println("Which directory do you want to scan?")
dir = read_line()
println("How deep should I search?")
depth = while {
    depth = read_line().parse_int()
    switch! depth {
        [] {
            println("depth wasn't an integer!")
            []
        }
        int if depth.gtoe(0) {
            // break from loop with value depth
            [depth]
        } else {
            // depth < 0
            println("depth was negative!")
            []
        }
    }
}

"Searching in {0} with a maximum depth of {1}...".format(dir depth).println()

fn find_all_files(dir string max_depth int) {
    files = ["" ...]
    &files.pop()
    entries = dir.fs_list()
    depth = 0
    while {
        new = ["" ...] // set type string
        &new.pop()
        for entry entries {
            local_entries = entry.fs_list()
            switch! local_entries {
                [] &files.push(entry)
                [string] for entry entry.fs_list() {
                    &new.push(entry)
                }
            }
        }
        entries = new
        depth = depth.add(1)
        if depth.gt(max_depth) [files] else []
    }
}

all_files = find_all_files(dir depth)
for file all_files file.println()