subroutineparse_comprehensionrecursiveprivate

recursive subroutine parse_comprehension(c, s, element, id)
    type(fypp_t), intent(inout) :: c    !! the state
    type(scan_t), intent(inout) :: s    !! the expression
    integer, intent(in) :: element      !! the item
    integer, intent(out) :: id          !! the result
    integer :: clause, iterable, condition, name, comprehension

    comprehension = new_expr(c, E_COMP, element)
    do while (at_word(s, 'for') .and. .not. allocated(c%error))
        call next_token(c, s)
        clause = new_expr(c, E_CLAUSE)
        allocate (c%exprs(clause)%args(0), c%exprs(clause)%names(0))
        do
            if (s%kind /= T_NAME) call fail(c, 'cannot read the loop in: '//s%text)
            if (allocated(c%error)) return
            call intern(c, s%word, name)
            call push_id(c%exprs(clause)%names, name)
            call next_token(c, s)
            if (.not. at_word(s, ',')) exit
            call next_token(c, s)
        end do
        call expect(c, s, 'in')
        call parse_or(c, s, iterable)
        c%exprs(clause)%a = iterable
        do while (at_word(s, 'if'))
            call next_token(c, s)
            call parse_or(c, s, condition)
            call push_id(c%exprs(clause)%args, condition)
        end do
        call push_id(c%exprs(comprehension)%args, clause)
    end do
    id = comprehension
end subroutine parse_comprehension