// // 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 // // 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. // // ----------------------------------------------------------------------------- // 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_