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/**
* Copyright 2010 Google Inc.
*
* 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.
*/
// Routines to do manipulation of Unicode characters or text
//
// The StructurallyValid routines accept buffers of arbitrary bytes.
// For CoerceToStructurallyValid(), the input buffer and output buffers may
// point to exactly the same memory.
//
// In all other cases, the UTF-8 string must be structurally valid and
// have all codepoints in the range U+0000 to U+D7FF or U+E000 to U+10FFFF.
// Debug builds take a fatal error for invalid UTF-8 input.
// The input and output buffers may not overlap at all.
//
// The char32 routines are here only for convenience; they convert to UTF-8
// internally and use the UTF-8 routines.
#ifndef UTIL_UTF8_UNILIB_H__
#define UTIL_UTF8_UNILIB_H__
#include <string>
#include "phonenumbers/base/basictypes.h"
namespace UniLib {
// Returns true unless a surrogate code point
inline bool IsValidCodepoint(char32 c) {
// In the range [0, 0xD800) or [0xE000, 0x10FFFF]
return (static_cast<uint32>(c) < 0xD800)
|| (c >= 0xE000 && c <= 0x10FFFF);
}
// Table of UTF-8 character lengths, based on first byte
static const unsigned char kUTF8LenTbl[256] = {
1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,
2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,
3,3,3,3,3,3,3,3, 3,3,3,3,3,3,3,3, 4,4,4,4,4,4,4,4, 4,4,4,4,4,4,4,4
};
// Return length of a single UTF-8 source character
inline int OneCharLen(const char* src) {
return kUTF8LenTbl[*reinterpret_cast<const uint8*>(src)];
}
// Return length of a single UTF-8 source character
inline int OneCharLen(const uint8* src) {
return kUTF8LenTbl[*src];
}
// Return true if this byte is a trailing UTF-8 byte (10xx xxxx)
inline bool IsTrailByte(char x) {
// return (x & 0xC0) == 0x80;
// Since trail bytes are always in [0x80, 0xBF], we can optimize:
return static_cast<signed char>(x) < -0x40;
}
// Returns the length in bytes of the prefix of src that is all
// interchange valid UTF-8
int SpanInterchangeValid(const char* src, int byte_length);
inline int SpanInterchangeValid(const std::string& src) {
return SpanInterchangeValid(src.data(), src.size());
}
// Returns true if the source is all interchange valid UTF-8
// "Interchange valid" is a stronger than structurally valid --
// no C0 or C1 control codes (other than CR LF HT FF) and no non-characters.
inline bool IsInterchangeValid(const char* src, int byte_length) {
return (byte_length == SpanInterchangeValid(src, byte_length));
}
inline bool IsInterchangeValid(const std::string& src) {
return IsInterchangeValid(src.data(), src.size());
}
} // namespace UniLib
#endif // UTIL_UTF8_PUBLIC_UNILIB_H_
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