| // Copyright 2016 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef SRC_LIB_FXL_STRINGS_UTF_CODECS_H_ |
| #define SRC_LIB_FXL_STRINGS_UTF_CODECS_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <string> |
| #include <string_view> |
| |
| #include "src/lib/fxl/fxl_export.h" |
| |
| namespace fxl { |
| |
| inline bool IsValidCodepoint(uint32_t code_point) { |
| // Excludes the surrogate code points ([0xD800, 0xDFFF]) and |
| // codepoints larger than 0x10FFFF (the highest codepoint allowed). |
| // Non-characters and unassigned codepoints are allowed. |
| return code_point < 0xD800u || (code_point >= 0xE000u && code_point <= 0x10FFFFu); |
| } |
| |
| inline bool IsValidCharacter(uint32_t code_point) { |
| // Excludes non-characters (U+FDD0..U+FDEF, and all codepoints ending in |
| // 0xFFFE or 0xFFFF) from the set of valid code points. |
| return code_point < 0xD800u || (code_point >= 0xE000u && code_point < 0xFDD0u) || |
| (code_point > 0xFDEFu && code_point <= 0x10FFFFu && (code_point & 0xFFFEu) != 0xFFFEu); |
| } |
| |
| bool IsStringUTF8(std::string_view str); |
| |
| // ReadUnicodeCharacter -------------------------------------------------------- |
| |
| // Reads a UTF-8 stream, placing the next code point into the given output |
| // |*code_point|. |src| represents the entire string to read, and |*char_index| |
| // is the character offset within the string to start reading at. |*char_index| |
| // will be updated to index the last character read, such that incrementing it |
| // (as in a for loop) will take the reader to the next character. |
| // |
| // Returns true on success. On false, |*code_point| will be invalid. |
| bool ReadUnicodeCharacter(const char* src, size_t src_len, size_t* char_index, |
| uint32_t* code_point_out); |
| |
| // WriteUnicodeCharacter ------------------------------------------------------- |
| |
| // Appends a UTF-8 character to the given 8-bit string. Returns the number of |
| // bytes written. |
| size_t WriteUnicodeCharacter(uint32_t code_point, std::string* output); |
| |
| } // namespace fxl |
| |
| #endif // SRC_LIB_FXL_STRINGS_UTF_CODECS_H_ |