String:
const jsEscapeRegex = /\\(u\{([0-9A-Fa-f]+)\}|u([0-9A-Fa-f]{4})|x([0-9A-Fa-f]{2})|([1-7][0-7]{0,2}|[0-7]{2,3})|(['"tbrnfv0\\]))|\\U([0-9A-Fa-f]{8})/g;
const usualEscapeSequences = {
'0': '\0',
'b': '\b',
'f': '\f',
'n': '\n',
'r': '\r',
't': '\t',
'v': '\v',
'\'': '\'',
'"': '"',
'\\': '\\'
};
const fromHex = (str) => String.fromCodePoint(parseInt(str, 16));
const fromOct = (str) => String.fromCodePoint(parseInt(str, 8));
function unescape(string) {
return string.replace(jsEscapeRegex, (_, __, varHex, longHex, shortHex, octal, specialCharacter, python) => {
if (varHex !== undefined) {
return fromHex(varHex);
} else if (longHex !== undefined) {
return fromHex(longHex);
} else if (shortHex !== undefined) {
return fromHex(shortHex);
} else if (octal !== undefined) {
return fromOct(octal);
} else if (python !== undefined) {
return fromHex(python);
} else {
return usualEscapeSequences[specialCharacter];
}
});
}