AnimTestbed/3rdparty/imgui-node-editor/crude_json.cpp

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// Crude implementation of JSON value object and parser.
//
// VERSION 0.1
//
// LICENSE
// This software is dual-licensed to the public domain and under the following
// license: you are granted a perpetual, irrevocable license to copy, modify,
// publish, and distribute this file as you see fit.
//
// CREDITS
// Written by Michal Cichon
# include "crude_json.h"
# include <iomanip>
# include <limits>
# include <cstdlib>
# include <clocale>
# include <cmath>
# include <cstring>
# if CRUDE_JSON_IO
# include <stdio.h>
# include <memory>
# endif
namespace crude_json {
value::value(value&& other)
: m_Type(other.m_Type)
{
switch (m_Type)
{
case type_t::object: construct(m_Storage, std::move( *object_ptr(other.m_Storage))); break;
case type_t::array: construct(m_Storage, std::move( *array_ptr(other.m_Storage))); break;
case type_t::string: construct(m_Storage, std::move( *string_ptr(other.m_Storage))); break;
case type_t::boolean: construct(m_Storage, std::move(*boolean_ptr(other.m_Storage))); break;
case type_t::number: construct(m_Storage, std::move( *number_ptr(other.m_Storage))); break;
default: break;
}
destruct(other.m_Storage, other.m_Type);
other.m_Type = type_t::null;
}
value::value(const value& other)
: m_Type(other.m_Type)
{
switch (m_Type)
{
case type_t::object: construct(m_Storage, *object_ptr(other.m_Storage)); break;
case type_t::array: construct(m_Storage, *array_ptr(other.m_Storage)); break;
case type_t::string: construct(m_Storage, *string_ptr(other.m_Storage)); break;
case type_t::boolean: construct(m_Storage, *boolean_ptr(other.m_Storage)); break;
case type_t::number: construct(m_Storage, *number_ptr(other.m_Storage)); break;
default: break;
}
}
value& value::operator[](size_t index)
{
if (is_null())
m_Type = construct(m_Storage, type_t::array);
if (is_array())
{
auto& v = *array_ptr(m_Storage);
if (index >= v.size())
v.insert(v.end(), index - v.size() + 1, value());
return v[index];
}
CRUDE_ASSERT(false && "operator[] on unsupported type");
std::terminate();
}
const value& value::operator[](size_t index) const
{
if (is_array())
return (*array_ptr(m_Storage))[index];
CRUDE_ASSERT(false && "operator[] on unsupported type");
std::terminate();
}
value& value::operator[](const string& key)
{
if (is_null())
m_Type = construct(m_Storage, type_t::object);
if (is_object())
return (*object_ptr(m_Storage))[key];
CRUDE_ASSERT(false && "operator[] on unsupported type");
std::terminate();
}
const value& value::operator[](const string& key) const
{
if (is_object())
{
auto& o = *object_ptr(m_Storage);
auto it = o.find(key);
CRUDE_ASSERT(it != o.end());
return it->second;
}
CRUDE_ASSERT(false && "operator[] on unsupported type");
std::terminate();
}
bool value::contains(const string& key) const
{
if (is_object())
{
auto& o = *object_ptr(m_Storage);
auto it = o.find(key);
return it != o.end();
}
return false;
}
void value::push_back(const value& value)
{
if (is_null())
m_Type = construct(m_Storage, type_t::array);
if (is_array())
{
auto& v = *array_ptr(m_Storage);
v.push_back(value);
}
else
{
CRUDE_ASSERT(false && "operator[] on unsupported type");
std::terminate();
}
}
void value::push_back(value&& value)
{
if (is_null())
m_Type = construct(m_Storage, type_t::array);
if (is_array())
{
auto& v = *array_ptr(m_Storage);
v.push_back(std::move(value));
}
else
{
CRUDE_ASSERT(false && "operator[] on unsupported type");
std::terminate();
}
}
size_t value::erase(const string& key)
{
if (!is_object())
return 0;
auto& o = *object_ptr(m_Storage);
auto it = o.find(key);
if (it == o.end())
return 0;
o.erase(it);
return 1;
}
void value::swap(value& other)
{
using std::swap;
if (m_Type == other.m_Type)
{
switch (m_Type)
{
case type_t::object: swap(*object_ptr(m_Storage), *object_ptr(other.m_Storage)); break;
case type_t::array: swap(*array_ptr(m_Storage), *array_ptr(other.m_Storage)); break;
case type_t::string: swap(*string_ptr(m_Storage), *string_ptr(other.m_Storage)); break;
case type_t::boolean: swap(*boolean_ptr(m_Storage), *boolean_ptr(other.m_Storage)); break;
case type_t::number: swap(*number_ptr(m_Storage), *number_ptr(other.m_Storage)); break;
default: break;
}
}
else
{
value tmp(std::move(other));
other.~value();
new (&other) value(std::move(*this));
this->~value();
new (this) value(std::move(tmp));
}
}
string value::dump(const int indent, const char indent_char) const
{
dump_context_t context(indent, indent_char);
context.out.precision(std::numeric_limits<double>::max_digits10 + 1);
context.out << std::defaultfloat;
dump(context, 0);
return context.out.str();
}
void value::dump_context_t::write_indent(int level)
{
if (indent <= 0 || level == 0)
return;
out.fill(indent_char);
out.width(indent * level);
out << indent_char;
out.width(0);
}
void value::dump_context_t::write_separator()
{
if (indent < 0)
return;
out.put(' ');
}
void value::dump_context_t::write_newline()
{
if (indent < 0)
return;
out.put('\n');
}
void value::dump(dump_context_t& context, int level) const
{
context.write_indent(level);
switch (m_Type)
{
case type_t::null:
context.out << "null";
break;
case type_t::object:
context.out << '{';
{
context.write_newline();
bool first = true;
for (auto& entry : *object_ptr(m_Storage))
{
if (!first) { context.out << ','; context.write_newline(); } else first = false;
context.write_indent(level + 1);
context.out << '\"' << entry.first << "\":";
if (!entry.second.is_structured())
{
context.write_separator();
entry.second.dump(context, 0);
}
else
{
context.write_newline();
entry.second.dump(context, level + 1);
}
}
if (!first)
context.write_newline();
}
context.write_indent(level);
context.out << '}';
break;
case type_t::array:
context.out << '[';
{
context.write_newline();
bool first = true;
for (auto& entry : *array_ptr(m_Storage))
{
if (!first) { context.out << ','; context.write_newline(); } else first = false;
if (!entry.is_structured())
{
context.write_indent(level + 1);
entry.dump(context, 0);
}
else
{
entry.dump(context, level + 1);
}
}
if (!first)
context.write_newline();
}
context.write_indent(level);
context.out << ']';
break;
case type_t::string:
context.out << '\"';
if (string_ptr(m_Storage)->find_first_of("\"\\/\b\f\n\r") != string::npos || string_ptr(m_Storage)->find('\0') != string::npos)
{
for (auto c : *string_ptr(m_Storage))
{
if (c == '\"') context.out << "\\\"";
else if (c == '\\') context.out << "\\\\";
else if (c == '/') context.out << "\\/";
else if (c == '\b') context.out << "\\b";
else if (c == '\f') context.out << "\\f";
else if (c == '\n') context.out << "\\n";
else if (c == '\r') context.out << "\\r";
else if (c == '\t') context.out << "\\t";
else if (c == 0) context.out << "\\u0000";
else context.out << c;
}
}
else
context.out << *string_ptr(m_Storage);
context.out << '\"';
break;
case type_t::boolean:
if (*boolean_ptr(m_Storage))
context.out << "true";
else
context.out << "false";
break;
case type_t::number:
context.out << *number_ptr(m_Storage);
break;
default:
break;
}
}
struct value::parser
{
parser(const char* begin, const char* end)
: m_Cursor(begin)
, m_End(end)
{
}
value parse()
{
value v;
// Switch to C locale to make strtod and strtol work as expected
auto previous_locale = std::setlocale(LC_NUMERIC, "C");
// Accept single value only when end of the stream is reached.
if (!accept_element(v) || !eof())
v = value(type_t::discarded);
if (previous_locale && strcmp(previous_locale, "C") != 0)
std::setlocale(LC_NUMERIC, previous_locale);
return v;
}
private:
struct cursor_state
{
cursor_state(parser* p)
: m_Owner(p)
, m_LastCursor(p->m_Cursor)
{
}
void reset()
{
m_Owner->m_Cursor = m_LastCursor;
}
bool operator()(bool accept)
{
if (!accept)
reset();
else
m_LastCursor = m_Owner->m_Cursor;
return accept;
}
private:
parser* m_Owner;
const char* m_LastCursor;
};
cursor_state state()
{
return cursor_state(this);
}
bool accept_value(value& result)
{
return accept_object(result)
|| accept_array(result)
|| accept_string(result)
|| accept_number(result)
|| accept_boolean(result)
|| accept_null(result);
}
bool accept_object(value& result)
{
auto s = state();
object o;
if (s(accept('{') && accept_ws() && accept('}')))
{
result = o;
return true;
}
else if (s(accept('{') && accept_members(o) && accept('}')))
{
result = std::move(o);
return true;
}
return false;
}
bool accept_members(object& o)
{
if (!accept_member(o))
return false;
while (true)
{
auto s = state();
if (!s(accept(',') && accept_member(o)))
break;
}
return true;
}
bool accept_member(object& o)
{
auto s = state();
value key;
value v;
if (s(accept_ws() && accept_string(key) && accept_ws() && accept(':') && accept_element(v)))
{
o.emplace(std::move(key.get<string>()), std::move(v));
return true;
}
return false;
}
bool accept_array(value& result)
{
auto s = state();
if (s(accept('[') && accept_ws() && accept(']')))
{
result = array();
return true;
}
array a;
if (s(accept('[') && accept_elements(a) && accept(']')))
{
result = std::move(a);
return true;
}
return false;
}
bool accept_elements(array& a)
{
value v;
if (!accept_element(v))
return false;
a.emplace_back(std::move(v));
while (true)
{
auto s = state();
v = nullptr;
if (!s(accept(',') && accept_element(v)))
break;
a.emplace_back(std::move(v));
}
return true;
}
bool accept_element(value& result)
{
auto s = state();
return s(accept_ws() && accept_value(result) && accept_ws());
}
bool accept_string(value& result)
{
auto s = state();
string v;
if (s(accept('\"') && accept_characters(v) && accept('\"')))
{
result = std::move(v);
return true;
}
else
return false;
}
bool accept_characters(string& result)
{
int c;
while (accept_character(c))
{
CRUDE_ASSERT(c < 128); // #todo: convert characters > 127 to UTF-8
result.push_back(static_cast<char>(c));
}
return true;
}
bool accept_character(int& c)
{
auto s = state();
if (accept('\\'))
{
return accept_escape(c);
}
else if (expect('\"'))
return false;
// #todo: Handle UTF-8 sequences.
return s((c = peek()) >= 0) && advance();
}
bool accept_escape(int& c)
{
if (accept('\"')) { c = '\"'; return true; }
if (accept('\\')) { c = '\\'; return true; }
if (accept('/')) { c = '/'; return true; }
if (accept('b')) { c = '\b'; return true; }
if (accept('f')) { c = '\f'; return true; }
if (accept('n')) { c = '\n'; return true; }
if (accept('r')) { c = '\r'; return true; }
if (accept('t')) { c = '\t'; return true; }
auto s = state();
string hex;
hex.reserve(4);
if (s(accept('u') && accept_hex(hex) && accept_hex(hex) && accept_hex(hex) && accept_hex(hex)))
{
char* end = nullptr;
auto v = std::strtol(hex.c_str(), &end, 16);
if (end != hex.c_str() + hex.size())
return false;
c = static_cast<int>(v);
return true;
}
return false;
}
bool accept_hex(string& result)
{
if (accept_digit(result))
return true;
auto c = peek();
if ((c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f'))
{
advance();
result.push_back(static_cast<char>(c));
return true;
}
return false;
}
bool accept_number(value& result)
{
auto s = state();
string n;
if (s(accept_int(n) && accept_frac(n) && accept_exp(n)))
{
char* end = nullptr;
auto v = std::strtod(n.c_str(), &end);
if (end != n.c_str() + n.size())
return false;
if (v != 0 && !std::isnormal(v))
return false;
result = v;
return true;
}
return false;
}
bool accept_int(string& result)
{
auto s = state();
string part;
if (s(accept_onenine(part) && accept_digits(part)))
{
result += std::move(part);
return true;
}
part.resize(0);
if (accept_digit(part))
{
result += std::move(part);
return true;
}
part.resize(0);
if (s(accept('-') && accept_onenine(part) && accept_digits(part)))
{
result += '-';
result += std::move(part);
return true;
}
part.resize(0);
if (s(accept('-') && accept_digit(part)))
{
result += '-';
result += std::move(part);
return true;
}
return false;
}
bool accept_digits(string& result)
{
string part;
if (!accept_digit(part))
return false;
while (accept_digit(part))
;
result += std::move(part);
return true;
}
bool accept_digit(string& result)
{
if (accept('0'))
{
result.push_back('0');
return true;
}
else if (accept_onenine(result))
return true;
return false;
}
bool accept_onenine(string& result)
{
auto c = peek();
if (c >= '1' && c <= '9')
{
result.push_back(static_cast<char>(c));
return advance();
}
return false;
}
bool accept_frac(string& result)
{
auto s = state();
string part;
if (s(accept('.') && accept_digits(part)))
{
result += '.';
result += std::move(part);
}
return true;
}
bool accept_exp(string& result)
{
auto s = state();
string part;
if (s(accept('e') && accept_sign(part) && accept_digits(part)))
{
result += 'e';
result += std::move(part);
return true;
}
part.resize(0);
if (s(accept('E') && accept_sign(part) && accept_digits(part)))
{
result += 'E';
result += std::move(part);
}
return true;
}
bool accept_sign(string& result)
{
if (accept('+'))
result.push_back('+');
else if (accept('-'))
result.push_back('-');
return true;
}
bool accept_ws()
{
while (expect('\x09') || expect('\x0A') || expect('\x0D') || expect('\x20'))
advance();
return true;
}
bool accept_boolean(value& result)
{
if (accept("true"))
{
result = true;
return true;
}
else if (accept("false"))
{
result = false;
return true;
}
return false;
}
bool accept_null(value& result)
{
if (accept("null"))
{
result = nullptr;
return true;
}
return false;
}
bool accept(char c)
{
if (expect(c))
return advance();
else
return false;
}
bool accept(const char* str)
{
auto last = m_Cursor;
while (*str)
{
if (eof() || *str != *m_Cursor)
{
m_Cursor = last;
return false;
}
advance();
++str;
}
return true;
}
int peek() const
{
if (!eof())
return *m_Cursor;
else
return -1;
}
bool expect(char c)
{
return peek() == c;
}
bool advance(int count = 1)
{
if (m_Cursor + count > m_End)
{
m_Cursor = m_End;
return false;
}
m_Cursor += count;
return true;
}
bool eof() const
{
return m_Cursor == m_End;
}
const char* m_Cursor;
const char* m_End;
};
value value::parse(const string& data)
{
auto p = parser(data.c_str(), data.c_str() + data.size());
auto v = p.parse();
return v;
}
# if CRUDE_JSON_IO
std::pair<value, bool> value::load(const string& path)
{
// Modern C++, so beautiful...
std::unique_ptr<FILE, void(*)(FILE*)> file{nullptr, [](FILE* file) { if (file) fclose(file); }};
# if defined(_MSC_VER) || (defined(__STDC_LIB_EXT1__) && __STDC_WANT_LIB_EXT1__)
FILE* handle = nullptr;
if (fopen_s(&handle, path.c_str(), "rb") != 0)
return {value{}, false};
file.reset(handle);
# else
file.reset(fopen(path.c_str(), "rb"));
# endif
if (!file)
return {value{}, false};
fseek(file.get(), 0, SEEK_END);
auto size = static_cast<size_t>(ftell(file.get()));
fseek(file.get(), 0, SEEK_SET);
string data;
data.resize(size);
if (fread(const_cast<char*>(data.data()), size, 1, file.get()) != 1)
return {value{}, false};
return {parse(data), true};
}
bool value::save(const string& path, const int indent, const char indent_char) const
{
// Modern C++, so beautiful...
std::unique_ptr<FILE, void(*)(FILE*)> file{nullptr, [](FILE* file) { if (file) fclose(file); }};
# if defined(_MSC_VER) || (defined(__STDC_LIB_EXT1__) && __STDC_WANT_LIB_EXT1__)
FILE* handle = nullptr;
if (fopen_s(&handle, path.c_str(), "wb") != 0)
return false;
file.reset(handle);
# else
file.reset(fopen(path.c_str(), "wb"));
# endif
if (!file)
return false;
auto data = dump(indent, indent_char);
if (fwrite(data.data(), data.size(), 1, file.get()) != 1)
return false;
return true;
}
# endif
} // namespace crude_json