1 # Coroutine example: controlling multiple instances of a single function 2 3 from Coroutine import * 4 5 # fringe visits a nested list in inorder, and detaches for each non-list 6 # element; raises EarlyExit after the list is exhausted 7 def fringe(co, list): 8 for x in list: 9 if type(x) is type([]): 10 fringe(co, x) 11 else: 12 co.back(x) 13 14 def printinorder(list): 15 co = Coroutine() 16 f = co.create(fringe, co, list) 17 try: 18 while 1: 19 print co.tran(f), 20 except EarlyExit: 21 pass 22 print 23 24 printinorder([1,2,3]) # 1 2 3 25 printinorder([[[[1,[2]]],3]]) # ditto 26 x = [0, 1, [2, [3]], [4,5], [[[6]]] ] 27 printinorder(x) # 0 1 2 3 4 5 6 28 29 # fcmp lexicographically compares the fringes of two nested lists 30 def fcmp(l1, l2): 31 co1 = Coroutine(); f1 = co1.create(fringe, co1, l1) 32 co2 = Coroutine(); f2 = co2.create(fringe, co2, l2) 33 while 1: 34 try: 35 v1 = co1.tran(f1) 36 except EarlyExit: 37 try: 38 v2 = co2.tran(f2) 39 except EarlyExit: 40 return 0 41 co2.kill() 42 return -1 43 try: 44 v2 = co2.tran(f2) 45 except EarlyExit: 46 co1.kill() 47 return 1 48 if v1 != v2: 49 co1.kill(); co2.kill() 50 return cmp(v1,v2) 51 52 print fcmp(range(7), x) # 0; fringes are equal 53 print fcmp(range(6), x) # -1; 1st list ends early 54 print fcmp(x, range(6)) # 1; 2nd list ends early 55 print fcmp(range(8), x) # 1; 2nd list ends early 56 print fcmp(x, range(8)) # -1; 1st list ends early 57 print fcmp([1,[[2],8]], 58 [[[1],2],8]) # 0 59 print fcmp([1,[[3],8]], 60 [[[1],2],8]) # 1 61 print fcmp([1,[[2],8]], 62 [[[1],2],9]) # -1 63 64 # end of example 65
