| /* |
| * |
| * Copyright (c) 2023 Project CHIP Authors |
| * All rights reserved. |
| * |
| * 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. |
| */ |
| #pragma once |
| |
| #include <lib/support/Span.h> |
| |
| namespace chip { |
| namespace Utf8 { |
| |
| /** |
| * Validate that the given span looks like a valid UTF-8 string |
| * |
| * UTF-8 encoding described at |
| * https://www.unicode.org/versions/Unicode12.0.0/UnicodeStandard-12.0.pdf |
| * but TLDR is: |
| * |
| * | Scalar Value | First B | Second B | Third B | Fourth B | |
| * +----------------------------+----------+----------+----------+----------+ |
| * | 00000000 0xxxxxxx | 0xxxxxxx | | | | |
| * | 00000yyy yyxxxxxx | 110yyyyy | 10xxxxxx | | | |
| * | zzzzyyyy yyxxxxxx | 1110zzzz | 10yyyyyy | 10xxxxxx | | |
| * | 000uuuuu zzzzyyyy yyxxxxxx | 11110uuu | 10uuzzzz | 10yyyyyy | 10xxxxxx | |
| * +----------------------------+----------+----------+----------+----------+ |
| * |
| * Further more, individual encodings must be minimally encoded, so |
| * 0xC0 is not a valid first byte( 1100_0000 10xxxxxx could have been encoded |
| * as one-byte) |
| */ |
| bool IsValid(CharSpan span); |
| |
| } // namespace Utf8 |
| } // namespace chip |
