kicad/include/utf8.h

309 lines
9.4 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2013 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
* Copyright (C) 2013-2020 KiCad Developers, see AUTHORS.txt for contributors.
*
* @author Dick Hollenbeck
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#ifndef UTF8_H_
#define UTF8_H_
#include <string>
#include <wx/string.h>
#if defined(DEBUG)
#define UTF8_VERIFY // Might someday be a hidden cmake config option
#endif
/**
* Test a C string to see if it is UTF8 encoded.
*
* An ASCII string is a valid UTF8 string.
*/
bool IsUTF8( const char* aString );
#if defined(UTF8_VERIFY)
#define MAYBE_VERIFY_UTF8(x) wxASSERT( IsUTF8(x) )
#else
#define MAYBE_VERIFY_UTF8(x) // nothing
#endif
/**
* An 8 bit string that is assuredly encoded in UTF8, and supplies special conversion
* support to and from wxString, to and from std::string, and has non-mutating iteration
* over Unicode characters.
*
* I've been careful to supply only conversion facilities and not try and duplicate
* wxString() with many member functions. There are multiple ways to create text into
* a std::string without the need of too many member functions:
*
* - richio.h's StrPrintf().
* - std::ostringstream.
*
* Because this class uses no virtuals, it should be possible to cast any std::string
* into a UTF8 using this kind of cast: (UTF8 &) without construction or copying being
* the effect of the cast. Be sure the source std::string holds UTF8 encoded text before
* you do that.
*/
class UTF8
{
public:
UTF8( const wxString& o );
/// This is a constructor for which you could end up with
/// non-UTF8 encoding, but that would be your fault.
UTF8( const char* txt ) :
m_s( txt )
{
MAYBE_VERIFY_UTF8( c_str() );
}
/// For use with _() function on wx 2.8.
/// BTW _() on wx >= 2.9 returns wxString, not wchar_t* like on 2.8.
UTF8( const wchar_t* txt );
UTF8( const std::string& o ) :
m_s( o )
{
MAYBE_VERIFY_UTF8( c_str() );
}
UTF8()
{
}
~UTF8() // Needed mainly to build python wrapper
{
}
// expose some std::string functions publicly, since base class must be private.
const char* c_str() const { return m_s.c_str(); }
bool empty() const { return m_s.empty(); }
std::string::size_type find( char c ) const { return m_s.find( c ); }
std::string::size_type find( char c, size_t s ) const { return m_s.find( c, s ); }
void clear() { m_s.clear(); }
std::string::size_type length() const { return m_s.length(); }
std::string::size_type size() const { return m_s.size(); }
int compare( const std::string& s ) const { return m_s.compare( s ); }
bool operator==( const UTF8& rhs ) const { return m_s == rhs.m_s; }
bool operator==( const std::string& rhs ) const { return m_s == rhs; }
bool operator==( const char* s ) const { return m_s == s; }
std::string::size_type find_first_of( const std::string& str,
std::string::size_type pos = 0 ) const
{
return m_s.find_first_of( str, pos );
}
UTF8& operator+=( const UTF8& str )
{
m_s += str.m_s;
MAYBE_VERIFY_UTF8( c_str() );
return *this;
}
UTF8& operator+=( char ch )
{
m_s.operator+=( ch );
MAYBE_VERIFY_UTF8( c_str() );
return *this;
}
UTF8& operator+=( const char* s )
{
m_s.operator+=( s );
MAYBE_VERIFY_UTF8( c_str() );
return *this;
}
/// Append a wide (unicode) char to the UTF8 string.
/// if this wide char is not a ASCII7 char, it will be added as a UTF8 multibyte seqence
/// @param w_ch is a UTF-16 value (can be a UTF-32 on Linux)
UTF8& operator+=( unsigned w_ch );
// std::string::npos is not constexpr, so we can't use it in an
// initializer.
static constexpr std::string::size_type npos = -1;
UTF8& operator=( const wxString& o );
UTF8& operator=( const std::string& o )
{
m_s = o;
MAYBE_VERIFY_UTF8( c_str() );
return *this;
}
UTF8& operator=( const char* s )
{
m_s = s;
MAYBE_VERIFY_UTF8( c_str() );
return *this;
}
UTF8& operator=( char c )
{
m_s = c;
MAYBE_VERIFY_UTF8( c_str() );
return *this;
}
// a substring of a UTF8 is not necessarily a UTF8 if a multibyte character
// was split, so return std::string not UTF8
std::string substr( size_t pos = 0, size_t len = npos ) const
{
return m_s.substr( pos, len );
}
operator const std::string& () const { return m_s; }
//operator std::string& () { return m_s; }
//operator std::string () const { return m_s; }
wxString wx_str() const;
operator wxString () const;
// "Read only" iterating over bytes is done with these, use the uni_iter to iterate
// over UTF8 (multi-byte) characters
std::string::const_iterator begin() const { return m_s.begin(); }
std::string::const_iterator end() const { return m_s.end(); }
#ifndef SWIG
/**
* uni_iter
* is a non-mutating iterator that walks through unicode code points in the UTF8 encoded
* string. The normal ++(), ++(int), ->(), and *() operators are all supported
* for read only access and some return an unsigned holding the unicode character
* appropriate for the respective operator.
*/
class uni_iter
{
public:
uni_iter() // Needed only to build python wrapper, not used outside the wrapper
{
it = NULL;
}
uni_iter( const uni_iter& o )
{
it = o.it;
}
/// pre-increment and return uni_iter at new position
const uni_iter& operator++()
{
it += uni_forward( it );
return *this;
}
/// post-increment and return uni_iter at initial position
uni_iter operator++( int )
{
uni_iter ret = *this;
it += uni_forward( it );
return ret;
}
/// return unicode at current position
unsigned operator->() const
{
unsigned result;
// grab the result, do not advance
uni_forward( it, &result );
return result;
}
/// return unicode at current position
unsigned operator*() const
{
unsigned result;
// grab the result, do not advance
uni_forward( it, &result );
return result;
}
uni_iter operator-( int aVal ) const { return uni_iter( (char*) it - aVal ); }
bool operator==( const uni_iter& other ) const { return it == other.it; }
bool operator!=( const uni_iter& other ) const { return it != other.it; }
/// Since the ++ operators advance more than one byte, this is your best
/// loop termination test, < end(), not == end().
bool operator< ( const uni_iter& other ) const { return it < other.it; }
bool operator<=( const uni_iter& other ) const { return it <= other.it; }
bool operator> ( const uni_iter& other ) const { return it > other.it; }
bool operator>=( const uni_iter& other ) const { return it >= other.it; }
private:
friend class UTF8;
const unsigned char* it;
// private constructor
uni_iter( const char* start ) :
it( (const unsigned char*) start )
{
}
};
/**
* Returns a @a uni_iter initialized to the start of "this" UTF8 byte sequence.
*/
uni_iter ubegin() const
{
return uni_iter( m_s.data() );
}
/**
* Return a @a uni_iter initialized to the end of "this" UTF8 byte sequence.
*/
uni_iter uend() const
{
return uni_iter( m_s.data() + m_s.size() );
}
/**
* Advance over a single UTF8 encoded multibyte character, capturing the Unicode character
* as it goes, and returning the number of bytes consumed.
*
* @param aSequence is the UTF8 byte sequence, must be aligned on start of character.
* @param aResult is where to put the unicode character, and may be NULL if no interest.
* @return the count of bytes consumed.
*/
static int uni_forward( const unsigned char* aSequence, unsigned* aResult = NULL );
#endif // SWIG
protected:
std::string m_s;
};
#endif // UTF8_H_