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