1 files changed, 164 insertions, 0 deletions
diff --git a/qpid/python/mllib/transforms.py b/qpid/python/mllib/transforms.py
new file mode 100644
index 0000000000..69d99125e3
--- /dev/null
+++ b/qpid/python/mllib/transforms.py
@@ -0,0 +1,164 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+# 
+#   http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+"""
+Useful transforms for dom objects.
+"""
+
+import dom
+from cStringIO import StringIO
+
+class Visitor:
+
+  def descend(self, node):
+    for child in node.children:
+      child.dispatch(self)
+
+  def node(self, node):
+    self.descend(node)
+
+  def leaf(self, leaf):
+    pass
+
+class Identity:
+
+  def descend(self, node):
+    result = []
+    for child in node.children:
+      result.append(child.dispatch(self))
+    return result
+
+  def default(self, tag):
+    result = dom.Tag(tag.name, *tag.attrs)
+    result.extend(self.descend(tag))
+    return result
+
+  def tree(self, tree):
+    result = dom.Tree()
+    result.extend(self.descend(tree))
+    return result
+
+  def tag(self, tag):
+    return self.default(tag)
+
+  def leaf(self, leaf):
+    return leaf.__class__(leaf.data)
+
+class Sexp(Identity):
+
+  def __init__(self):
+    self.stack = []
+    self.level = 0
+    self.out = ""
+
+  def open(self, s):
+    self.out += "(%s" % s
+    self.level += len(s) + 1
+    self.stack.append(s)
+
+  def line(self, s = ""):
+    self.out = self.out.rstrip()
+    self.out += "\n" + " "*self.level + s
+
+  def close(self):
+    s = self.stack.pop()
+    self.level -= len(s) + 1
+    self.out = self.out.rstrip()
+    self.out += ")"
+
+  def tree(self, tree):
+    self.open("+ ")
+    for child in tree.children:
+      self.line(); child.dispatch(self)
+    self.close()
+
+  def tag(self, tag):
+    self.open("Node(%s) " % tag.name)
+    for child in tag.children:
+      self.line(); child.dispatch(self)
+    self.close()
+
+  def leaf(self, leaf):
+    self.line("%s(%s)" % (leaf.__class__.__name__, leaf.data))
+
+class Output:
+
+  def descend(self, node):
+    out = StringIO()
+    for child in node.children:
+      out.write(child.dispatch(self))
+    return out.getvalue()
+
+  def default(self, tag):
+    out = StringIO()
+    out.write("<%s" % tag.name)
+    for k, v in tag.attrs:
+      out.write(' %s="%s"' % (k, v))
+    out.write(">")
+    out.write(self.descend(tag))
+    if not tag.singleton:
+      out.write("</%s>" % tag.name)
+    return out.getvalue()
+
+  def tree(self, tree):
+    return self.descend(tree)
+
+  def tag(self, tag):
+    return self.default(tag)
+
+  def data(self, leaf):
+    return leaf.data
+
+  def entity(self, leaf):
+    return "&%s;" % leaf.data
+
+  def character(self, leaf):
+    raise Exception("TODO")
+
+  def comment(self, leaf):
+    return "<!-- %s -->" % leaf.data
+
+class Empty(Output):
+
+  def tag(self, tag):
+    return self.descend(tag)
+
+  def data(self, leaf):
+    return ""
+
+  def entity(self, leaf):
+    return ""
+
+  def character(self, leaf):
+    return ""
+
+  def comment(self, leaf):
+    return ""
+
+class Text(Empty):
+
+  def data(self, leaf):
+    return leaf.data
+
+  def entity(self, leaf):
+    return "&%s;" % leaf.data
+
+  def character(self, leaf):
+    # XXX: is this right?
+    return "&#%s;" % leaf.data