73 lines
2.1 KiB
Python
73 lines
2.1 KiB
Python
# Copyright 2017 The Bazel Authors. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Skylib module containing functions that operate on collections."""
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def _after_each(separator, iterable):
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"""Inserts `separator` after each item in `iterable`.
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Args:
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separator: The value to insert after each item in `iterable`.
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iterable: The list into which to intersperse the separator.
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Returns:
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A new list with `separator` after each item in `iterable`.
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"""
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result = []
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for x in iterable:
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result.append(x)
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result.append(separator)
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return result
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def _before_each(separator, iterable):
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"""Inserts `separator` before each item in `iterable`.
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Args:
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separator: The value to insert before each item in `iterable`.
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iterable: The list into which to intersperse the separator.
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Returns:
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A new list with `separator` before each item in `iterable`.
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"""
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result = []
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for x in iterable:
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result.append(separator)
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result.append(x)
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return result
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def _uniq(iterable):
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"""Returns a list of unique elements in `iterable`.
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Requires all the elements to be hashable.
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Args:
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iterable: An iterable to filter.
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Returns:
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A new list with all unique elements from `iterable`.
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"""
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unique_elements = {element: None for element in iterable}
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# list() used here for python3 compatibility.
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# TODO(bazel-team): Remove when testing frameworks no longer require python compatibility.
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return list(unique_elements.keys())
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collections = struct(
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after_each = _after_each,
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before_each = _before_each,
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uniq = _uniq,
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)
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