Again, I'm not sure I totally buy it, but it's an interesting idea.

Consider this (thoroughly untested) code:

sub add_stuff_to_file {
    my ($filehandle, $stuff) = @_;
    ($stuff->isa('Iterable')) || die "Stuff must be iterable";
    my $i = $stuff->iterator();
    ($i->isa('Iterator')) || die "Stuff's iterator must be an Iterator
+";
    while ($i->hasNext()) { 
         print $filehandle $i->next();
    }
}
[download]

Now, consider the following code which uses it.

serialize_stuff_to_file(Array::Iterator->new(@array));
serialize_stuff_to_file(ArrayOfArrays::Iterator->new(@array));
serialize_stuff_to_file(ArrayOfHashes::Iterator->new(@array));
serialize_stuff_to_file(Hash::Iterator->new(%hash));
serialize_stuff_to_file(HashOfHashes::Iterator->new(%hash));
serialize_stuff_to_file(HashOfArrays::Iterator->new(%hash));
serialize_stuff_to_file(Tree::Iterator->new($tree));
[download]

Since I know the Iterator will always respond to the same methods, and always produce the expected result on each loop, I can ignore the underlying structure of the object being iterated over. IMO, this is where MJD's argument that foreach is an iterator breaks down.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.