94 lines
3.1 KiB
C++
94 lines
3.1 KiB
C++
//
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// Copyright 2017 The Abseil Authors.
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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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// https://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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//
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// -----------------------------------------------------------------------------
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// File: strip.h
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// -----------------------------------------------------------------------------
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//
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// This file contains various functions for stripping substrings from a string.
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#ifndef ABSL_STRINGS_STRIP_H_
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#define ABSL_STRINGS_STRIP_H_
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#include <cstddef>
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#include <string>
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#include "absl/base/macros.h"
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#include "absl/strings/ascii.h"
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#include "absl/strings/match.h"
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#include "absl/strings/string_view.h"
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namespace absl {
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ABSL_NAMESPACE_BEGIN
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// ConsumePrefix()
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//
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// Strips the `expected` prefix, if found, from the start of `str`.
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// If the operation succeeded, `true` is returned. If not, `false`
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// is returned and `str` is not modified.
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//
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// Example:
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//
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// absl::string_view input("abc");
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// EXPECT_TRUE(absl::ConsumePrefix(&input, "a"));
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// EXPECT_EQ(input, "bc");
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inline bool ConsumePrefix(absl::string_view* str, absl::string_view expected) {
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if (!absl::StartsWith(*str, expected)) return false;
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str->remove_prefix(expected.size());
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return true;
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}
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// ConsumeSuffix()
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//
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// Strips the `expected` suffix, if found, from the end of `str`.
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// If the operation succeeded, `true` is returned. If not, `false`
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// is returned and `str` is not modified.
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//
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// Example:
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//
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// absl::string_view input("abcdef");
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// EXPECT_TRUE(absl::ConsumeSuffix(&input, "def"));
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// EXPECT_EQ(input, "abc");
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inline bool ConsumeSuffix(absl::string_view* str, absl::string_view expected) {
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if (!absl::EndsWith(*str, expected)) return false;
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str->remove_suffix(expected.size());
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return true;
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}
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// StripPrefix()
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//
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// Returns a view into the input string `str` with the given `prefix` removed,
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// but leaving the original string intact. If the prefix does not match at the
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// start of the string, returns the original string instead.
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ABSL_MUST_USE_RESULT inline absl::string_view StripPrefix(
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absl::string_view str, absl::string_view prefix) {
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if (absl::StartsWith(str, prefix)) str.remove_prefix(prefix.size());
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return str;
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}
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// StripSuffix()
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//
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// Returns a view into the input string `str` with the given `suffix` removed,
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// but leaving the original string intact. If the suffix does not match at the
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// end of the string, returns the original string instead.
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ABSL_MUST_USE_RESULT inline absl::string_view StripSuffix(
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absl::string_view str, absl::string_view suffix) {
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if (absl::EndsWith(str, suffix)) str.remove_suffix(suffix.size());
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return str;
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}
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ABSL_NAMESPACE_END
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} // namespace absl
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#endif // ABSL_STRINGS_STRIP_H_
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