Start making Pattern.either to expand any pattern to Either.

docopt.py

@@ -37,6 +37,29 @@ def flat(self):
             return [self]
         return sum([c.flat for c in self.children], [])
 
+    @property
+    def either(self):
+        if not hasattr(self, 'children'):
+            return Either(self)
+        else:
+            ret = []
+            groups = [list(deepcopy(self.children))]
+            #groups = [self]
+            while groups:
+                children = groups.pop(0)
+                eithers = [c for c in children if type(c) == Either]
+                if len(eithers):
+                    either = eithers[0]
+                    children.pop(children.index(either))
+                    for c in either.children:
+                        groups.append([c] + children)
+                        print groups
+                else:
+                    ret.append(children)
+            return Either(*[Required(*e) for e in ret])
+
+
+
 
 class Argument(Pattern):
 

test_docopt.py

@@ -248,3 +248,17 @@ def test_basic_pattern_matching():
     assert pattern.match([Option('x'),
                           Argument(None, 9), Argument(None, 5)]) == (
                                                               False, [], [])
+
+
+def test_pattern_either():
+    assert Option('a').either == Either(Option('a'))
+    assert Argument('a').either == Either(Argument('a'))
+    assert Required(Either(Option('a'), Option('b')), Option('c')).either == \
+            Either(Required(Option('a'), Option('c')),
+                   Required(Option('b'), Option('c')))
+    assert Required(Option('a'), Either(Option('b'), Option('c'))).either == \
+            Either(Required(Option('b'), Option('a')),
+                   Required(Option('c'), Option('a')))
+#   print Either(Option('x'), Either(Option('y'), Option('z'))).either
+#   assert Either(Option('x'), Either(Option('y'), Option('z'))).either == \
+#           Either(Option('z'), Option('y'), Option('z'))