uce/src/lib/dtree.h

struct DTree;

struct DTree {

	char type = 'S';

	string 	_string;
	f64 	_float;
	bool	_bool;
	void*	_ptr;
	std::map<string, DTree> _map;

	void each(std::function <void (DTree t, string key)> f)
	{
		switch(type)
		{
			case('M'):
				for (auto it = _map.begin(); it != _map.end(); ++it)
				{
					f(it->second, it->first);
				}
				break;
			default:
				f(*this, "");
				break;
		}
	}

	bool is_array()
	{
		return(type == 'M');
	}

	string to_string()
	{
		switch(type)
		{
			case('S'):
				return(_string);
				break;
			case('F'):
				return(std::to_string(_float));
				break;
			case('B'):
				return(_bool ? "true" : "false");
				break;
			case('M'):
				return("(array)");
				break;
			case('P'):
				return(to_hex((u64)_ptr));
				break;
		}
	}

	string to_json()
	{
		switch(type)
		{
			case('S'):
				return(json_escape(_string));
				break;
			case('F'):
				return(std::to_string(_float));
				break;
			case('B'):
				return(_bool ? "true" : "false");
				break;
			case('M'):
				return("\"(array)\"");
				break;
			case('P'):
				return("\"(pointer)\"");
				break;
		}
	}

	string get_type_name()
	{
		switch(type)
		{
			case('S'):
				return("string");
				break;
			case('F'):
				return("f64");
				break;
			case('B'):
				return("bool");
				break;
			case('M'):
				return("array");
				break;
			case('P'):
				return("pointer");
				break;
		}
	}

	void set(string s)
	{
		if(type == 'M') _map.clear();
		type = 'S';
		_string = s;
	}

	void set(void* p)
	{
		if(type == 'M') _map.clear();
		type = 'P';
		_ptr = p;
	}

	void set(f64 f)
	{
		if(type == 'M') _map.clear();
		type = 'F';
		_float = f;
	}

	void set_bool(bool b)
	{
		if(type == 'M') _map.clear();
		type = 'B';
		_bool = b;
	}

	DTree* key(string s)
	{
		type = 'M';
		return(&_map[s]);
	}

	DTree& operator [] (string s) {
		type = 'M';
		return(_map[s]);
	}

	void operator = (string v) { set(v); }
	void operator = (f64 v) { set(v); }
	void operator = (void* v) { set(v); }
	void operator = (DTree v) { *this = v; }

	void remove(string s)
	{
		type = 'M';
		_map.erase(s);
	}

	void clear()
	{
		type = 'M';
		_map.clear();
	}

};

string to_string(DTree t)
{
	return(t.to_string());
}

string json_encode(DTree t)
{
	string result = "";
	if(t.is_array())
	{
		result += "{";
		u32 count = 0;
		t.each([&] (DTree item, string key) {
			if(count > 0)
				result += ", ";
			count += 1;
			result += json_escape(key) + ": " + json_encode(item);
		});
		result += "}";
	}
	else
	{
		result = t.to_json();
	}
	return(result);
}

// https://i.stack.imgur.com/SHLOB.gif
string json_decode_string(string s, u32& i)
{
	string result;
	while(i < s.length())
	{
		char c = s[i];
		if(c == '"')
		{
			i += 1;
			return(result);
		}
		else if(c == '\\')
		{
			i += 1;
			c = s[i];
			switch(c)
			{
				case('t'):
					result.append('\t', 1);
					break;
				case('n'):
					result.append('\n', 1);
					break;
				case('r'):
					result.append('\r', 1);
					break;
				case('\\'):
					result.append('\\', 1);
					break;
				case('b'):
					result.append('\b', 1);
					break;
				case('f'):
					result.append('\f', 1);
					break;
				case('u'):
					// todo decode
					break;
				default:
					result.append(c, 1);
					break;
			}
		}
		else
		{
			result.append(c, 1);
		}
		i += 1;
	}
	return(result);
}

DTree json_decode_map(string s, u32& i);

void json_consume_space(string s, u32& i)
{
	while(i < s.length() && isspace(s[i]))
		i += 1;
}

string json_decode_keyword(string s, u32& i)
{
	string result;
	json_consume_space(s, i);
	while(i < s.length())
	{
		char c = s[i];
		if(isalnum(c))
		{
			result.append(c, 1);
		}
		else
		{
			return(result);
		}
		i += 1;
	}
	return(result);
}

string json_decode_number(string s, u32& i)
{
	string result;
	json_consume_space(s, i);
	while(i < s.length())
	{
		char c = s[i];
		if(isdigit(c) || c == '.')
		{
			result.append(c, 1);
		}
		else
		{
			return(result);
		}
		i += 1;
	}
	return(result);
}

DTree json_decode_value(string s, u32& i)
{
	DTree result;
	string value = "";
	json_consume_space(s, i);
	char c = s[i];
	result.set("CHAR_");
	result._string.append(to_string(c));
	return(result);
	if(c == '"') // string value
	{
		result.type = 'S';
		i += 1;
		result._string = json_decode_string(s, i);
		return(result);
	}
	else if(isdigit(c))
	{
		result.type = 'S';
		result._string = json_decode_number(s, i);
		//result._float = stod(json_decode_number(s, i));
		return(result);
	}
	else if(c == '{')
	{
		i += 1;
		return(json_decode_map(s, i));
	}
	else
	{
		value = json_decode_keyword(s, i);
		if(value == "true")
			result.set_bool(true);
		else if(value == "false")
			result.set_bool(false);
		else if(value == "null")
			result.set("");
		return(result);
	}
	return(result);
}

DTree json_decode_map(string s, u32& i)
{
	DTree result;
	string key = "";
	while(i < s.length())
	{
		json_consume_space(s, i);
		char c = s[i];
		if(c == '}')
		{
			return(result);
		}
		else if(c == ',')
		{

		}
		else if(c == '"')
		{
			i += 1;
			key = json_decode_string(s, i);
			json_consume_space(s, i);
			if(s[i] != ':')
				return(result); // malformed
			result[key] = json_decode_value(s, i);
		}
		else
		{
			// malformed
			return(result);
		}
		i += 1;
	}
	return(result);
}

DTree json_decode(string s)
{
	u32 i = 0;
	return(json_decode_value(s, i));
}

string var_dump(DTree map, string prefix = "", string postfix = "\n")
{
	string result = "";
	if(!map.is_array())
		return(map.to_string());
	map.each([&] (DTree item, string key) {
		result += prefix + key + ": " + item.to_string() + postfix;
		if(item.is_array())
			result += var_dump(item, prefix + "\t");
	});
	return(result);
}