My last comment was... regrettable. Poorly worded. Also, wrong. And pretty much everyone's been calling me on it.
So: here is the REAL problem with randomly generated strings.
Let’s say we start throwing random strings at the player, instead of pre-made tests. Many of the ‘accept’ levels have pretty stringent conditions – so most of the tests will fail. This means that the player can just run their machine repeatedly and, with a little patience, they’ll end up passing no matter whether their solution is valid or not. (Even if it’s just an empty grid – if all the strings are supposed to fail, then that’ll pass!)
We can start to constrain the strings we give – say, ‘half will accept, and the other half will reject’. Then we start to encounter the problem of randomly generating strings that match a specific pattern. This is a pretty tricky thing to do, in general – and we still have the problem that they may just, well, randomly allow a flawed solution to pass…
Comment split in two for length reasons:
Shrag: the problem with generating patterns randomly is that the game would have to know whether the patterns it generated were acceptable or not. That is... somewhere between "very hard" and "impossible." It's related to "http://en.wikipedia.org/wiki/Halting_problem"
:this.
Vergilius: I know I was a bit terse in places, especially when it came to the binary. What in particular struck you as obtuse or poorly explained?
Developer here!
Can't reply to everything, obviously - and this isn't a very good space to reply at all (if you want to guarantee that your suggestion/complaint will be replied to, try the "tigsource feedback thread":http://forums.tigsource.com/index.php?board=6.0 or "http://www.formspring.me/PleasingFungus":formspring!), but here's a few things.
CeruleanDragon: there are actually longer tooltips that appear if you hover over the items in question (or anything, for that matter!) for longer. If you didn't find those, though, that's my fault as a designer, not yours as a player. I'll look into explaining that better.
 "i find no love in this passionless life"){kind=icon}
 "1924"){kind=icon}
 "Manufactoria"){kind=icon}