utf8.h File Reference

Various UTF8 related helper functions. More...

#include <cstdint>
#include <string>

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Functions
std::string	convertUTF8ToLower (const std::string &input)
	Converts the input string into a lower case version, also taking into account non-ASCII characters that has a lower case variant.
std::string	convertUTF8ToUpper (const std::string &input)
	Converts the input string into a upper case version, also taking into account non-ASCII characters that has a upper case variant.
std::string	getUTF8CharAt (const std::string &input, size_t pos)
	Returns the UTF8 character found at byte position pos in the input string.
uint32_t	getUnicodeForUTF8CharAt (const std::string &input, size_t pos)
	Returns the 32bit Unicode value matching character at byte position pos in the UTF8 encoded input.
uint8_t	getUTF8CharNumBytes (char firstByte)
	Returns the number of bytes making up a single UTF8 character given the first byte in the sequence.
const char *	writeUTF8Char (TextStream &t, const char *s)
	Writes the UTF8 character pointed to by s to stream t and returns a pointer to the next character.
bool	lastUTF8CharIsMultibyte (const std::string &input)
	Returns true iff the last character in input is a multibyte character.
bool	isUTF8CharUpperCase (const std::string &input, size_t pos)
	Returns true iff the input string at byte position pos holds an upper case character.
int	isUTF8NonBreakableSpace (const char *input)
	Check if the first character pointed at by input is a non-breakable whitespace character.
bool	isUTF8PunctuationCharacter (uint32_t unicode)
	Check if the given Unicode character represents a punctuation character.
bool	transcodeCharacterStringToUTF8 (std::string &input, const char *inputEncoding)
	Recodes the input string from the given input encoding to UTF8.

Detailed Description

Various UTF8 related helper functions.

See https://en.wikipedia.org/wiki/UTF-8 for details on UTF8 encoding.

Definition in file utf8.h.

Function Documentation

convertUTF8ToLower()

std::string convertUTF8ToLower

(

const std::string &

input

)

Converts the input string into a lower case version, also taking into account non-ASCII characters that has a lower case variant.

Definition at line 188 of file utf8.cpp.

{
  return caseConvert(input,asciiToLower,convertUnicodeToLower);
}

References asciiToLower(), caseConvert(), and convertUnicodeToLower().

Referenced by SearchIndexInfo::add(), Index::addClassMemberNameToIndex(), Index::addFileMemberNameToIndex(), Index::addModuleMemberNameToIndex(), Index::addNamespaceMemberNameToIndex(), AnchorGenerator::generate(), DString::lower(), FileNameFn::searchKey(), SearchTerm::termEncoded(), and HtmlGenerator::writeLabel().

convertUTF8ToUpper()

std::string convertUTF8ToUpper

(

const std::string &

input

)

Converts the input string into a upper case version, also taking into account non-ASCII characters that has a upper case variant.

Definition at line 193 of file utf8.cpp.

{
  return caseConvert(input,asciiToUpper,convertUnicodeToUpper);
}

References asciiToUpper(), caseConvert(), and convertUnicodeToUpper().

Referenced by Translator::createNoun(), DString::upper(), and writeAlphabeticalClassList().

getUnicodeForUTF8CharAt()

uint32_t getUnicodeForUTF8CharAt	(	const std::string &	input,
		size_t	pos )

Returns the 32bit Unicode value matching character at byte position pos in the UTF8 encoded input.

Definition at line 136 of file utf8.cpp.

{
  std::string charS = getUTF8CharAt(input,pos);
  int len=0;
  return convertUTF8CharToUnicode(charS.c_str(),charS.length(),len);
}

References convertUTF8CharToUnicode(), and getUTF8CharAt().

Referenced by AnchorGenerator::generate().

getUTF8CharAt()

std::string getUTF8CharAt	(	const std::string &	input,
		size_t	pos )

Returns the UTF8 character found at byte position pos in the input string.

The resulting string can be a multi byte sequence.

Definition at line 128 of file utf8.cpp.

{
  if (input.length()<=pos) return std::string();
  int numBytes=getUTF8CharNumBytes(input[pos]);
  if (input.length()<pos+numBytes) return std::string();
  return input.substr(pos,numBytes);
}

References getUTF8CharNumBytes().

Referenced by SearchIndexInfo::add(), Index::addClassMemberNameToIndex(), Index::addFileMemberNameToIndex(), Index::addModuleMemberNameToIndex(), Index::addNamespaceMemberNameToIndex(), Translator::createNoun(), AnchorGenerator::generate(), getUnicodeForUTF8CharAt(), and writeAlphabeticalClassList().

getUTF8CharNumBytes()

uint8_t getUTF8CharNumBytes

(

char

firstByte

)

Returns the number of bytes making up a single UTF8 character given the first byte in the sequence.

Definition at line 24 of file utf8.cpp.

{
  uint8_t num=1;
  unsigned char uc = static_cast<unsigned char>(c);
  if (uc>=0x80u) // multibyte character
  {
    if ((uc&0xE0u)==0xC0u)
    {
      num=2; // 110x.xxxx: 2 byte character
    }
    if ((uc&0xF0u)==0xE0u)
    {
      num=3; // 1110.xxxx: 3 byte character
    }
    if ((uc&0xF8u)==0xF0u)
    {
      num=4; // 1111.0xxx: 4 byte character
    }
    if ((uc&0xFCu)==0xF8u)
    {
      num=5; // 1111.10xx: 5 byte character
    }
    if ((uc&0xFEu)==0xFCu)
    {
      num=6; // 1111.110x: 6 byte character
    }
  }
  return num;
}

Referenced by detab(), escapeCharsInString(), AnchorGenerator::generate(), getUTF8CharAt(), nextUTF8CharPosition(), updateColumnCount(), and writeUTF8Char().

isUTF8CharUpperCase()

bool isUTF8CharUpperCase	(	const std::string &	input,
		size_t	pos )

Returns true iff the input string at byte position pos holds an upper case character.

Definition at line 219 of file utf8.cpp.

{
  if (input.length()<=pos) return false;
  int len=0;
  // turn the UTF8 character at position pos into a unicode value
  uint32_t code = convertUTF8CharToUnicode(input.c_str()+pos,input.length()-pos,len);
  // check if the character can be converted to lower case, if so it was an upper case character
  return convertUnicodeToLower(code)!=nullptr;
}

References convertUnicodeToLower(), and convertUTF8CharToUnicode().

Referenced by DefinitionImpl::_setBriefDescription().

isUTF8NonBreakableSpace()

int isUTF8NonBreakableSpace

(

const char *

input

)

Check if the first character pointed at by input is a non-breakable whitespace character.

Returns the byte size of the character if there is match or 0 if not.

Definition at line 229 of file utf8.cpp.

{
  return (static_cast<unsigned char>(input[0])==0xC2 &&
          static_cast<unsigned char>(input[1])==0xA0) ? 2 : 0;
}

Referenced by detab().

isUTF8PunctuationCharacter()

bool isUTF8PunctuationCharacter

(

uint32_t

unicode

)

Check if the given Unicode character represents a punctuation character.

Definition at line 235 of file utf8.cpp.

{
  bool b = isPunctuationCharacter(unicode);
  return b;
}

References isPunctuationCharacter().

Referenced by AnchorGenerator::generate().

lastUTF8CharIsMultibyte()

bool lastUTF8CharIsMultibyte

(

const std::string &

input

)

Returns true iff the last character in input is a multibyte character.

Definition at line 213 of file utf8.cpp.

{
  // last byte is part of a multibyte UTF8 char if bit 8 is set and bit 7 is not
  return !input.empty() && (static_cast<unsigned char>(input[input.length()-1])&0xC0)==0x80;
}

Referenced by DefinitionImpl::_setBriefDescription().

transcodeCharacterStringToUTF8()

bool transcodeCharacterStringToUTF8	(	std::string &	input,
		const char *	inputEncoding )

Recodes the input string from the given input encoding to UTF8.

Returns true if successful, false otherwise.

Definition at line 241 of file utf8.cpp.

{
  const char *outputEncoding = "UTF-8";
  if (inputEncoding==nullptr || dstricmp(inputEncoding,outputEncoding)==0) return true;
  size_t inputSize=input.length();
  size_t outputSize=inputSize*4;
  DString output(outputSize, DString::ExplicitSize);
  void *cd = portable_iconv_open(outputEncoding,inputEncoding);
  if (cd==reinterpret_cast<void *>(-1))
  {
    return false;
  }
  bool ok=true;
  size_t iLeft=inputSize;
  size_t oLeft=outputSize;
  const char *inputPtr = input.data();
  char *outputPtr = output.rawData();
  if (!portable_iconv(cd, &inputPtr, &iLeft, &outputPtr, &oLeft))
  {
    outputSize-=static_cast<int>(oLeft);
    output.resize(outputSize);
    output.at(outputSize)='\0';
    // replace input
    input=output.str();
    //printf("iconv: input size=%d output size=%d\n[%s]\n",size,newSize,qPrint(srcBuf));
  }
  else
  {
    ok=false;
  }
  portable_iconv_close(cd);
  return ok;
}

References DString::at(), dstricmp(), DString::ExplicitSize, portable_iconv(), portable_iconv_close(), portable_iconv_open(), DString::rawData(), DString::resize(), and DString::str().

Referenced by LayoutDocManager::parse(), and readCodeFragment().

writeUTF8Char()

const char * writeUTF8Char	(	TextStream &	t,
		const char *	s )

Writes the UTF8 character pointed to by s to stream t and returns a pointer to the next character.

Definition at line 198 of file utf8.cpp.

{
  if (s==nullptr) return nullptr;
  uint8_t len = getUTF8CharNumBytes(*s);
  for (uint8_t i=0;i<len;i++)
  {
    if (s[i]==0) // detect premature end of string (due to invalid UTF8 char)
    {
      len=i;
    }
  }
  t.write(s,len);
  return s+len;
}

References getUTF8CharNumBytes(), and TextStream::write().

Referenced by HtmlCodeGenerator::codify(), ManCodeGenerator::codify(), RTFCodeGenerator::codify(), HtmlDocVisitor::operator()(), HtmlDocVisitor::writeObfuscatedMailAddress(), and writeXMLCodeString().