#ifndef JSON_SPIRIT_WRITER_TEMPLATE
#define JSON_SPIRIT_WRITER_TEMPLATE
// Copyright John W. Wilkinson 2007 - 2011
// Distributed under the MIT License, see accompanying file LICENSE.txt
// json spirit version 4.04
#include "json_spirit_value.h"
#include <cassert>
#include <sstream>
#include <iomanip>
#include <boost/io/ios_state.hpp>
namespace json_spirit
{
enum Output_options{ pretty_print = 0x01, // Add whitespace to format the output nicely.
raw_utf8 = 0x02, // This prevents non-printable characters from being escapted using "\uNNNN" notation.
// Note, this is an extension to the JSON standard. It disables the escaping of
// non-printable characters allowing UTF-8 sequences held in 8 bit char strings
// to pass through unaltered.
remove_trailing_zeros = 0x04
// outputs e.g. "1.200000000000000" as "1.2"
};
inline char to_hex_char( unsigned int c )
{
assert( c <= 0xF );
const char ch = static_cast< char >( c );
if( ch < 10 ) return '0' + ch;
return 'A' - 10 + ch;
}
template< class String_type >
String_type non_printable_to_string( unsigned int c )
{
typedef typename String_type::value_type Char_type;
String_type result( 6, '\\' );
result[1] = 'u';
result[ 5 ] = to_hex_char( c & 0x000F ); c >>= 4;
result[ 4 ] = to_hex_char( c & 0x000F ); c >>= 4;
result[ 3 ] = to_hex_char( c & 0x000F ); c >>= 4;
result[ 2 ] = to_hex_char( c & 0x000F );
return result;
}
template< typename Char_type, class String_type >
bool add_esc_char( Char_type c, String_type& s )
{
switch( c )
{
case '"': s += to_str< String_type >( "\\\"" ); return true;
case '\\': s += to_str< String_type >( "\\\\" ); return true;
case '\b': s += to_str< String_type >( "\\b" ); return true;
case '\f': s += to_str< String_type >( "\\f" ); return true;
case '\n': s += to_str< String_type >( "\\n" ); return true;
case '\r': s += to_str< String_type >( "\\r" ); return true;
case '\t': s += to_str< String_type >( "\\t" ); return true;
}
return false;
}
template< class String_type >
String_type add_esc_chars( const String_type& s, bool raw_utf8 )
{
typedef typename String_type::const_iterator Iter_type;
typedef typename String_type::value_type Char_type;
String_type result;
const Iter_type end( s.end() );
for( Iter_type i = s.begin(); i != end; ++i )
{
const Char_type c( *i );
if( add_esc_char( c, result ) ) continue;
if( raw_utf8 )
{
result += c;
}
else
{
const wint_t unsigned_c( ( c >= 0 ) ? c : 256 + c );
if( iswprint( unsigned_c ) )
{
result += c;
}
else
{
result += non_printable_to_string< String_type >( unsigned_c );
}
}
}
return result;
}
template< class Ostream >
void append_double( Ostream& os, const double d, const int precision )
{
os << std::showpoint << std::setprecision( precision ) << d;
}
template< class String_type >
void erase_and_extract_exponent( String_type& str, String_type& exp )
{
const typename String_type::size_type exp_start= str.find( 'e' );
if( exp_start != String_type::npos )
{
exp = str.substr( exp_start );
str.erase( exp_start );
}
}
template< class String_type >
typename String_type::size_type find_first_non_zero( const String_type& str )
{
typename String_type::size_type result = str.size() - 1;
for( ; result != 0; --result )
{
if( str[ result ] != '0' )
{
break;
}
}
return result;
}
template< class String_type >
void remove_trailing( String_type& str )
{
String_type exp;
erase_and_extract_exponent( str, exp );
const typename String_type::size_type first_non_zero = find_first_non_zero( str );
if( first_non_zero != 0 )
{
str.erase( first_non_zero + 1 );
}
str += exp;
}
// this class generates the JSON text,
// it keeps track of the indentation level etc.
//
template< class Value_type, class Ostream_type >
class Generator
{
typedef typename Value_type::Config_type Config_type;
typedef typename Config_type::String_type String_type;
typedef typename Config_type::Object_type Object_type;
typedef typename Config_type::Array_type Array_type;
typedef typename String_type::value_type Char_type;
typedef typename Object_type::value_type Obj_member_type;
public:
Generator( const Value_type& value, Ostream_type& os, unsigned int options )
: os_( os )
, indentation_level_( 0 )
, pretty_( ( options & pretty_print ) != 0 )
, raw_utf8_( ( options & raw_utf8 ) != 0 )
, remove_trailing_zeros_( ( options & remove_trailing_zeros ) != 0 )
, ios_saver_( os )
{
output( value );
}
private:
void output( const Value_type& value )
{
switch( value.type() )
{
case obj_type: output( value.get_obj() ); break;
case array_type: output( value.get_array() ); break;
case str_type: output( value.get_str() ); break;
case bool_type: output( value.get_bool() ); break;
case real_type: output( value.get_real() ); break;
case int_type: output_int( value ); break;
case null_type: os_ << "null"; break;
default: assert( false );
}
}
void output( const Object_type& obj )
{
output_array_or_obj( obj, '{', '}' );
}
void output( const Array_type& arr )
{
output_array_or_obj( arr, '[', ']' );
}
void output( const Obj_member_type& member )
{
output( Config_type::get_name( member ) ); space();
os_ << ':'; space();
output( Config_type::get_value( member ) );
}
void output_int( const Value_type& value )
{
if( value.is_uint64() )
{
os_ << value.get_uint64();
}
else
{
os_ << value.get_int64();
}
}
void output( const String_type& s )
{
os_ << '"' << add_esc_chars( s, raw_utf8_ ) << '"';
}
void output( bool b )
{
os_ << to_str< String_type >( b ? "true" : "false" );
}
void output( double d )
{
if( remove_trailing_zeros_ )
{
std::basic_ostringstream< Char_type > os;
append_double( os, d, 16 ); // note precision is 16 so that we get some trailing space that we can remove,
// otherwise, 0.1234 gets converted to "0.12399999..."
String_type str = os.str();
remove_trailing( str );
os_ << str;
}
else
{
append_double( os_, d, 17 );
}
}
template< class T >
void output_array_or_obj( const T& t, Char_type start_char, Char_type end_char )
{
os_ << start_char; new_line();
++indentation_level_;
for( typename T::const_iterator i = t.begin(); i != t.end(); ++i )
{
indent(); output( *i );
typename T::const_iterator next = i;
if( ++next != t.end())
{
os_ << ',';
}
new_line();
}
--indentation_level_;
indent(); os_ << end_char;
}
void indent()
{
if( !pretty_ ) return;
for( int i = 0; i < indentation_level_; ++i )
{
os_ << " ";
}
}
void space()
{
if( pretty_ ) os_ << ' ';
}
void new_line()
{
if( pretty_ ) os_ << '\n';
}
Generator& operator=( const Generator& ); // to prevent "assignment operator could not be generated" warning
Ostream_type& os_;
int indentation_level_;
bool pretty_;
bool raw_utf8_;
bool remove_trailing_zeros_;
boost::io::basic_ios_all_saver< Char_type > ios_saver_; // so that ostream state is reset after control is returned to the caller
};
// writes JSON Value to a stream, e.g.
//
// write_stream( value, os, pretty_print );
//
template< class Value_type, class Ostream_type >
void write_stream( const Value_type& value, Ostream_type& os, unsigned int options = 0 )
{
os << std::dec;
Generator< Value_type, Ostream_type >( value, os, options );
}
// writes JSON Value to a stream, e.g.
//
// const string json_str = write( value, pretty_print );
//
template< class Value_type >
typename Value_type::String_type write_string( const Value_type& value, unsigned int options = 0 )
{
typedef typename Value_type::String_type::value_type Char_type;
std::basic_ostringstream< Char_type > os;
write_stream( value, os, options );
return os.str();
}
}
#endif
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