MultiMC5/hacks/boost/property_tree/detail/json_parser_read.hpp
2013-01-22 05:56:12 +01:00

334 lines
11 KiB
C++

// ----------------------------------------------------------------------------
// Copyright (C) 2002-2006 Marcin Kalicinski
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// For more information, see www.boost.org
// ----------------------------------------------------------------------------
#ifndef BOOST_PROPERTY_TREE_DETAIL_JSON_PARSER_READ_HPP_INCLUDED
#define BOOST_PROPERTY_TREE_DETAIL_JSON_PARSER_READ_HPP_INCLUDED
//#define BOOST_SPIRIT_DEBUG
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/detail/ptree_utils.hpp>
#include <boost/property_tree/detail/json_parser_error.hpp>
#include <boost/spirit/include/classic.hpp>
#include <boost/limits.hpp>
#include <string>
#include <locale>
#include <istream>
#include <vector>
#include <algorithm>
namespace boost { namespace property_tree { namespace json_parser
{
///////////////////////////////////////////////////////////////////////
// Json parser context
template<class Ptree>
struct context
{
typedef typename Ptree::key_type::value_type Ch;
typedef std::basic_string<Ch> Str;
typedef typename std::vector<Ch>::iterator It;
Str string;
Str name;
Ptree root;
std::vector<Ptree *> stack;
struct a_object_s
{
context &c;
a_object_s(context &c): c(c) { }
void operator()(Ch) const
{
if (c.stack.empty())
c.stack.push_back(&c.root);
else
{
Ptree *parent = c.stack.back();
Ptree *child = &parent->push_back(std::make_pair(c.name, Ptree()))->second;
c.stack.push_back(child);
c.name.clear();
}
}
};
struct a_object_e
{
context &c;
a_object_e(context &c): c(c) { }
void operator()(Ch) const
{
BOOST_ASSERT(c.stack.size() >= 1);
c.stack.pop_back();
}
};
struct a_name
{
context &c;
a_name(context &c): c(c) { }
void operator()(It, It) const
{
c.name.swap(c.string);
c.string.clear();
}
};
struct a_string_val
{
context &c;
a_string_val(context &c): c(c) { }
void operator()(It, It) const
{
BOOST_ASSERT(c.stack.size() >= 1);
c.stack.back()->push_back(std::make_pair(c.name, Ptree(c.string)));
c.name.clear();
c.string.clear();
}
};
struct a_literal_val
{
context &c;
a_literal_val(context &c): c(c) { }
void operator()(It b, It e) const
{
BOOST_ASSERT(c.stack.size() >= 1);
c.stack.back()->push_back(std::make_pair(c.name,
Ptree(Str(b, e))));
c.name.clear();
c.string.clear();
}
};
struct a_char
{
context &c;
a_char(context &c): c(c) { }
void operator()(It b, It e) const
{
c.string += *b;
}
};
struct a_escape
{
context &c;
a_escape(context &c): c(c) { }
void operator()(Ch ch) const
{
switch (ch)
{
case Ch('\"'): c.string += Ch('\"'); break;
case Ch('\\'): c.string += Ch('\\'); break;
case Ch('/'): c.string += Ch('/'); break;
case Ch('b'): c.string += Ch('\b'); break;
case Ch('f'): c.string += Ch('\f'); break;
case Ch('n'): c.string += Ch('\n'); break;
case Ch('r'): c.string += Ch('\r'); break;
case Ch('t'): c.string += Ch('\t'); break;
default: BOOST_ASSERT(0);
}
}
};
struct a_unicode
{
context &c;
a_unicode(context &c): c(c) { }
void operator()(unsigned long u) const
{
//u = (std::min)(u, static_cast<unsigned long>((std::numeric_limits<Ch>::max)()));
c.string += Ch(u);
}
};
};
///////////////////////////////////////////////////////////////////////
// Json grammar
template<class Ptree>
struct json_grammar :
public boost::spirit::classic::grammar<json_grammar<Ptree> >
{
typedef context<Ptree> Context;
typedef typename Ptree::key_type::value_type Ch;
mutable Context c;
template<class Scanner>
struct definition
{
boost::spirit::classic::rule<Scanner>
root, object, member, array, item, value, string, number;
boost::spirit::classic::rule<
typename boost::spirit::classic::lexeme_scanner<Scanner>::type>
character, escape;
definition(const json_grammar &self)
{
using namespace boost::spirit::classic;
// There's a boost::assertion too, so another explicit using
// here:
using boost::spirit::classic::assertion;
// Assertions
assertion<std::string> expect_root("expected object or array");
assertion<std::string> expect_eoi("expected end of input");
assertion<std::string> expect_objclose("expected ',' or '}'");
assertion<std::string> expect_arrclose("expected ',' or ']'");
assertion<std::string> expect_name("expected object name");
assertion<std::string> expect_colon("expected ':'");
assertion<std::string> expect_value("expected value");
assertion<std::string> expect_escape("invalid escape sequence");
// JSON grammar rules
root
= expect_root(object | array)
>> expect_eoi(end_p)
;
object
= ch_p('{')[typename Context::a_object_s(self.c)]
>> (ch_p('}')[typename Context::a_object_e(self.c)]
| (list_p(member, ch_p(','))
>> expect_objclose(ch_p('}')[typename Context::a_object_e(self.c)])
)
)
;
member
= expect_name(string[typename Context::a_name(self.c)])
>> expect_colon(ch_p(':'))
>> expect_value(value)
;
array
= ch_p('[')[typename Context::a_object_s(self.c)]
>> (ch_p(']')[typename Context::a_object_e(self.c)]
| (list_p(item, ch_p(','))
>> expect_arrclose(ch_p(']')[typename Context::a_object_e(self.c)])
)
)
;
item
= expect_value(value)
;
value
= string[typename Context::a_string_val(self.c)]
| (number | str_p("true") | "false" | "null")[typename Context::a_literal_val(self.c)]
| object
| array
;
number
= !ch_p("-") >>
(ch_p("0") | (range_p(Ch('1'), Ch('9')) >> *digit_p)) >>
!(ch_p(".") >> +digit_p) >>
!(chset_p(detail::widen<Ch>("eE").c_str()) >>
!chset_p(detail::widen<Ch>("-+").c_str()) >>
+digit_p)
;
string
= +(lexeme_d[confix_p('\"', *character, '\"')])
;
character
= (anychar_p - "\\" - "\"")
[typename Context::a_char(self.c)]
| ch_p("\\") >> expect_escape(escape)
;
escape
= chset_p(detail::widen<Ch>("\"\\/bfnrt").c_str())
[typename Context::a_escape(self.c)]
| 'u' >> uint_parser<unsigned long, 16, 4, 4>()
[typename Context::a_unicode(self.c)]
;
// Debug
BOOST_SPIRIT_DEBUG_RULE(root);
BOOST_SPIRIT_DEBUG_RULE(object);
BOOST_SPIRIT_DEBUG_RULE(member);
BOOST_SPIRIT_DEBUG_RULE(array);
BOOST_SPIRIT_DEBUG_RULE(item);
BOOST_SPIRIT_DEBUG_RULE(value);
BOOST_SPIRIT_DEBUG_RULE(string);
BOOST_SPIRIT_DEBUG_RULE(number);
BOOST_SPIRIT_DEBUG_RULE(escape);
BOOST_SPIRIT_DEBUG_RULE(character);
}
const boost::spirit::classic::rule<Scanner> &start() const
{
return root;
}
};
};
template<class It, class Ch>
unsigned long count_lines(It begin, It end)
{
return static_cast<unsigned long>(std::count(begin, end, Ch('\n')) + 1);
}
template<class Ptree>
void read_json_internal(std::basic_istream<typename Ptree::key_type::value_type> &stream,
Ptree &pt,
const std::string &filename)
{
using namespace boost::spirit::classic;
typedef typename Ptree::key_type::value_type Ch;
typedef typename std::vector<Ch>::iterator It;
// Load data into vector
std::vector<Ch> v(std::istreambuf_iterator<Ch>(stream.rdbuf()),
std::istreambuf_iterator<Ch>());
if (!stream.good())
BOOST_PROPERTY_TREE_THROW(json_parser_error("read error", filename, 0));
// Prepare grammar
json_grammar<Ptree> g;
// Parse
try
{
parse_info<It> pi = parse(v.begin(), v.end(), g,
space_p | comment_p("//") | comment_p("/*", "*/"));
if (!pi.hit || !pi.full)
BOOST_PROPERTY_TREE_THROW((parser_error<std::string, It>(v.begin(), "syntax error")));
}
catch (parser_error<std::string, It> &e)
{
BOOST_PROPERTY_TREE_THROW(json_parser_error(e.descriptor, filename, count_lines<It, Ch>(v.begin(), e.where)));
}
// Swap grammar context root and pt
pt.swap(g.c.root);
}
} } }
#endif