def execute(self, agent, x, y, env):
newEnv = Environment()
prereqs = [("holding", agent, x)]
deletions = prereqs
additions = [("empty", agent), ("on", x, y), ("clear", x)]
if not y == "ground":
prereqs.append(("clear", y))
for prereq in prereqs:
if not prereq in env.relations:
return None
newRelations = env.relations[:]
for deletion in deletions:
newRelations.remove(deletion)
for addition in additions:
newRelations.append(addition)
newEnv.relations = newRelations;
newEnv.steps = env.steps[:]
newEnv.steps.append(("putDown", agent, x, y))
return newEnv
def findNextEnv(prereqs, additions, deletions, relations):
for prereq in prereqs:
if not prereq in relations:
return None
newRelations = relations[:]
for deletion in deletions:
newRelations.remove(deletion)
for addition in additions:
newRelations.append(addition)
newEnv = Environment()
newEnv.relations = newRelations
return newEnv
