# Copyright (c) 2016 Cloudera, Inc. All rights reserved.
#
# 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.

# Common patterns that ought to be the same throughout the framework should be placed
# here.

import re

# http://www.cloudera.com/content/www/en-us/documentation/enterprise/latest/topics/impala_identifiers.html
VALID_IMPALA_IDENTIFIER_REGEX = re.compile(r'^[a-zA-Z][a-zA-Z0-9_]{,127}$')


def is_valid_impala_identifier(identifier):
  """Return True if identifier is a valid Impala identifier, False otherwise."""
  return VALID_IMPALA_IDENTIFIER_REGEX.match(identifier) is not None