I have been thinking about this, and i am posotive that something like this has been discussed on the mechanics mega thread, but since i cant find that thread i will post it here.
This workshop realy is a bit artificialy limited at the moment. If you think about it once wall movement is in there realy is no reason it should not work in any direction. But of course there are a whole host of problems that come with it. What happens when it comes in contact with a construction? A table? A workshop? A natural wall? What about walls and chairs and other stuff on top of it? Here is how i would adress the issues:
1. New item, the wall segment. Made from wood, stone or metal.
2. New shop: driver. It is 3x3, but could be 1x1 with a higher power requirement. Needs 6 mechanisms and 6 blocks. Bsase power is 100.
Wall segments are unsuporting but blocking (like a door of floodgate), and can be walked on (like a raised bridge if i remember correctly) removing any concers about what to do with attached constructions. They just collaps. They exsist in 2 states, attached an unattached. Unattached act like any other unbuilt funiture. To attach wall segments build a driver shop, assign a build direction and start huffing wall segments over to it. The wall segments add 5 to 10 power per segment, and extend out in the direction specified. If the leading segment is not a wall segment but instead is a bit, then the wall is not stopped by consrtuctions or natural walls. These are simply destroyed (no rock left behind). Similarly any funiture, buildings, other connected wall segments, items or units are also destroyed. If it is a wall segment leading walls of any kind stop all progess. Workshops, built funiture and the like are unbuilt and pushed along like normal items, taking mild durrability damage. Units are also bludgeoned as they are pushed. Stuff caught between a wall segment and another wall are crushed.
Once you have attached as many segments as you want you could then "lock" the shop. What this means is that when the workshop is set to retract instead of deattaching segments, causing the shop to get more cluttered and work slower, the segments are instead passed out the other side still attached. They will move as far as they can untill they are blocked. Anything between the segment and the wall is, again, crushed.
The shop extension is controled by a lever, and is either extending or retracting. Wall segments are requested at the shop, and are selected like building constructions. There should also be a queue function, so you could say get these 3 wood walls, this microline wall, and that gold one, in that order. As long as the shop is set to extend mode new walls brought to the shop are automaticaly added and extended.
With a setup like this we could build multiple types of objects, such as retracting briges, multi tile and multi level gates (just stack shops on top of eache other and hook them to the same lever) huge floodgates, smashing room death traps, crude lever operated elivators, simple tunnel boring machines, fast water movers and crude piston pumps (along with a way to raise water to a level without a pump on it) and the original pile driver idea. And since none of these are specialised functions it relay keep up with the whole sandbox feel of the consruction enviroment.
Issues: i do not know if the map data is capable of storing the attachment associations required. Objet/liquid pushing also may not be handled currently, since the only instance of moving tiles i know of destroys liqids in the way, instead of pushing them out of the way. Other than that it looks like the game engine can already handle what this needs to work.
A mod realy needs to move this and leave me a link to the mechanics megathread....