Function unicodeEscape

demos/lib/Mental.js:6991–7031

(first)

                    }

                    function unicodeEscape(first) {
                        pos++;
                        var chr1 = code.charCodeAt(pos), chr2 = code.charAt(pos + 1), chr3 = code.charAt(pos + 2), chr4 = code.charAt(pos + 3), chr5 = code.charAt(pos + 4), hex;
                        if (chr1 !== 0x75) {
                            error("Invalid unicode escape. Expected u.");
                        }
                        hex = +('0x' + chr2 + chr3 + chr4 + chr5);
                        if ((hex === hex && hex !== hex) || /[^a-f0-9]/i.test(''+chr2+chr3+chr4+chr5)) {
                            error("Invalid unicode escape. Expected valid hex sequence.");
                        }
                        if (first) {
                            if (hex > 0x60 && hex < 0x7b) {
                            } else if (hex > 0x40 && hex < 0x5b) {
                            } else if (hex === 0x5f || hex === 0x24) {
                            } else if (!isValidVariable(hex)) {
                                error('illegal unicode escape');
                            }
                        } else {
                            if (hex > 0x60 && hex < 0x7b) {
                            } else if (hex > 0x2f && hex < 0x3a) {
                            } else if (hex > 0x40 && hex < 0x5b) {
                            } else if (hex === 0x5f || hex === 0x24) {
                            } else if (!isValidVariablePart(hex)) {
                                error('illegal unicode escape');
                            }
                        }
                        pos += 5;
                        if (first) {
                            if (pos < len) {
                                outputLine += '\\u' + chr2 + chr3 + chr4 + chr5;
                                nonKeyword();
                                return false;
                            } else {
                                outputLine += '\\u' + chr2 + chr3 + chr4 + chr5 + '$';
                                identifierStates();
                                identifierAsi();
                            }
                        } else {
                            outputLine += '\\u' + chr2 + chr3 + chr4 + chr5;
                        }
                    }

                    function keyword(iLen) {
                        state = -1;