Directory separator is '/'.
dir.split_name("\\server\share\foo", "\\server\share", "foo").
"\\server\share"/"foo" = "\\server\share/foo".
dir.dirname("\\server\share\foo") = "\\server\share".
dir.basename("\\server\share\foo") = "foo".
dir.path_name_is_absolute("\\server\share\foo").
dir.path_name_is_root_directory("\\server\share\foo") failed

dir.split_name("\\server\share", _, _) failed.
dir.dirname("\\server\share") = "\\server\share".
dir.basename("\\server\share") = _ failed.
dir.path_name_is_absolute("\\server\share").
dir.path_name_is_root_directory("\\server\share").

dir.split_name("\\server\share\\", _, _) failed.
dir.dirname("\\server\share\\") = "\\server\share\".
dir.basename("\\server\share\\") = _ failed.
dir.path_name_is_absolute("\\server\share\\").
dir.path_name_is_root_directory("\\server\share\\").

dir.split_name("C:\foo", "C:\", "foo").
"C:\"/"foo" = "C:\foo".
dir.dirname("C:\foo") = "C:\".
dir.basename("C:\foo") = "foo".
dir.path_name_is_absolute("C:\foo").
dir.path_name_is_root_directory("C:\foo") failed

dir.split_name("C:\foo\", "C:\", "foo").
"C:\"/"foo" = "C:\foo".
dir.dirname("C:\foo\") = "C:\".
dir.basename("C:\foo\") = "foo".
dir.path_name_is_absolute("C:\foo\").
dir.path_name_is_root_directory("C:\foo\") failed

dir.split_name("C:\", _, _) failed.
dir.dirname("C:\") = "C:\".
dir.basename("C:\") = _ failed.
dir.path_name_is_absolute("C:\").
dir.path_name_is_root_directory("C:\").

dir.split_name("C:", _, _) failed.
dir.dirname("C:") = ".".
dir.basename("C:") = "C:".
dir.path_name_is_absolute("C:") failed
dir.path_name_is_root_directory("C:") failed

dir.split_name("\", _, _) failed.
dir.dirname("\") = "\".
dir.basename("\") = _ failed.
dir.path_name_is_absolute("\").
dir.path_name_is_root_directory("\").

dir.split_name("", _, _) failed.
dir.dirname("") = ".".
dir.basename("") = "".
dir.path_name_is_absolute("") failed
dir.path_name_is_root_directory("") failed

dir.split_name("foo\\bar\", "foo", "bar").
"foo"/"bar" = "foo/bar".
dir.dirname("foo\\bar\") = "foo".
dir.basename("foo\\bar\") = "bar".
dir.path_name_is_absolute("foo\\bar\") failed
dir.path_name_is_root_directory("foo\\bar\") failed

dir.split_name("foo\bar\", "foo", "bar").
"foo"/"bar" = "foo/bar".
dir.dirname("foo\bar\") = "foo".
dir.basename("foo\bar\") = "bar".
dir.path_name_is_absolute("foo\bar\") failed
dir.path_name_is_root_directory("foo\bar\") failed

dir.split_name("foo", _, _) failed.
dir.dirname("foo") = ".".
dir.basename("foo") = "foo".
dir.path_name_is_absolute("foo") failed
dir.path_name_is_root_directory("foo") failed

dir.split_name("/foo", "/", "foo").
"/"/"foo" = "/foo".
dir.dirname("/foo") = "/".
dir.basename("/foo") = "foo".
dir.path_name_is_absolute("/foo").
dir.path_name_is_root_directory("/foo") failed

dir.split_name("/foo//bar///", "/foo", "bar").
"/foo"/"bar" = "/foo/bar".
dir.dirname("/foo//bar///") = "/foo".
dir.basename("/foo//bar///") = "bar".
dir.path_name_is_absolute("/foo//bar///").
dir.path_name_is_root_directory("/foo//bar///") failed

dir.split_name("//foo//bar/", _, _) failed.
dir.dirname("//foo//bar/") = "//foo/bar/".
dir.basename("//foo//bar/") = _ failed.
dir.path_name_is_absolute("//foo//bar/").
dir.path_name_is_root_directory("//foo//bar/").

dir.split_name("//foo//", _, _) failed.
dir.dirname("//foo//") = "//foo/".
dir.basename("//foo//") = _ failed.
dir.path_name_is_absolute("//foo//").
dir.path_name_is_root_directory("//foo//").

dir.split_name("/", _, _) failed.
dir.dirname("/") = "/".
dir.basename("/") = _ failed.
dir.path_name_is_absolute("/").
dir.path_name_is_root_directory("/").

dir.split_name("//", _, _) failed.
dir.dirname("//") = "/".
dir.basename("//") = _ failed.
dir.path_name_is_absolute("//").
dir.path_name_is_root_directory("//").

dir.split_name("foo/bar", "foo", "bar").
"foo"/"bar" = "foo/bar".
dir.dirname("foo/bar") = "foo".
dir.basename("foo/bar") = "bar".
dir.path_name_is_absolute("foo/bar") failed
dir.path_name_is_root_directory("foo/bar") failed

"C:"/"foo" = "C:/foo".
"C:\"/"foo" = "C:\foo".
"C:"/"C:" = "C:/C:".
"C:"/"C:\foo" threw exception: software_error("function `dir./\'/2: Unexpected: second argument is absolute")
"."/"/foo" threw exception: software_error("function `dir./\'/2: Unexpected: second argument is absolute")
"."/"\foo" threw exception: software_error("function `dir./\'/2: Unexpected: second argument is absolute")
"foo"/"bar/baz" = "foo/bar/baz".
"foo/"/"bar/baz" = "foo/bar/baz".
checking whether `unwritable' is readable...ok
unwritable file found to be unwritable
current_directory succeeded: hard_coded
make_directory succeeded
make_directory succeeded
dir.make_single_directory with non-existent parent failed as expected.
make_single_directory succeeded
make_single_directory 2 succeeded
file_type succeeded
type of test_dir/d1 is directory
file_type 2 succeeded
type of dir_test.m is regular_file
touching file succeeded
touching file succeeded
touching file succeeded
touching file succeeded
creating directory with same name as ordinary file failed (as expected).
making symlink 1 succeeded
making symlink 2 succeeded
making symlink 3 succeeded
following symlink succeeded
test_dir/d1/bar points to baz
file_type 3 succeeded
type of test_dir/d1/bar is symbolic_link
dir.foldl2 succeeded
Files in test_dir:
test_dir/d1, test_dir/d2, test_dir/d3, test_dir/quark, test_dir/queeg
dir.recursive_foldl2 (no symlinks) succeeded
Files in test_dir (recursive, not following symlinks):
test_dir/d1, test_dir/d1/bar, test_dir/d1/baz, test_dir/d1/foo, test_dir/d1/parent, test_dir/d2, test_dir/d2/d2, test_dir/d3, test_dir/quark, test_dir/queeg
dir.recursive_foldl2 (symlinks) succeeded
Files in test_dir (recursive, following symlinks:
test_dir/d1, test_dir/d1/bar, test_dir/d1/baz, test_dir/d1/foo, test_dir/d1/parent, test_dir/d2, test_dir/d2/d2, test_dir/d3, test_dir/d3/bar, test_dir/d3/baz, test_dir/d3/foo, test_dir/d3/parent, test_dir/quark, test_dir/queeg
dir.recursive_foldl2(list_files, "dir_test.m", ...) failed as expected.