+def buildtravel(locs, objs):
+ assert len(locs) <= 300
+ assert len(objs) <= 100
+ # THIS CODE IS WAAAY MORE COMPLEX THAN IT NEEDS TO BE. It's the
+ # result of a massive refactoring exercise that concentrated all
+ # the old nastiness in one spot. It hasn't been finally simplified
+ # because there's no need to do it until one of the asserions
+ # fails. Hint: if you try cleaning this up, the acceptance test is
+ # simple - the output dungeon.c must not change.
+ #
+ # This function first compiles the YAML to a form identical to the
+ # data in section 3 of the old adventure.text file, then a second
+ # stage unpacks that data into the travel array. Here are the
+ # rules of that intermediate form:
+ #
+ # Each row of data contains a location number (X), a second
+ # location number (Y), and a list of motion numbers (see section 4).
+ # each motion represents a verb which will go to Y if currently at X.
+ # Y, in turn, is interpreted as follows. Let M=Y/1000, N=Y mod 1000.
+ # If N<=300 it is the location to go to.
+ # If 300<N<=500 N-300 is used in a computed goto to
+ # a section of special code.
+ # If N>500 message N-500 from section 6 is printed,
+ # and he stays wherever he is.
+ # Meanwhile, M specifies the conditions on the motion.
+ # If M=0 it's unconditional.
+ # If 0<M<100 it is done with M% probability.
+ # If M=100 unconditional, but forbidden to dwarves.
+ # If 100<M<=200 he must be carrying object M-100.
+ # If 200<M<=300 must be carrying or in same room as M-200.
+ # If 300<M<=400 game.prop(M % 100) must *not* be 0.
+ # If 400<M<=500 game.prop(M % 100) must *not* be 1.
+ # If 500<M<=600 game.prop(M % 100) must *not* be 2, etc.
+ # If the condition (if any) is not met, then the next *different*
+ # "destination" value is used (unless it fails to meet *its* conditions,
+ # in which case the next is found, etc.). Typically, the next dest will
+ # be for one of the same verbs, so that its only use is as the alternate
+ # destination for those verbs. For instance:
+ # 15 110022 29 31 34 35 23 43
+ # 15 14 29
+ # This says that, from loc 15, any of the verbs 29, 31, etc., will take
+ # him to 22 if he's carrying object 10, and otherwise will go to 14.
+ # 11 303008 49
+ # 11 9 50
+ # This says that, from 11, 49 takes him to 8 unless game.prop[3]=0, in which
+ # case he goes to 9. Verb 50 takes him to 9 regardless of game.prop[3].