However, I just realized I had another function in that library that could perform the task you described, although it would be overkill. It's called something like move-muldim-block; it takes a multi-dimensional list and returns a new multi-dimensional list with a multi-dimensional piece of that list moved elsewhere, using a combining function to determing the value of the area in which it was moved (I used it in Sokoban to simplify code that would let let me move a crate character onto a storage character and change it to the crate-on-storate character).
In other words, if lst is set to ((1 2) (3 4)) and f is some function, (move-muldim block (list 1 0) (list 1 2) (list 0 0) +) would be equivalent to (((+ 1 3) (+ 2 4)) ((f 3) (f 4))) (it moves a 1x2 block from coordinates (1 0) to coordinates (0 0)). Just take the car of the result and you have what you're looking for (in which case, we could omit the last argument and use the default value).
For this specific task, apply is a heck of a lot simpler, but I can still post the code if you're interested. I personally found it very interesting to realize that this could be done, and that muldim-move-block is a little more useful than I first thought.
Hmm. Right now I store the positions of my mobile piec elsewhere than in the world-list. Your function might be handy later on. I haven't yet decided if I want every actor of the world stored in the world (even if some of them might overlap), or store the mobile actors in a separate list.
Right now the thing about sokoban implementations that would interest me most is if you've done anything fancy to generate the output. Having an update of a 2d world scroll by ever so often makes it hard to track movement of a single character through this world. Did you work on that?
Since Arc is a language targeted for the web... have you considered the possibility of generating a web page for it, with maybe next >> and << prev links?
That might actually work, and just autorefresh the page every second or so :)
First priorities now are finishing the wandering algorithm for the animals so that they're no longer steered but steer themselves, and generalize the code I've some more so that adding more behaviours than just biting things is easy. I'll add the visuals-through webpage idea to that list :)
Sorry, not really. I just used a simple function to print out a 2-dimensional list and resized my terminal window so that the grid would be in the same place after every sequence of moves, which gives the illusion that the same grid is being redrawn.
Small mistake -- the invocation would be (move-muldim block (list 1 0) (list 1 2) (list 0 0) + f) (I hope no-one thought I'd be silly enough to set the function to find the replacement-fn by looking up the global value of f...).
