FWEB

@* Factorial in FWEB.

This program computes the factorial of an integer using
the FWEB literate programming system for Fortran.

@f
      program factorial
      implicit none
      integer :: n, i, result
      n = 5
      @<Compute factorial of n@>
      write(*,'(a,i0)') 'Factorial of 5 = ', result
      end program

@ The factorial is computed by multiplying integers from 1 to n.
@<Compute factorial of n@>=
      result = 1
      do i = 1, n
        result = result * i
      end do