functionlexical_cleanprivate

function lexical_clean(path) result(out)
    character(len=*), intent(in) :: path    !! the path
    character(len=:), allocatable :: out
    type(string_t), allocatable :: parts(:), kept(:)
    integer :: k, n, first

    first = merge(3, 1, has_drive(path))
    parts = split_on(path(first:), '/')
    allocate (kept(size(parts)))
    n = 0
    do k = 1, size(parts)
        if (parts(k)%s == '' .or. parts(k)%s == '.') cycle
        if (parts(k)%s == '..') then
            n = max(0, n - 1)
            cycle
        end if
        n = n + 1
        kept(n)%s = parts(k)%s
    end do
    out = path(:first - 1)//'/'//join(kept(1:n), '/')
end function lexical_clean