chromium/third_party/openscreen/src/util/string_util.h

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UTIL_STRING_UTIL_H_
#define UTIL_STRING_UTIL_H_

#include <algorithm>
#include <cstring>
#include <initializer_list>
#include <string>
#include <string_view>

// String query and manipulation utilities.
namespace openscreen::string_util {

namespace internal {

extern const unsigned char kPropertyBits[256];
extern const char kToLower[256];
extern const char kToUpper[256];

}  // namespace internal

// Determines whether the given character is an alphabetic character.
inline bool ascii_isalpha(unsigned char c) { … }

// Determines whether the given character can be represented as a decimal
// digit character (i.e. {0-9}).
inline bool ascii_isdigit(unsigned char c) { … }

// Determines whether the given character is printable, including spaces.
inline bool ascii_isprint(unsigned char c) { … }

// Determines whether the given character is a whitespace character (space,
// tab, vertical tab, formfeed, linefeed, or carriage return).
inline bool ascii_isspace(unsigned char c) { … }

inline char ascii_tolower(unsigned char c) { … }

// Converts s to lowercase.
void AsciiStrToLower(std::string& s);

// Creates a lowercase string from a given string_view.
std::string AsciiStrToLower(std::string_view s);

inline char ascii_toupper(unsigned char c) { … }

// Converts s to uppercase.
void AsciiStrToUpper(std::string& s);

// Creates a uppercase string from a given string_view.
std::string AsciiStrToUpper(std::string_view s);

// Returns whether a given string `text` begins with `prefix`.
//
// NOTE: Replace with std::{string,string_view}::starts_with() once C++20 is the
// default.
inline bool starts_with(std::string_view text, std::string_view prefix) { … }

// Returns whether a given string `text` ends with `suffix`.
//
// NOTE: Replace with std::{string,string_view}::ends_with() once C++20 is the
// default.
inline bool ends_with(std::string_view text, std::string_view suffix) { … }

// Returns whether given ASCII strings `piece1` and `piece2` are equal, ignoring
// case in the comparison.
bool EqualsIgnoreCase(std::string_view piece1, std::string_view piece2);

// Returns std::string_view with whitespace stripped from the beginning of the
// given string_view.
inline std::string_view StripLeadingAsciiWhitespace(std::string_view str) { … }

// Concatenates arguments into a single string.
[[nodiscard]] std::string StrCat(
    std::initializer_list<std::string_view> pieces);

}  // namespace openscreen::string_util

#endif  // UTIL_STRING_UTIL_H_