libcruft-util/json.cpp.rl

563 lines
12 KiB
Ragel

/*
* This file is part of libgim.
*
* libgim 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 3 of the License, or (at your option) any later
* version.
*
* libgim 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 libgim. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2010-2012 Danny Robson <danny@nerdcruft.net>
*/
#include "json.hpp"
#include "debug.hpp"
#include "io.hpp"
#include "maths.hpp"
#include <deque>
#include <stdexcept>
#include <cstdlib>
#include <algorithm>
#include <sstream>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
using namespace std;
using namespace util;
//
// Parsing
//
struct parse_context {
parse_context(json::node *_root):
root (_root),
value (NULL),
key (NULL),
start (NULL),
stop (NULL)
{ ; }
json::node *root,
*value,
*key;
const char *start,
*stop;
};
%%{
machine json;
## Record whether parsing was successful for future use
action success
{ __success = true; }
action failure {
__success = false;
/*std::cerr << std::endl
<< "Failure on: '" << fc << "' in level " << top << " at " << fpc - p
<< std::endl;
*/
}
action new_object { nodestack.push_back (parse_context(new json::object)); }
action new_array { nodestack.push_back (parse_context(new json::array)); }
action new_object_value {
check_hard (nodestack.back ().root->is_object ());
check (nodestack.back ().key);
check (nodestack.back ().value);
if (!nodestack.back ().key->is_string ())
throw parse_error ("object keys must be strings");
json::object *object = (json::object*)nodestack.back ().root;
object->insert (nodestack.back ().key->as_string (),
unique_ptr<json::node> (nodestack.back ().value));
nodestack.back ().key = NULL;
nodestack.back ().value = NULL;
}
action new_array_value {
check_hard (nodestack.back ().root->is_array ());
check (nodestack.back ().value);
json::array *array = (json::array *)nodestack.back ().root;
array->insert (unique_ptr<json::node> (nodestack.back ().value));
nodestack.back ().value = NULL;
}
action new_string {
check_hard (!nodestack.empty ());
check (!nodestack.back ().value);
std::string value (std::string (nodestack.back ().start,
nodestack.back ().stop));
nodestack.back ().value = new json::string(value);
}
action new_boolean {
check_hard (!nodestack.empty ());
check (!nodestack.back ().value);
throw parse_error ("unable to parse boolean");
}
action new_number {
check_hard (!nodestack.empty ());
check (!nodestack.back ().value);
errno = 0;
double value = strtod (nodestack.back ().start, NULL);
if (errno)
throw parse_error ("unable to parse number");
nodestack.back ().value = new json::number (value);
}
action new_null {
check_hard (!nodestack.empty ());
check (!nodestack.back ().value);
nodestack.back().value = new json::null ();
}
action new_object_key {
check_hard (!nodestack.empty ());
check_hard (nodestack.back ().root->is_object ());
check (nodestack.back ().value);
check (!nodestack.back ().key);
nodestack.back ().key = nodestack.back ().value;
nodestack.back ().value = NULL;
}
prepush {
fsmstack.push_back (0);
}
postpop {
fsmstack.pop_back ();
__root = nodestack.back ().root;
if (nodestack.size () > 1)
(nodestack.rbegin () + 1)->value = nodestack.back ().root;
nodestack.pop_back ();
}
variable stack fsmstack;
alphtype char;
## numerical
exp = [eE]('-' | '+')? digit+;
frac = '.' digit+;
int = '-'? [1-9]? digit+;
number = int ( frac
| exp
| frac exp)?;
## textual
char =
any - (cntrl | '\"' | '\\')
| '\\\"'
| '\\\\'
| '\\/'
| '\\b'
| '\\f'
| '\\n'
| '\\r'
| '\\t'
| '\\u' xdigit{4};
string = ('"'
char* >{ nodestack.back ().start = fpc; }
%{ nodestack.back ().stop = fpc; })
'"'
@new_string;
## other
boolean =
'true' @{ nodestack.back ().value = new json::boolean ( true); }
| 'false' @{ nodestack.back ().value = new json::boolean (false); };
## components
object = '{' @{ fhold; fcall _object; } '}';
array = '[' @{ fhold; fcall _array; } ']';
value =
string
| boolean
| number >{ nodestack.back ().start = fpc; } %{ nodestack.back ().stop = fpc; } %new_number
| object
| array
| 'null' %new_null;
## compound data types
_array := ('[' @new_array
space* ((value %new_array_value space* ',' space*)* value %new_array_value space*)?
']')
$!failure
@{ fhold; fret; };
pair = string %new_object_key space* ':' space* value %new_object_value;
_object := ('{' @new_object
space* ((pair space* ',' space*)* pair space*)?
'}')
$!failure
@{ fhold; fret; };
json := (space* object space*)
$!failure
%success
>{ __success = false; };
write data;
}%%
//
// External support
//
template <>
bool
is_integer (const json::number &node) {
return is_integer (node.native ());
}
template <>
bool
is_integer (const json::node &node) {
return node.is_number () &&
is_integer (node.as_number ());
}
//
// Node
//
std::unique_ptr<json::node>
json::parse (const boost::filesystem::path &path)
{ return parse ((const char *)slurp (path)); }
std::unique_ptr<json::node>
json::parse (const std::string &path)
{ return parse (path.c_str (), path.c_str () + path.size ()); }
std::unique_ptr<json::node>
json::parse (const char *start,
const char *stop) {
bool __success = true;
json::node *__root = NULL;
size_t top = 0;
int cs;
deque <int> fsmstack;
deque <parse_context> nodestack;
const char *p = start,
*pe = stop,
*eof = stop;
%%write init;
%%write exec;
if (!__success)
throw parse_error ("unable to parse json");
//__root->print (cout) << endl;
check (*__root == *__root);
return std::unique_ptr<json::node> (__root);
}
std::unique_ptr<json::node>
json::parse (const char *start)
{ return parse (start, start + strlen (start)); }
void
json::write (const json::node &node, std::ostream &os)
{ node.write (os); }
//
// Type conversion
//
const json::object&
json::node::as_object (void) const
{ throw type_error ("node is not an object"); }
const json::array&
json::node::as_array (void) const
{ throw type_error ("node is not an array"); }
const json::string&
json::node::as_string (void) const
{ throw type_error ("node is not a string"); }
const json::number&
json::node::as_number (void) const
{ throw type_error ("node is not a number"); }
const json::boolean&
json::node::as_boolean (void) const
{ throw type_error ("node is not a boolean"); }
const json::null&
json::node::as_null (void) const
{ throw type_error ("node is not a null"); }
//
// Global operatoers
//
bool
json::node::operator!= (const node &rhs) const
{ return !(*this == rhs); }
bool json::node::operator==(const char *rhs) const {
try {
return as_string ().native () == rhs;
} catch (const json::type_error&) {
return false;
}
}
const json::node&
json::node::operator[] (const std::string &key) const
{ return as_object ()[key]; }
const json::node&
json::node::operator[] (unsigned int idx) const
{ return as_array()[idx]; }
//
// Object
//
json::object::~object ()
{ ; }
bool
json::object::operator ==(const json::object &rhs) const {
for (auto i = rhs.m_values.begin (), j = m_values.begin ();
i != rhs.m_values.end () && j != m_values.end ();
++i, ++j)
{
if (i->first != j->first)
return false;
if ((*i->second) != (*j->second))
return false;
}
return true;
}
void
json::object::insert (const std::string &_key, unique_ptr<json::node> &&value)
{ m_values[_key] = move(value); }
const json::node&
json::object::operator[](const std::string &key) const {
auto value = m_values.find (key);
if (value == m_values.end ()) {
ostringstream ss;
ss << "no key: " << key;
throw json::error (ss.str());
}
return *value->second;
}
bool
json::object::has (const std::string &key) const {
return m_values.find (key) != m_values.end ();
}
void
json::object::clear (void)
{ m_values.clear (); }
void
json::object::erase (const std::string &key) {
auto pos = m_values.find (key);
if (pos == m_values.end ())
throw json::error ("erasing invalid key");
m_values.erase (key);
}
json::object::const_iterator
json::object::begin (void) const
{ return m_values.begin (); }
json::object::const_iterator
json::object::end (void) const
{ return m_values.end (); }
std::ostream&
json::object::write (std::ostream &os) const {
os << "{\n";
{
indenter raii(os);
for (auto i = m_values.begin (); i != m_values.end ();) {
os << '"' << i->first << "\" : " << *i->second;
if (++i != m_values.end ())
os << ",\n";
}
}
os << "\n}";
return os;
}
//
// Array
//
json::array::~array()
{ ; }
void
json::array::insert (unique_ptr<json::node> &&_value)
{ m_values.push_back (move (_value)); }
bool
json::array::operator ==(const json::array &rhs) const {
for (auto i = rhs.m_values.begin (), j = m_values.begin ();
i != rhs.m_values.end () && j != m_values.end ();
++i, ++j)
{ if ((**i) != (**j)) return false; }
return true;
}
std::ostream&
json::array::write (std::ostream &os) const {
os << "[\n";
{
indenter raii(os);
for (auto i = m_values.begin (); i != m_values.end (); ++i) {
(*i)->write (os);
if (i != m_values.end () - 1)
os << ",\n";
}
}
os << "\n]";
return os;
}
//
// String
//
std::ostream&
json::string::write (std::ostream &os) const {
os << '"' << m_value << '"';
return os;
}
bool
json::string::operator ==(const json::string &rhs) const
{ return rhs.m_value == m_value; }
bool
json::string::operator ==(const char *rhs) const
{ return rhs == m_value; }
//
// Number
//
std::ostream&
json::number::write (std::ostream &os) const {
os << m_value;
return os;
}
bool
json::number::operator ==(const json::number &rhs) const
{ return almost_equal (rhs.m_value, m_value); }
//
// Boolean
//
std::ostream&
json::boolean::write (std::ostream &os) const {
os << (m_value ? "true" : "false");
return os;
}
bool
json::boolean::operator ==(const json::boolean &rhs) const
{ return rhs.m_value == m_value; }
//
// Null
//
std::ostream&
json::null::write (std::ostream &os) const {
os << "null";
return os;
}
ostream&
operator <<(ostream &os, const json::node &n)
{ return n.write (os); }