
      call this%push_back(array(i))
    end do
 
  end subroutine add_array
 
  subroutine add_array_unique(this, array)
    class(stlvecint), intent(inout) :: this
    integer(I4B), dimension(:), pointer :: array
    ! local
    integer(I4B) :: i
 
    do i = 1, size(array)
      if (.not. this%contains(array(i))) then
        call this%push_back(array(i))
      end if
    end do
 
  end subroutine add_array_unique
 
  function at(this, idx) result(value)
    class(stlvecint), intent(in) :: this
    integer(I4B), intent(in) :: idx
    integer(I4B) :: value
 
    value = this%values(idx)
 
  end function at
 
  function at_safe(this, idx) result(value)
    class(stlvecint), intent(inout) :: this
    integer(I4B), intent(in) :: idx
    integer(I4B) :: value
 
    if (idx > this%size) then
      write (*, *) 'STLVecInt exception: access out of bounds, index ', idx, &
        ' exceeds actual size (', this%size, ')'
      call ustop()
    end if
    value = this%at(idx)
 
  end function at_safe
 
  subroutine set(this, idx, value)
    class(stlvecint), intent(inout) :: this
    integer(I4B), intent(in) :: idx
    integer(I4B) :: value
 
    this%values(idx) = value
 
  end subroutine set
 
  subroutine clear(this)
    class(stlvecint), intent(inout) :: this
 
    ! really, this is all there is to it...
    this%size = 0
 
  end subroutine clear
 
  subroutine shrink_to_fit(this)
    class(stlvecint), intent(inout) :: this
    ! local
    integer(I4B), allocatable :: tempValues(:)
    integer(I4B) :: i, newSize
 
    if (this%size == this%capacity) then
      return
    end if
 
    ! store temp
    newsize = this%size
    allocate (tempvalues(newsize))
    do i = 1, newsize
      tempvalues(i) = this%values(i)
    end do
 
    ! reinit
    call this%destroy()
    call this%init(newsize)
 
    ! copy back
    do i = 1, newsize
      call this%push_back(tempvalues(i))
    end do
 
  end subroutine shrink_to_fit
 
  subroutine destroy(this)
    class(stlvecint), intent(inout) :: this
 
    if (allocated(this%values)) then
      deallocate (this%values)
      this%size = 0
      this%capacity = 0
    else
      write (*, *) 'STLVecInt exception: cannot delete an unallocated array'
      call ustop()
    end if
 
  end subroutine destroy
 
  ! expand the array with the given strategy, at
  ! least by 1
  subroutine expand(this)
    class(stlvecint), intent(inout) :: this
    integer(I4B) :: increment
 
    ! expansion strategy
    increment = this%capacity / 2 + 1
    call expandarray(this%values, increment)
    this%capacity = this%capacity + increment
 
  end subroutine expand
 
  ! check if the element is already present
  function contains(this, val) result(res)
    class(stlvecint), intent(inout) :: this
    integer(I4B) :: val
    logical(LGP) :: res
    ! local
    integer(I4B) :: i
 
    res = .false.
    do i = 1, this%size
      if (this%at(i) == val) then
        res = .true.
        return
      end if
    end do
 
  end function contains
 
  !> @brief Return index of first occurrence,
  !< returns -1 when not present
  function get_index(this, val) result(idx)
    class(stlvecint), intent(inout) :: this
    integer(I4B) :: val
    integer(I4B) :: idx
    ! local
    integer(I4B) :: i
 
    idx = -1
    do i = 1, this%size
      if (this%at(i) == val) then
        idx = i
        return
      end if
    end do
 
  end function get_index
 
  function get_values(this) result(values)
    class(stlvecint), intent(in) :: this
    integer(I4B), dimension(:), allocatable :: values
 
    values = this%values(1:this%size)
 
  end function get_values
 
end module stlvecintmodule