fix merge, iteration, reused anchors0.12.3

6 files changed, 191 insertions, 24 deletions

diff --git a/README.rst b/README.rst
index c54aed5..7a303d7 100644
--- a/README.rst
+++ b/README.rst
@@ -17,10 +17,20 @@ ChangeLog
 =========
 
 ::
-  0.12.3 (XXXX-XX-XX):
-  - correct 'in' operation for merged CommentedMaps in round-trip mode
-   (implementation inspired by J.Ngo, but original not working for merges)
-  - iteration over round-trip loaded mappings, as well as 
+
+  0.12.3 (2016-08-17):
+    - correct 'in' operation for merged CommentedMaps in round-trip mode
+      (implementation inspired by J.Ngo, but original not working for merges)
+    - iteration over round-trip loaded mappings, that contain merges. Also
+      keys(), items(), values() (Py3/Py2) and iterkeys(), iteritems(),
+      itervalues(), viewkeys(), viewitems(), viewvalues() (Py2)
+    - reuse of anchor name now generates warning, not an error. Round-tripping such
+      anchors works correctly. This inherited PyYAML issue was brought to attention
+      by G. Coddut (and was long standing https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=515634)
+      suppressing the warning:
+          import warnings
+          from ruamel.yaml.error import ReusedAnchorWarning
+          warnings.simplefilter("ignore", ReusedAnchorWarning)
 
   0.12.2 (2016-08-16):
     - minor improvements based on feedback from M. Crusoe
diff --git a/__init__.py b/__init__.py
index a7817d0..5e4cdfd 100644
--- a/__init__.py
+++ b/__init__.py
@@ -9,7 +9,7 @@ from __future__ import absolute_import
 
 _package_data = dict(
     full_package_name="ruamel.yaml",
-    version_info=(0, 12, 2, "dev"),
+    version_info=(0, 12, 3),
     author="Anthon van der Neut",
     author_email="a.van.der.neut@ruamel.eu",
     description="ruamel.yaml is a YAML parser/emitter that supports roundtrip preservation of comments, seq/map flow style, and map key order",  # NOQA
diff --git a/_test/test_anchor.py b/_test/test_anchor.py
index 1c795c0..593bf8a 100644
--- a/_test/test_anchor.py
+++ b/_test/test_anchor.py
@@ -9,6 +9,8 @@ from textwrap import dedent
 import platform
 
 from roundtrip import round_trip, dedent, round_trip_load, round_trip_dump  # NOQA
+from ruamel.yaml.compat import PY3
+from ruamel.yaml.error import ReusedAnchorWarning
 
 
 def load(s):
@@ -228,6 +230,19 @@ class TestAnchorsAliases:
         b: 2
         """)
 
+    # this is an error in PyYAML
+    def test_reused_anchor(self):
+        yaml = '''
+        - &a
+          x: 1
+        - <<: *a
+        - &a
+          x: 2
+        - <<: *a
+        '''
+        with pytest.warns(ReusedAnchorWarning):
+            data = round_trip(yaml)  # NOQA
+
 
 class TestMergeKeysValues:
 
@@ -247,6 +262,8 @@ class TestMergeKeysValues:
       <<: *my
         """)
 
+    # in the following d always has "expanded" the merges
+
     def test_merge_for(self):
         from ruamel.yaml import safe_load
         d = safe_load(self.yaml_str)
@@ -286,3 +303,23 @@ class TestMergeKeysValues:
             count += 1
             print(count, x)
         assert count == len(d[2])
+
+    def test_len_items_delete(self):
+        from ruamel.yaml import safe_load
+        d = safe_load(self.yaml_str)
+        data = round_trip_load(self.yaml_str)
+        x = data[2].items()
+        ref = len(d[2].items())
+        assert len(x) == ref
+        del data[2]['m']
+        if PY3:
+            ref -= 1
+        assert len(x) == ref
+        del data[2]['d']
+        if PY3:
+            ref -= 1
+        assert len(x) == ref
+        del data[2]['a']
+        if PY3:
+            ref -= 1
+        assert len(x) == ref
diff --git a/comments.py b/comments.py
index 26587ce..c3d17b0 100644
--- a/comments.py
+++ b/comments.py
@@ -8,7 +8,7 @@ these are not really related, formatting could be factored out as
 a separate base
 """
 
-from collections import MutableSet  # type: ignore
+from collections import MutableSet, Sized, Set  # type: ignore
 
 from ruamel.yaml.compat import ordereddict, PY2
 
@@ -321,6 +321,87 @@ class CommentedSeq(list, CommentedBase):
         return pre_comments
 
 
+class CommentedMapView(Sized):
+
+    __slots__ = '_mapping',
+
+    def __init__(self, mapping):
+        self._mapping = mapping
+
+    def __len__(self):
+        count = len(self._mapping)
+        done = []  # list of processed merge items, kept for masking
+        for merged in getattr(self._mapping, merge_attrib, []):
+            for x in merged[1]:
+                if self._mapping._unmerged_contains(x):
+                    continue
+                for y in done:
+                    if x in y:
+                        break
+                else:
+                    count += 1
+            done.append(merged[1])
+        return count
+
+    def __repr__(self):
+        return '{0.__class__.__name__}({0._mapping!r})'.format(self)
+
+
+class CommentedMapKeysView(CommentedMapView, Set):
+
+    __slots__ = ()
+
+    @classmethod
+    def _from_iterable(self, it):
+        return set(it)
+
+    def __contains__(self, key):
+        return key in self._mapping
+
+    def __iter__(self):
+        # yield from self._mapping  # not in py27, pypy
+        for x in self._mapping:
+            yield x
+
+
+class CommentedMapItemsView(CommentedMapView, Set):
+
+    __slots__ = ()
+
+    @classmethod
+    def _from_iterable(self, it):
+        return set(it)
+
+    def __contains__(self, item):
+        key, value = item
+        try:
+            v = self._mapping[key]
+        except KeyError:
+            return False
+        else:
+            return v == value
+
+    def __iter__(self):
+        for key in self._mapping._keys():
+            yield (key, self._mapping[key])
+
+
+class CommentedMapValuesView(CommentedMapView):
+
+    __slots__ = ()
+
+    def __contains__(self, value):
+        for key in self._mapping:
+            if value == self._mapping[key]:
+                return True
+        return False
+
+    def __iter__(self):
+        print('xxy values_iter')
+        for key in self._mapping:
+            yield self._mapping[key]
+
+
 class CommentedMap(ordereddict, CommentedBase):
     __slots__ = [Comment.attrib, ]
 
@@ -425,6 +506,10 @@ class CommentedMap(ordereddict, CommentedBase):
                     return merged[1][key]
             raise
 
+    def _unmerged_contains(self, key):
+        if ordereddict.__contains__(self, key):
+            return True
+
     def __contains__(self, key):
         if ordereddict.__contains__(self, key):
             return True
@@ -444,6 +529,20 @@ class CommentedMap(ordereddict, CommentedBase):
         for x in ordereddict.__iter__(self):
             yield x, ordereddict.__getitem__(self, x)
 
+    def __delitem__(self, key):
+        found = True
+        for merged in getattr(self, merge_attrib, []):
+            try:
+                del merged[1][key]
+                found = True
+            except KeyError:
+                pass
+        try:
+            ordereddict.__delitem__(self, key)
+        except KeyError:
+            if not found:
+                raise
+
     def __iter__(self):
         for x in ordereddict.__iter__(self):
             yield x
@@ -477,11 +576,15 @@ class CommentedMap(ordereddict, CommentedBase):
     if PY2:
         def keys(self):
             return list(self._keys())
+
+        def iterkeys(self):
+            return self._keys()
+
+        def viewkeys(self):
+            return CommentedMapKeysView(self)
     else:
-        # def keys(self):
-        #     import collections
-        #     return collections.KeysView(self._keys())
-        keys = _keys
+        def keys(self):
+            return CommentedMapKeysView(self)
 
     def _values(self):
         for x in ordereddict.__iter__(self):
@@ -501,11 +604,15 @@ class CommentedMap(ordereddict, CommentedBase):
     if PY2:
         def values(self):
             return list(self._values())
+
+        def itervalues(self):
+            return self._values()
+
+        def viewvalues(self):
+            return CommentedMapValuesView(self)
     else:
-        # def values(self):
-        #     import collections
-        #     return collections.ValuesView(self)
-        values = _values
+        def values(self):
+            return CommentedMapValuesView(self)
 
     def _items(self):
         for x in ordereddict.__iter__(self):
@@ -525,11 +632,15 @@ class CommentedMap(ordereddict, CommentedBase):
     if PY2:
         def items(self):
             return list(self._items())
+
+        def iteritems(self):
+            return self._items()
+
+        def viewitems(self):
+            return CommentedMapItemsView(self)
     else:
-        # def items(self):
-        #    import collections
-        #    return collections.ItemsView(self._items())
-        items = _items
+        def items(self):
+            return CommentedMapItemsView(self)
 
     @property
     def merge(self):
diff --git a/composer.py b/composer.py
index 320fb22..791bf50 100644
--- a/composer.py
+++ b/composer.py
@@ -3,8 +3,9 @@
 from __future__ import absolute_import
 from __future__ import print_function
 
+import warnings
 
-from ruamel.yaml.error import MarkedYAMLError
+from ruamel.yaml.error import MarkedYAMLError, ReusedAnchorWarning
 from ruamel.yaml.compat import utf8
 
 from ruamel.yaml.events import (
@@ -87,10 +88,14 @@ class Composer(object):
         anchor = event.anchor
         if anchor is not None:  # have an anchor
             if anchor in self.anchors:
-                raise ComposerError(
-                    "found duplicate anchor %r; first occurence"
-                    % utf8(anchor), self.anchors[anchor].start_mark,
-                    "second occurence", event.start_mark)
+                # raise ComposerError(
+                #     "found duplicate anchor %r; first occurence"
+                #     % utf8(anchor), self.anchors[anchor].start_mark,
+                #     "second occurence", event.start_mark)
+                ws = "\nfound duplicate anchor {!r}\nfirst occurence {}\nsecond occurence "\
+                     "{}".format(
+                         (anchor), self.anchors[anchor].start_mark, event.start_mark)
+                warnings.warn(ws, ReusedAnchorWarning)
         self.descend_resolver(parent, index)
         if self.check_event(ScalarEvent):
             node = self.compose_scalar_node(anchor)
diff --git a/error.py b/error.py
index fb5e78c..e93c20e 100644
--- a/error.py
+++ b/error.py
@@ -4,7 +4,7 @@ from __future__ import absolute_import
 
 from ruamel.yaml.compat import utf8
 
-__all__ = ['Mark', 'YAMLError', 'MarkedYAMLError']
+__all__ = ['Mark', 'YAMLError', 'MarkedYAMLError', 'ReusedAnchorWarning']
 
 
 class Mark(object):
@@ -80,3 +80,7 @@ class MarkedYAMLError(YAMLError):
         if self.note is not None:
             lines.append(self.note)
         return '\n'.join(lines)
+
+
+class ReusedAnchorWarning(Warning):
+    pass