json.cpp

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/*******************************************************************\
 
Module:
 
Author: Daniel Kroening, kroening@kroening.com
 
\*******************************************************************/
 
#include "json.h"
 
#include "structured_data.h"
 
#include <algorithm>
#include <ostream>
 
const jsont jsont::null_json_object(jsont::kindt::J_NULL);
 
void jsont::escape_string(const std::string &src, std::ostream &out)
{
  for(const auto &ch : src)
  {
    switch(ch)
    {
    case '\\':
    case '"':
      out << '\\';
      out << ch;
      break;
 
    case '\b':
      out << "\\b";
      break;
 
    case '\f':
      out << "\\f";
      break;
 
    case '\n':
      out << "\\n";
      break;
 
    case '\r':
      out << "\\r";
      break;
 
    case '\t':
      out << "\\t";
      break;
 
    default:
      out << ch;
    }
  }
}
 
void jsont::output_rec(std::ostream &out, unsigned indent) const
{
  switch(kind)
  {
  case kindt::J_STRING:
    out << '"';
    escape_string(value, out);
    out << '"';
    break;
 
  case kindt::J_NUMBER:
    out << value;
    break;
 
  case kindt::J_OBJECT:
    out << '{';
    output_object(out, object, indent);
    if(!object.empty())
    {
      out << '\n';
      out << std::string(indent*2, ' ');
    }
    out << '}';
    break;
 
  case kindt::J_ARRAY:
    out << '[';
 
    if(array.empty())
      out << ' ';
    else
    {
      for(arrayt::const_iterator a_it=array.begin();
          a_it!=array.end();
          a_it++)
      {
        if(a_it!=array.begin())
          out << ',';
 
        if(a_it->is_object())
        {
          out << '\n';
          out << std::string((indent+1)*2, ' ');
        }
        else
          out << ' ';
 
        a_it->output_rec(out, indent+1);
      }
 
      if(array.back().is_object())
        out << '\n' << std::string(indent*2, ' ');
      else
        out << ' ';
    }
 
    out << ']';
    break;
 
  case kindt::J_TRUE: out << "true"; break;
 
  case kindt::J_FALSE: out << "false"; break;
 
  case kindt::J_NULL: out << "null"; break;
  }
}
 
void jsont::output_object(
  std::ostream &out,
  const objectt &object,
  unsigned indent)
{
  for(objectt::const_iterator o_it = object.begin(); o_it != object.end();
      o_it++)
  {
    if(o_it != object.begin())
      out << ',';
 
    // A JSON object always starts with an opening brace,
    // after which we put a newline.
    out << '\n';
 
    out << std::string((indent + 1) * 2, ' ');
 
    jsont::output_key(out, o_it->first);
    o_it->second.output_rec(out, indent + 1);
  }
}
 
void jsont::output_key(std::ostream &out, const std::string &key)
{
  out << '"';
  jsont::escape_string(key, out);
  out << "\": ";
}
 
void jsont::swap(jsont &other)
{
  std::swap(other.kind, kind);
  other.array.swap(array);
  other.object.swap(object);
  other.value.swap(value);
}
 
bool operator==(const jsont &left, const jsont &right)
{
  if(left.kind != right.kind)
    return false;
  switch(left.kind)
  {
  case jsont::kindt::J_NULL:
    return true;
  case jsont::kindt::J_TRUE:
    return true;
  case jsont::kindt::J_FALSE:
    return true;
  case jsont::kindt::J_NUMBER:
    return left.value == right.value;
  case jsont::kindt::J_STRING:
    return left.value == right.value;
  case jsont::kindt::J_ARRAY:
  {
    const auto &left_array = static_cast<const json_arrayt &>(left);
    const auto &right_array = static_cast<const json_arrayt &>(right);
    return left_array.size() == right_array.size() &&
           std::equal(
             left_array.begin(), left_array.end(), right_array.begin());
  }
  case jsont::kindt::J_OBJECT:
  {
    const auto &left_object = static_cast<const json_objectt &>(left);
    const auto &right_object = static_cast<const json_objectt &>(right);
    if(left_object.size() != left_object.size())
      return false;
    return std::all_of(
      left_object.begin(),
      left_object.end(),
      [&](const std::pair<std::string, jsont> &pair) {
        return right_object[pair.first] == pair.second;
      });
  }
  }
  UNREACHABLE;
}
 
jsont json_node(const structured_data_entryt &entry)
{
  if(entry.is_leaf())
    return entry.leaf_object();
  else
  {
    json_objectt result;
    for(const auto &sub_entry : entry.children())
    {
      result[sub_entry.first.camel_case()] = json_node(sub_entry.second);
    }
    return std::move(result);
  }
}
 
jsont to_json(const structured_datat &data)
{
  if(data.data().size() == 0)
    return jsont{};
 
  json_objectt result;
  for(const auto &sub_entry : data.data())
  {
    result[sub_entry.first.camel_case()] = json_node(sub_entry.second);
  }
  return std::move(result);
}