import libc.*;



findFirstFile(path) {
    var dirp = opendir(cstring(path));
    if (null?(dirp)) throw 1;
    return dirp;
}
findNextFile(dirp) = FileSequence(dirp);
findClose(dirp) = closedir(dirp);



//
// FileSequence
//

private record FileSequence {
    d : Pointer[DIR];
}

overload iterator(x:FileSequence) =  FileIterator(x.d, false, null(Struct_dirent));



//
// FileIterator
//

private record FileIterator {
    dirp : Pointer[DIR];
    queued? : Bool;
    entry : Pointer[Struct_dirent];
}

overload hasNext?(x:FileIterator) {
    if (not x.queued?) {
        x.queued? = true;

        var returnCode = readdir_r(x.dirp, allocateMemory(Struct_dirent, 1), &x.entry);

        if (returnCode != 0)
            throw returnCode;
    }
    return not(null?(x.entry));
}

overload next(x:FileIterator) {
    if (not x.queued?)
         hasNext?(x);
    x.queued? = false;
    return x.entry;
}

// /////////////////////////////////////////////////////

main() {
    for (x in findNextFile(findFirstFile("/home")))
        puts(&x^.d_name[0]);
}