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