Add 1994 Coroutine module by Tim Peters

Demo/threads/fcmp.py

@@ -0,0 +1,64 @@
+# Coroutine example:  controlling multiple instances of a single function
+
+from Coroutine import *
+
+# fringe visits a nested list in inorder, and detaches for each non-list
+# element; raises EarlyExit after the list is exhausted
+def fringe( co, list ):
+    for x in list:
+        if type(x) is type([]):
+            fringe(co, x)
+        else:
+            co.detach(x)
+
+def printinorder( list ):
+    co = Coroutine()
+    f = co.create(fringe, co, list)
+    try:
+        while 1:
+            print co.tran(f),
+    except EarlyExit:
+        pass
+    print
+
+printinorder([1,2,3])  # 1 2 3
+printinorder([[[[1,[2]]],3]]) # ditto
+x = [0, 1, [2, [3]], [4,5], [[[6]]] ]
+printinorder(x) # 0 1 2 3 4 5 6
+
+# fcmp lexicographically compares the fringes of two nested lists
+def fcmp( l1, l2 ):
+    co1 = Coroutine(); f1 = co1.create(fringe, co1, l1)
+    co2 = Coroutine(); f2 = co2.create(fringe, co2, l2)
+    while 1:
+        try:
+            v1 = co1.tran(f1)
+        except EarlyExit:
+            try:
+                v2 = co2.tran(f2)
+            except EarlyExit:
+                return 0
+            co2.kill()
+            return -1
+        try:
+            v2 = co2.tran(f2)
+        except EarlyExit:
+            co1.kill()
+            return 1
+        if v1 != v2:
+            co1.kill(); co2.kill()
+            return cmp(v1,v2)
+
+print fcmp(range(7), x)  #  0; fringes are equal
+print fcmp(range(6), x)  # -1; 1st list ends early
+print fcmp(x, range(6))  #  1; 2nd list ends early
+print fcmp(range(8), x)  #  1; 2nd list ends early
+print fcmp(x, range(8))  # -1; 1st list ends early
+print fcmp([1,[[2],8]],
+           [[[1],2],8])  #  0
+print fcmp([1,[[3],8]],
+           [[[1],2],8])  #  1
+print fcmp([1,[[2],8]],
+           [[[1],2],9])  # -1
+
+# end of example