anchor.diff:  !  NOTA BENE:
   !  - id, gen and weight are assigned by the fluka_mod_init subroutine;
   !  - z and zp are actually useless (but we never know);
  -!  - in case the file contains less particle than napx, napx is re-assigned
   !
   ! ================================================================================================ !
   module mod_dist
  
positive.code: 
    character(len=:), allocatable, private, save :: dist_partLine(:)    ! PARTICLE definitions in the block
    integer,                       private, save :: dist_nParticle = 0  ! Number of PARTICLE keywords in block
    
    integer,                       private, save :: dist_numPart   = 0  ! Number of actual particles generated or read
  
    !  Column formats
  
negative.code: ! ================================================================================================ !
  !
  !  Read a beam distribution
  ! ~~~~~~~~~~~~~~~~~~~~~~~~~~
  !
  !  A. Mereghetti and D. Sinuela Pastor, for the FLUKA Team
  !  V.K. Berglyd Olsen, BE-ABP-HSS
  !  Last modified: 2019-07-09
  !
  !  Format of the original DIST input file:
  !    id:         unique identifier of the particle (integer)
  !    gen:        parent ID (integer)
  !    weight:     statistical weight of the particle (double: >0.0)
  