Source Code for Module SmootLight.util.BehaviorQuerySystem

 1  import types  
 2  """The behavior query system is a module that allows querying behaviors based on lambda-function 
 3  predicates.""" 
 4 -def initBQS(): 
 5      global behaviorList, initialized 
 6      behaviorList = []  
 7      initialized = True 
 8   
 9 -def addBehavior(behavior): 
10      """Add a behavior to the behavior registry.""" 
11      behaviorList.append(behavior) 
12   
13 -def query(predicateList): 
14      """BehaviorQuerySystem.query takes a list of predicates (functions with signature: 
15          (behavior,output)), and 
16      optionally a behavior to be compared to.""" 
17      #want to do queries wrt: behavior itself, the behavior packet, the querying behavior 
18      if isinstance(predicateList, types.FunctionType): 
19          predicateList = [predicateList] 
20      elif not isinstance(predicateList, list): 
21          raise Exception('Predicate list must be a function or list of functions') 
22      global behaviorList, initialized 
23      ret = []  
24      if not initialized: 
25          initBQS() 
26       
27      for behavior in behaviorList: #Consider every behavior 
28          lastOutput = behavior.getLastOutput() 
29          for output in lastOutput: #Look at every element it has output 
30              validOutput = True 
31              for pred in predicateList: #Evaluate every predicate.  A predicate is a lambda function that 
32              #takes a dict and returns a bool. 
33                  if not pred(output): 
34                      validOutput = False 
35                      break 
36              if validOutput: 
37                  ret.append(output) 
38      return ret  
39   
40 -def getDistLambda(loc, maxDist): 
41      """Returns a lambda function that checks if for behaviors within maxDist of loc.  Can be passed 
42      in as an arg to query.""" 
43      return lambda args:geo.dist(args['Location'], loc) <= maxDist 
44   
45 -def getBehaviorsNear(loc, maxdist): 
46      """A premade method to do the common task of finding behavior near a location.""" 
47      return query(getDistLambda(loc, maxDist)) 
48