function decode(encoded) {
	let result = '';
	for (let i = 0; i < encoded.length; i++) {
		let c = encoded[i];
		if (c == '+') {
			result += ' ';
		} else if (c == '%') {
			result += String.fromCharCode(parseInt(encoded.slice(i + 1, i + 3), 16));
			i += 2;
		} else {
			result += c;
		}
	}
	return result;
}

function decodeForm(encoded, initial) {
	let result = initial || {};
	if (encoded) {
		encoded = encoded.trim();
		let items = encoded.split('&');
		for (let i = 0; i < items.length; i++) {
			let item = items[i];
			let equals = item.indexOf('=');
			let key = decode(item.slice(0, equals));
			let value = decode(item.slice(equals + 1));
			result[key] = value;
		}
	}
	return result;
}

export {decodeForm};