checked.h

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// Copyright 2006 Nemanja Trifunovic

/*
Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
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Software, and to permit third-parties to whom the Software is furnished to
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The copyright notices in the Software and this entire statement, including
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must be included in all copies of the Software, in whole or in part, and
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
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*/


#ifndef UTF8_FOR_CPP_CHECKED_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
#define UTF8_FOR_CPP_CHECKED_H_2675DCD0_9480_4c0c_B92A_CC14C027B731

#include "core.h"
#include <stdexcept>

namespace utf8
{
 // Base for the exceptions that may be thrown from the library
 class exception : public ::std::exception {
 };

 // Exceptions that may be thrown from the library functions.
 class invalid_code_point : public exception {
 uint32_t cp;
 public:
 invalid_code_point(uint32_t cp) : cp(cp) {}
 virtual const char* what() const throw() { return "Invalid code point"; }
 uint32_t code_point() const {return cp;}
 };

 class invalid_utf8 : public exception {
 uint8_t u8;
 public:
 invalid_utf8 (uint8_t u) : u8(u) {}
 virtual const char* what() const throw() { return "Invalid UTF-8"; }
 uint8_t utf8_octet() const {return u8;}
 };

 class invalid_utf16 : public exception {
 uint16_t u16;
 public:
 invalid_utf16 (uint16_t u) : u16(u) {}
 virtual const char* what() const throw() { return "Invalid UTF-16"; }
 uint16_t utf16_word() const {return u16;}
 };

 class not_enough_room : public exception {
 public:
 virtual const char* what() const throw() { return "Not enough space"; }
 };


 template <typename octet_iterator>
 octet_iterator append(uint32_t cp, octet_iterator result)
 {
 if (!utf8::internal::is_code_point_valid(cp))
 throw invalid_code_point(cp);

 if (cp < 0x80) // one octet
 *(result++) = static_cast<uint8_t>(cp);
 else if (cp < 0x800) { // two octets
 *(result++) = static_cast<uint8_t>((cp >> 6) | 0xc0);
 *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
 }
 else if (cp < 0x10000) { // three octets
 *(result++) = static_cast<uint8_t>((cp >> 12) | 0xe0);
 *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f) | 0x80);
 *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
 }
 else { // four octets
 *(result++) = static_cast<uint8_t>((cp >> 18) | 0xf0);
 *(result++) = static_cast<uint8_t>(((cp >> 12) & 0x3f) | 0x80);
 *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f) | 0x80);
 *(result++) = static_cast<uint8_t>((cp & 0x3f) | 0x80);
 }
 return result;
 }

 template <typename octet_iterator, typename output_iterator>
 output_iterator replace_invalid(octet_iterator start, octet_iterator end, output_iterator out, uint32_t replacement)
 {
 while (start != end) {
 octet_iterator sequence_start = start;
 internal::utf_error err_code = utf8::internal::validate_next(start, end);
 switch (err_code) {
 case internal::UTF8_OK :
 for (octet_iterator it = sequence_start; it != start; ++it)
 *out++ = *it;
 break;
 case internal::NOT_ENOUGH_ROOM:
 throw not_enough_room();
 case internal::INVALID_LEAD:
 out = utf8::append (replacement, out);
 ++start;
 break;
 case internal::INCOMPLETE_SEQUENCE:
 case internal::OVERLONG_SEQUENCE:
 case internal::INVALID_CODE_POINT:
 out = utf8::append (replacement, out);
 ++start;
 // just one replacement mark for the sequence
 while (start != end && utf8::internal::is_trail(*start))
 ++start;
 break;
 }
 }
 return out;
 }

 template <typename octet_iterator, typename output_iterator>
 inline output_iterator replace_invalid(octet_iterator start, octet_iterator end, output_iterator out)
 {
 static const uint32_t replacement_marker = utf8::internal::mask16(0xfffd);
 return utf8::replace_invalid(start, end, out, replacement_marker);
 }

 template <typename octet_iterator>
 uint32_t next(octet_iterator& it, octet_iterator end)
 {
 uint32_t cp = 0;
 internal::utf_error err_code = utf8::internal::validate_next(it, end, cp);
 switch (err_code) {
 case internal::UTF8_OK :
 break;
 case internal::NOT_ENOUGH_ROOM :
 throw not_enough_room();
 case internal::INVALID_LEAD :
 case internal::INCOMPLETE_SEQUENCE :
 case internal::OVERLONG_SEQUENCE :
 throw invalid_utf8(*it);
 case internal::INVALID_CODE_POINT :
 throw invalid_code_point(cp);
 }
 return cp;
 }

 template <typename octet_iterator>
 uint32_t peek_next(octet_iterator it, octet_iterator end)
 {
 return utf8::next(it, end);
 }

 template <typename octet_iterator>
 uint32_t prior(octet_iterator& it, octet_iterator start)
 {
 // can't do much if it == start
 if (it == start)
 throw not_enough_room();

 octet_iterator end = it;
 // Go back until we hit either a lead octet or start
 while (utf8::internal::is_trail(*(--it)))
 if (it == start)
 throw invalid_utf8(*it); // error - no lead byte in the sequence
 return utf8::peek_next(it, end);
 }

 template <typename octet_iterator>
 uint32_t previous(octet_iterator& it, octet_iterator pass_start)
 {
 octet_iterator end = it;
 while (utf8::internal::is_trail(*(--it)))
 if (it == pass_start)
 throw invalid_utf8(*it); // error - no lead byte in the sequence
 octet_iterator temp = it;
 return utf8::next(temp, end);
 }

 template <typename octet_iterator, typename distance_type>
 void advance (octet_iterator& it, distance_type n, octet_iterator end)
 {
 for (distance_type i = 0; i < n; ++i)
 utf8::next(it, end);
 }

 template <typename octet_iterator>
 typename std::iterator_traits<octet_iterator>::difference_type
 distance (octet_iterator first, octet_iterator last)
 {
 typename std::iterator_traits<octet_iterator>::difference_type dist;
 for (dist = 0; first < last; ++dist)
 utf8::next(first, last);
 return dist;
 }

 template <typename u16bit_iterator, typename octet_iterator>
 octet_iterator utf16to8 (u16bit_iterator start, u16bit_iterator end, octet_iterator result)
 {
 while (start != end) {
 uint32_t cp = utf8::internal::mask16(*start++);
 // Take care of surrogate pairs first
 if (utf8::internal::is_lead_surrogate(cp)) {
 if (start != end) {
 uint32_t trail_surrogate = utf8::internal::mask16(*start++);
 if (utf8::internal::is_trail_surrogate(trail_surrogate))
 cp = (cp << 10) + trail_surrogate + internal::SURROGATE_OFFSET;
 else
 throw invalid_utf16(static_cast<uint16_t>(trail_surrogate));
 }
 else
 throw invalid_utf16(static_cast<uint16_t>(cp));

 }
 // Lone trail surrogate
 else if (utf8::internal::is_trail_surrogate(cp))
 throw invalid_utf16(static_cast<uint16_t>(cp));

 result = utf8::append(cp, result);
 }
 return result;
 }

 template <typename u16bit_iterator, typename octet_iterator>
 u16bit_iterator utf8to16 (octet_iterator start, octet_iterator end, u16bit_iterator result)
 {
 while (start != end) {
 uint32_t cp = utf8::next(start, end);
 if (cp > 0xffff) { //make a surrogate pair
 *result++ = static_cast<uint16_t>((cp >> 10) + internal::LEAD_OFFSET);
 *result++ = static_cast<uint16_t>((cp & 0x3ff) + internal::TRAIL_SURROGATE_MIN);
 }
 else
 *result++ = static_cast<uint16_t>(cp);
 }
 return result;
 }

 template <typename octet_iterator, typename u32bit_iterator>
 octet_iterator utf32to8 (u32bit_iterator start, u32bit_iterator end, octet_iterator result)
 {
 while (start != end)
 result = utf8::append(*(start++), result);

 return result;
 }

 template <typename octet_iterator, typename u32bit_iterator>
 u32bit_iterator utf8to32 (octet_iterator start, octet_iterator end, u32bit_iterator result)
 {
 while (start != end)
 (*result++) = utf8::next(start, end);

 return result;
 }

 // The iterator class
 template <typename octet_iterator>
 class iterator : public std::iterator <std::bidirectional_iterator_tag, uint32_t> {
 octet_iterator it;
 octet_iterator range_start;
 octet_iterator range_end;
 public:
 iterator () {}
 explicit iterator (const octet_iterator& octet_it,
 const octet_iterator& range_start,
 const octet_iterator& range_end) :
 it(octet_it), range_start(range_start), range_end(range_end)
 {
 if (it < range_start || it > range_end)
 throw std::out_of_range("Invalid utf-8 iterator position");
 }
 // the default "big three" are OK
 octet_iterator base () const { return it; }
 uint32_t operator * () const
 {
 octet_iterator temp = it;
 return utf8::next(temp, range_end);
 }
 bool operator == (const iterator& rhs) const
 {
 if (range_start != rhs.range_start || range_end != rhs.range_end)
 throw std::logic_error("Comparing utf-8 iterators defined with different ranges");
 return (it == rhs.it);
 }
 bool operator != (const iterator& rhs) const
 {
 return !(operator == (rhs));
 }
 iterator& operator ++ ()
 {
 utf8::next(it, range_end);
 return *this;
 }
 iterator operator ++ (int)
 {
 iterator temp = *this;
 utf8::next(it, range_end);
 return temp;
 }
 iterator& operator -- ()
 {
 utf8::prior(it, range_start);
 return *this;
 }
 iterator operator -- (int)
 {
 iterator temp = *this;
 utf8::prior(it, range_start);
 return temp;
 }
 }; // class iterator

} // namespace utf8

#endif //header guard