1 files changed, 68 insertions, 0 deletions
diff --git a/registry/spec_tools/util.py b/registry/spec_tools/util.py
new file mode 100644
index 0000000..2463290
--- /dev/null
+++ b/registry/spec_tools/util.py
@@ -0,0 +1,68 @@
+"""Utility functions not closely tied to other spec_tools types."""
+# Copyright (c) 2018-2019 Collabora, Ltd.
+# Copyright (c) 2013-2019 The Khronos Group Inc.
+#
+# Licensed 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.
+
+
+def getElemName(elem, default=None):
+    """Get the name associated with an element, either a name child or name attribute."""
+    name_elem = elem.find('name')
+    if name_elem is not None:
+        return name_elem.text
+    # Fallback if there is no child.
+    return elem.get('name', default)
+
+
+def getElemType(elem, default=None):
+    """Get the type associated with an element, either a type child or type attribute."""
+    type_elem = elem.find('type')
+    if type_elem is not None:
+        return type_elem.text
+    # Fallback if there is no child.
+    return elem.get('type', default)
+
+
+def findFirstWithPredicate(collection, pred):
+    """Return the first element that satisfies the predicate, or None if none exist.
+
+    NOTE: Some places where this is used might be better served by changing to a dictionary.
+    """
+    for elt in collection:
+        if pred(elt):
+            return elt
+    return None
+
+
+def findNamedElem(elems, name):
+    """Traverse a collection of elements with 'name' nodes or attributes, looking for and returning one with the right name.
+
+    NOTE: Many places where this is used might be better served by changing to a dictionary.
+    """
+    return findFirstWithPredicate(elems, lambda elem: getElemName(elem) == name)
+
+
+def findTypedElem(elems, typename):
+    """Traverse a collection of elements with 'type' nodes or attributes, looking for and returning one with the right typename.
+
+    NOTE: Many places where this is used might be better served by changing to a dictionary.
+    """
+    return findFirstWithPredicate(elems, lambda elem: getElemType(elem) == typename)
+
+
+def findNamedObject(collection, name):
+    """Traverse a collection of elements with 'name' attributes, looking for and returning one with the right name.
+
+    NOTE: Many places where this is used might be better served by changing to a dictionary.
+    """
+    return findFirstWithPredicate(collection, lambda elt: elt.name == name)