Comments on: Actual programming with HTML and CSS (without javascript)

By: Jakob

Jakob — Tue, 08 Mar 2011 22:44:54 +0000

CSS3 just has proven to be Turing-Complete. You only need a veeeeery large HTML document.

By: Kevembuangga

Kevembuangga — Wed, 13 Jan 2010 03:13:58 +0000

it does not qualify as a bona fide Turing tar pit.

I CAN tell you it does!

By: Daniel Lemire

Daniel Lemire — Tue, 12 Jan 2010 15:50:47 +0000

@Kevembuangga People do useful things with CSS all the time, so it does not qualify as a bona fide Turing tar pit.

By: Kevembuangga

Kevembuangga — Tue, 12 Jan 2010 15:28:10 +0000

Sheesh…
A Turing Tar Pit which isn’t even Turing complete!

By: Ian

Ian — Mon, 11 Jan 2010 18:31:31 +0000

My instinct is that it is not, because you can’t delete characters on the ‘tape’. Counters and generators provide some limited computation ability but it’s not arbitrary and requires significant setup in the HTML to do anything big. Proving Turing-completeness is done by reducing a known Turing-complete language to the target… I haven’t seen that done.

By: Daniel Lemire

Daniel Lemire — Mon, 11 Jan 2010 17:15:17 +0000

@JeffE Good old CSS is certainly not Turing complete. Is CSS3 Turing complete? I would be surprised, but please, suprise me! References: Wieser, C., CSS NG: An Extension of the Cascading Styles Sheets Language (CSS) with Dynamic Document Rendering Features, 2006. Kepser, S., A simple proof for the Turing-completeness of XSLT and XQuery, Extreme Markup Languages, 2004

By: JeffE

JeffE — Mon, 11 Jan 2010 16:48:10 +0000

It’s not Turing-complete? Really? Seems like you could have all sort of fun with counters and ‘move-to’.

By: Daniel Lemire

Daniel Lemire — Mon, 11 Jan 2010 16:16:14 +0000

@mattcopp

I’d like to know myself whether it works under Internet Explorer.

By: Robin Millette

Robin Millette — Mon, 11 Jan 2010 16:11:46 +0000

In 1997 or so, I wrote a small game in html (no javascript) that used the timed refresh meta. It showed a screen with images, good and bad guys, where you had to “shoot” the bad guy first. If you waited to long, you were shot. If you shot a good guy, you would loose as well. Not much for a game, but I was happy it could all be done with plain HTML

By: mattcopp

mattcopp — Mon, 11 Jan 2010 16:10:23 +0000

This is a fantastic discovery. Completely novel to me, but I am concerned about browser compatibility. It looks like CSS3 so you can count out most IEs. What have you found?