src/json/json_spirit_reader_template.h
#ifndef JSON_SPIRIT_READER_TEMPLATE
#define JSON_SPIRIT_READER_TEMPLATE
// Copyright John W. Wilkinson 2007 - 2009.
// Distributed under the MIT License, see accompanying file LICENSE.txt
// json spirit version 4.03
#include "json_spirit_value.h"
#include "json_spirit_error_position.h"
//#define BOOST_SPIRIT_THREADSAFE // uncomment for multithreaded use, requires linking to boost.thread
#include <boost/bind.hpp>
#include <boost/function.hpp>
#include <boost/version.hpp>
#if BOOST_VERSION >= 103800
#include <boost/spirit/include/classic_core.hpp>
#include <boost/spirit/include/classic_confix.hpp>
#include <boost/spirit/include/classic_escape_char.hpp>
#include <boost/spirit/include/classic_multi_pass.hpp>
#include <boost/spirit/include/classic_position_iterator.hpp>
#define spirit_namespace boost::spirit::classic
#else
#include <boost/spirit/core.hpp>
#include <boost/spirit/utility/confix.hpp>
#include <boost/spirit/utility/escape_char.hpp>
#include <boost/spirit/iterator/multi_pass.hpp>
#include <boost/spirit/iterator/position_iterator.hpp>
#define spirit_namespace boost::spirit
#endif
namespace json_spirit
{
const spirit_namespace::int_parser < int64_t > int64_p = spirit_namespace::int_parser < int64_t >();
const spirit_namespace::uint_parser< uint64_t > uint64_p = spirit_namespace::uint_parser< uint64_t >();
template< class Iter_type >
bool is_eq( Iter_type first, Iter_type last, const char* c_str )
{
for( Iter_type i = first; i != last; ++i, ++c_str )
{
if( *c_str == 0 ) return false;
if( *i != *c_str ) return false;
}
return true;
}
template< class Char_type >
Char_type hex_to_num( const Char_type c )
{
if( ( c >= '0' ) && ( c <= '9' ) ) return c - '0';
if( ( c >= 'a' ) && ( c <= 'f' ) ) return c - 'a' + 10;
if( ( c >= 'A' ) && ( c <= 'F' ) ) return c - 'A' + 10;
return 0;
}
template< class Char_type, class Iter_type >
Char_type hex_str_to_char( Iter_type& begin )
{
const Char_type c1( *( ++begin ) );
const Char_type c2( *( ++begin ) );
return ( hex_to_num( c1 ) << 4 ) + hex_to_num( c2 );
}
template< class Char_type, class Iter_type >
Char_type unicode_str_to_char( Iter_type& begin )
{
const Char_type c1( *( ++begin ) );
const Char_type c2( *( ++begin ) );
const Char_type c3( *( ++begin ) );
const Char_type c4( *( ++begin ) );
return ( hex_to_num( c1 ) << 12 ) +
( hex_to_num( c2 ) << 8 ) +
( hex_to_num( c3 ) << 4 ) +
hex_to_num( c4 );
}
template< class String_type >
void append_esc_char_and_incr_iter( String_type& s,
typename String_type::const_iterator& begin,
typename String_type::const_iterator end )
{
typedef typename String_type::value_type Char_type;
const Char_type c2( *begin );
switch( c2 )
{
case 't': s += '\t'; break;
case 'b': s += '\b'; break;
case 'f': s += '\f'; break;
case 'n': s += '\n'; break;
case 'r': s += '\r'; break;
case '\\': s += '\\'; break;
case '/': s += '/'; break;
case '"': s += '"'; break;
case 'x':
{
if( end - begin >= 3 ) // expecting "xHH..."
{
s += hex_str_to_char< Char_type >( begin );
}
break;
}
case 'u':
{
if( end - begin >= 5 ) // expecting "uHHHH..."
{
s += unicode_str_to_char< Char_type >( begin );
}
break;
}
}
}
template< class String_type >
String_type substitute_esc_chars( typename String_type::const_iterator begin,
typename String_type::const_iterator end )
{
typedef typename String_type::const_iterator Iter_type;
if( end - begin < 2 ) return String_type( begin, end );
String_type result;
result.reserve( end - begin );
const Iter_type end_minus_1( end - 1 );
Iter_type substr_start = begin;
Iter_type i = begin;
for( ; i < end_minus_1; ++i )
{
if( *i == '\\' )
{
result.append( substr_start, i );
++i; // skip the '\'
append_esc_char_and_incr_iter( result, i, end );
substr_start = i + 1;
}
}
result.append( substr_start, end );
return result;
}
template< class String_type >
String_type get_str_( typename String_type::const_iterator begin,
typename String_type::const_iterator end )
{
assert( end - begin >= 2 );
typedef typename String_type::const_iterator Iter_type;
Iter_type str_without_quotes( ++begin );
Iter_type end_without_quotes( --end );
return substitute_esc_chars< String_type >( str_without_quotes, end_without_quotes );
}
inline std::string get_str( std::string::const_iterator begin, std::string::const_iterator end )
{
return get_str_< std::string >( begin, end );
}
inline std::wstring get_str( std::wstring::const_iterator begin, std::wstring::const_iterator end )
{
return get_str_< std::wstring >( begin, end );
}
template< class String_type, class Iter_type >
String_type get_str( Iter_type begin, Iter_type end )
{
const String_type tmp( begin, end ); // convert multipass iterators to string iterators
return get_str( tmp.begin(), tmp.end() );
}
// this class's methods get called by the spirit parse resulting
// in the creation of a JSON object or array
//
// NB Iter_type could be a std::string iterator, wstring iterator, a position iterator or a multipass iterator
//
template< class Value_type, class Iter_type >
class Semantic_actions
{
public:
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;
Semantic_actions( Value_type& value )
: value_( value )
, current_p_( 0 )
{
}
void begin_obj( Char_type c )
{
assert( c == '{' );
begin_compound< Object_type >();
}
void end_obj( Char_type c )
{
assert( c == '}' );
end_compound();
}
void begin_array( Char_type c )
{
assert( c == '[' );
begin_compound< Array_type >();
}
void end_array( Char_type c )
{
assert( c == ']' );
end_compound();
}
void new_name( Iter_type begin, Iter_type end )
{
assert( current_p_->type() == obj_type );
name_ = get_str< String_type >( begin, end );
}
void new_str( Iter_type begin, Iter_type end )
{
add_to_current( get_str< String_type >( begin, end ) );
}
void new_true( Iter_type begin, Iter_type end )
{
assert( is_eq( begin, end, "true" ) );
add_to_current( true );
}
void new_false( Iter_type begin, Iter_type end )
{
assert( is_eq( begin, end, "false" ) );
add_to_current( false );
}
void new_null( Iter_type begin, Iter_type end )
{
assert( is_eq( begin, end, "null" ) );
add_to_current( Value_type() );
}
void new_int( int64_t i )
{
add_to_current( i );
}
void new_uint64( uint64_t ui )
{
add_to_current( ui );
}
void new_real( double d )
{
add_to_current( d );
}
private:
Semantic_actions& operator=( const Semantic_actions& );
// to prevent "assignment operator could not be generated" warning
Value_type* add_first( const Value_type& value )
{
assert( current_p_ == 0 );
value_ = value;
current_p_ = &value_;
return current_p_;
}
template< class Array_or_obj >
void begin_compound()
{
if( current_p_ == 0 )
{
add_first( Array_or_obj() );
}
else
{
stack_.push_back( current_p_ );
Array_or_obj new_array_or_obj; // avoid copy by building new array or object in place
current_p_ = add_to_current( new_array_or_obj );
}
}
void end_compound()
{
if( current_p_ != &value_ )
{
current_p_ = stack_.back();
stack_.pop_back();
}
}
Value_type* add_to_current( const Value_type& value )
{
if( current_p_ == 0 )
{
return add_first( value );
}
else if( current_p_->type() == array_type )
{
current_p_->get_array().push_back( value );
return ¤t_p_->get_array().back();
}
assert( current_p_->type() == obj_type );
return &Config_type::add( current_p_->get_obj(), name_, value );
}
Value_type& value_; // this is the object or array that is being created
Value_type* current_p_; // the child object or array that is currently being constructed
std::vector< Value_type* > stack_; // previous child objects and arrays
String_type name_; // of current name/value pair
};
template< typename Iter_type >
void throw_error( spirit_namespace::position_iterator< Iter_type > i, const std::string& reason )
{
throw Error_position( i.get_position().line, i.get_position().column, reason );
}
template< typename Iter_type >
void throw_error( Iter_type i, const std::string& reason )
{
throw reason;
}
// the spirit grammer
//
template< class Value_type, class Iter_type >
class Json_grammer : public spirit_namespace::grammar< Json_grammer< Value_type, Iter_type > >
{
public:
typedef Semantic_actions< Value_type, Iter_type > Semantic_actions_t;
Json_grammer( Semantic_actions_t& semantic_actions )
: actions_( semantic_actions )
{
}
static void throw_not_value( Iter_type begin, Iter_type end )
{
throw_error( begin, "not a value" );
}
static void throw_not_array( Iter_type begin, Iter_type end )
{
throw_error( begin, "not an array" );
}
static void throw_not_object( Iter_type begin, Iter_type end )
{
throw_error( begin, "not an object" );
}
static void throw_not_pair( Iter_type begin, Iter_type end )
{
throw_error( begin, "not a pair" );
}
static void throw_not_colon( Iter_type begin, Iter_type end )
{
throw_error( begin, "no colon in pair" );
}
static void throw_not_string( Iter_type begin, Iter_type end )
{
throw_error( begin, "not a string" );
}
template< typename ScannerT >
class definition
{
public:
definition( const Json_grammer& self )
{
using namespace spirit_namespace;
typedef typename Value_type::String_type::value_type Char_type;
// first we convert the semantic action class methods to functors with the
// parameter signature expected by spirit
typedef boost::function< void( Char_type ) > Char_action;
typedef boost::function< void( Iter_type, Iter_type ) > Str_action;
typedef boost::function< void( double ) > Real_action;
typedef boost::function< void( int64_t ) > Int_action;
typedef boost::function< void( uint64_t ) > Uint64_action;
Char_action begin_obj ( boost::bind( &Semantic_actions_t::begin_obj, &self.actions_, _1 ) );
Char_action end_obj ( boost::bind( &Semantic_actions_t::end_obj, &self.actions_, _1 ) );
Char_action begin_array( boost::bind( &Semantic_actions_t::begin_array, &self.actions_, _1 ) );
Char_action end_array ( boost::bind( &Semantic_actions_t::end_array, &self.actions_, _1 ) );
Str_action new_name ( boost::bind( &Semantic_actions_t::new_name, &self.actions_, _1, _2 ) );
Str_action new_str ( boost::bind( &Semantic_actions_t::new_str, &self.actions_, _1, _2 ) );
Str_action new_true ( boost::bind( &Semantic_actions_t::new_true, &self.actions_, _1, _2 ) );
Str_action new_false ( boost::bind( &Semantic_actions_t::new_false, &self.actions_, _1, _2 ) );
Str_action new_null ( boost::bind( &Semantic_actions_t::new_null, &self.actions_, _1, _2 ) );
Real_action new_real ( boost::bind( &Semantic_actions_t::new_real, &self.actions_, _1 ) );
Int_action new_int ( boost::bind( &Semantic_actions_t::new_int, &self.actions_, _1 ) );
Uint64_action new_uint64 ( boost::bind( &Semantic_actions_t::new_uint64, &self.actions_, _1 ) );
// actual grammer
json_
= value_ | eps_p[ &throw_not_value ]
;
value_
= string_[ new_str ]
| number_
| object_
| array_
| str_p( "true" ) [ new_true ]
| str_p( "false" )[ new_false ]
| str_p( "null" ) [ new_null ]
;
object_
= ch_p('{')[ begin_obj ]
>> !members_
>> ( ch_p('}')[ end_obj ] | eps_p[ &throw_not_object ] )
;
members_
= pair_ >> *( ',' >> pair_ )
;
pair_
= string_[ new_name ]
>> ( ':' | eps_p[ &throw_not_colon ] )
>> ( value_ | eps_p[ &throw_not_value ] )
;
array_
= ch_p('[')[ begin_array ]
>> !elements_
>> ( ch_p(']')[ end_array ] | eps_p[ &throw_not_array ] )
;
elements_
= value_ >> *( ',' >> value_ )
;
string_
= lexeme_d // this causes white space inside a string to be retained
[
confix_p
(
'"',
*lex_escape_ch_p,
'"'
)
]
;
number_
= strict_real_p[ new_real ]
| int64_p [ new_int ]
| uint64_p [ new_uint64 ]
;
}
spirit_namespace::rule< ScannerT > json_, object_, members_, pair_, array_, elements_, value_, string_, number_;
const spirit_namespace::rule< ScannerT >& start() const { return json_; }
};
private:
Json_grammer& operator=( const Json_grammer& ); // to prevent "assignment operator could not be generated" warning
Semantic_actions_t& actions_;
};
template< class Iter_type, class Value_type >
Iter_type read_range_or_throw( Iter_type begin, Iter_type end, Value_type& value )
{
Semantic_actions< Value_type, Iter_type > semantic_actions( value );
const spirit_namespace::parse_info< Iter_type > info =
spirit_namespace::parse( begin, end,
Json_grammer< Value_type, Iter_type >( semantic_actions ),
spirit_namespace::space_p );
if( !info.hit )
{
assert( false ); // in theory exception should already have been thrown
throw_error( info.stop, "error" );
}
return info.stop;
}
template< class Iter_type, class Value_type >
void add_posn_iter_and_read_range_or_throw( Iter_type begin, Iter_type end, Value_type& value )
{
typedef spirit_namespace::position_iterator< Iter_type > Posn_iter_t;
const Posn_iter_t posn_begin( begin, end );
const Posn_iter_t posn_end( end, end );
read_range_or_throw( posn_begin, posn_end, value );
}
template< class Iter_type, class Value_type >
bool read_range( Iter_type& begin, Iter_type end, Value_type& value )
{
try
{
begin = read_range_or_throw( begin, end, value );
return true;
}
catch( ... )
{
return false;
}
}
template< class String_type, class Value_type >
void read_string_or_throw( const String_type& s, Value_type& value )
{
add_posn_iter_and_read_range_or_throw( s.begin(), s.end(), value );
}
template< class String_type, class Value_type >
bool read_string( const String_type& s, Value_type& value )
{
typename String_type::const_iterator begin = s.begin();
return read_range( begin, s.end(), value );
}
template< class Istream_type >
struct Multi_pass_iters
{
typedef typename Istream_type::char_type Char_type;
typedef std::istream_iterator< Char_type, Char_type > istream_iter;
typedef spirit_namespace::multi_pass< istream_iter > Mp_iter;
Multi_pass_iters( Istream_type& is )
{
is.unsetf( std::ios::skipws );
begin_ = spirit_namespace::make_multi_pass( istream_iter( is ) );
end_ = spirit_namespace::make_multi_pass( istream_iter() );
}
Mp_iter begin_;
Mp_iter end_;
};
template< class Istream_type, class Value_type >
bool read_stream( Istream_type& is, Value_type& value )
{
Multi_pass_iters< Istream_type > mp_iters( is );
return read_range( mp_iters.begin_, mp_iters.end_, value );
}
template< class Istream_type, class Value_type >
void read_stream_or_throw( Istream_type& is, Value_type& value )
{
const Multi_pass_iters< Istream_type > mp_iters( is );
add_posn_iter_and_read_range_or_throw( mp_iters.begin_, mp_iters.end_, value );
}
}
#endif