read_activation Function

  function read_activation(unit, iline) result(activation)
    !! Read activation function from input file
    implicit none

    ! Arguments
    integer, intent(in) :: unit
    !! Unit number for input file
    integer, intent(inout), optional :: iline
    !! Line number

    class(base_actv_type), allocatable :: activation
    !! Activation function object

    ! Local variables
    type(onnx_attribute_type), allocatable, dimension(:) :: attributes
    !! Array of ONNX attributes
    integer :: i
    !! Loop variable
    character(20) :: actv_name
    !! Activation function name
    logical :: found
    !! Flag for finding activation creator
    integer :: creator_index
    !! Index of activation creator
    integer :: iline_ = 0
    !! Line number

    ! initialise list if needed
    if(.not.allocated(list_of_onnx_activation_creators)) &
         call allocate_list_of_onnx_activation_creators()

    ! Read activation attributes
    attributes = read_activation_attributes(unit, iline=iline_)
    if(present(iline)) iline = iline + iline_

    ! Extract activation name
    actv_name = ""
    do i=1, size(attributes,dim=1)
       if(trim(to_lower(attributes(i)%name)) .eq. "name")then
          actv_name = trim(to_lower(attributes(i)%val))
          exit
       end if
    end do
    if(actv_name .eq. "")then
       call stop_program( &
            "Activation name '"// actv_name //"' not specified in activation block" &
       )
       return
    end if
    do i = 1, size(list_of_onnx_activation_creators,dim=1)
       if(trim(to_lower(list_of_onnx_activation_creators(i)%name)) .eq. actv_name)then
          found = .true.
          creator_index = i
          exit
       end if
    end do
    if(.not.found)then
       call stop_program( &
            "Activation name '"// actv_name //"' not recognised" &
       )
       return
    end if
    allocate(activation, source = list_of_onnx_activation_creators(creator_index)% &
         create_ptr(attributes))

  end function read_activation