1 files changed, 105 insertions, 0 deletions
diff --git a/events.py b/events.py
new file mode 100644
index 0000000..e1b9c62
--- /dev/null
+++ b/events.py
@@ -0,0 +1,105 @@
+
+# Abstract classes.
+
+
+def CommentCheck():
+    pass
+
+
+class Event(object):
+    def __init__(self, start_mark=None, end_mark=None, comment=CommentCheck):
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        # assert comment is not CommentCheck
+        if comment is CommentCheck:
+            comment = None
+        self.comment = comment
+
+    def __repr__(self):
+        attributes = [key for key in ['anchor', 'tag', 'implicit', 'value',
+                                      'flow_style', 'style']
+                      if hasattr(self, key)]
+        arguments = ', '.join(['%s=%r' % (key, getattr(self, key))
+                               for key in attributes])
+        if self.comment not in [None, CommentCheck]:
+            arguments += ', comment={!r}'.format(self.comment)
+        return '%s(%s)' % (self.__class__.__name__, arguments)
+
+
+class NodeEvent(Event):
+    def __init__(self, anchor, start_mark=None, end_mark=None, comment=None):
+        Event.__init__(self, start_mark, end_mark, comment)
+        self.anchor = anchor
+
+
+class CollectionStartEvent(NodeEvent):
+    def __init__(self, anchor, tag, implicit, start_mark=None, end_mark=None,
+                 flow_style=None, comment=None):
+        Event.__init__(self, start_mark, end_mark, comment)
+        self.anchor = anchor
+        self.tag = tag
+        self.implicit = implicit
+        self.flow_style = flow_style
+
+
+class CollectionEndEvent(Event):
+    pass
+
+# Implementations.
+
+
+class StreamStartEvent(Event):
+    def __init__(self, start_mark=None, end_mark=None, encoding=None,
+                 comment=None):
+        Event.__init__(self, start_mark, end_mark, comment)
+        self.encoding = encoding
+
+
+class StreamEndEvent(Event):
+    pass
+
+
+class DocumentStartEvent(Event):
+    def __init__(self, start_mark=None, end_mark=None,
+                 explicit=None, version=None, tags=None, comment=None):
+        Event.__init__(self, start_mark, end_mark, comment)
+        self.explicit = explicit
+        self.version = version
+        self.tags = tags
+
+
+class DocumentEndEvent(Event):
+    def __init__(self, start_mark=None, end_mark=None,
+                 explicit=None, comment=None):
+        Event.__init__(self, start_mark, end_mark, comment)
+        self.explicit = explicit
+
+
+class AliasEvent(NodeEvent):
+    pass
+
+
+class ScalarEvent(NodeEvent):
+    def __init__(self, anchor, tag, implicit, value,
+                 start_mark=None, end_mark=None, style=None, comment=None):
+        NodeEvent.__init__(self, anchor, start_mark, end_mark, comment)
+        self.tag = tag
+        self.implicit = implicit
+        self.value = value
+        self.style = style
+
+
+class SequenceStartEvent(CollectionStartEvent):
+    pass
+
+
+class SequenceEndEvent(CollectionEndEvent):
+    pass
+
+
+class MappingStartEvent(CollectionStartEvent):
+    pass
+
+
+class MappingEndEvent(CollectionEndEvent):
+    pass