private void scanOperator()

in core/src/main/java/com/alibaba/druid/sql/parser/Lexer.java [1527:1745]
217 lines of code
54 McCabe index (conditional complexity)

    private void scanOperator() {
        switch (ch) {
            case '+':
                scanChar();
                token = Token.PLUS;
                break;
            case '-':
                scanChar();
                if (ch == '>') {
                    scanChar();
                    if (ch == '>') {
                        scanChar();
                        token = Token.SUBGTGT;
                    } else {
                        token = Token.SUBGT;
                    }
                } else {
                    token = Token.SUB;
                }
                break;
            case '*':
                scanChar();
                token = Token.STAR;
                break;
            case '/':
                scanChar();
                token = Token.SLASH;
                break;
            case '&':
                scanChar();
                if (ch == '&') {
                    scanChar();
                    token = Token.AMPAMP;
                } else {
                    token = Token.AMP;
                }
                break;
            case '|':
                scanChar();
                if (ch == '|') {
                    scanChar();
                    if (ch == '/') {
                        if (charAt(pos + 1) == '*') {
                            token = Token.BARBAR;
                            break;
                        }
                        scanChar();
                        token = Token.BARBARSLASH;
                    } else {
                        token = Token.BARBAR;
                    }
                } else if (ch == '/') {
                    scanChar();
                    token = Token.BARSLASH;
                } else {
                    token = Token.BAR;
                }
                break;
            case '^':
                scanChar();
                if (ch == '=') {
                    scanChar();
                    token = Token.CARETEQ;
                } else {
                    token = Token.CARET;
                }
                break;
            case '%':
                scanChar();
                token = Token.PERCENT;
                break;
            case '=':
                scanChar();
                if (ch == ' ') {
                    scanChar();
                }

                if (ch == '=') {
                    scanChar();
                    token = Token.EQEQ;
                } else if (ch == '>') {
                    scanChar();
                    token = Token.EQGT;
                } else {
                    token = Token.EQ;
                }
                break;
            case '>':
                scanChar();
                if (ch == '=') {
                    scanChar();
                    token = Token.GTEQ;
                } else if (ch == '>') {
                    scanChar();
                    if (ch == '>') {
                        scanChar();
                        token = Token.GTGTGT;
                    } else {
                        token = Token.GTGT;
                    }
                } else {
                    token = Token.GT;
                }
                break;
            case '<':
                scanChar();
                if (ch == '=') {
                    scanChar();
                    if (ch == '>') {
                        token = Token.LTEQGT;
                        scanChar();
                    } else {
                        token = Token.LTEQ;
                    }
                } else if (ch == '>') {
                    scanChar();
                    token = Token.LTGT;
                } else if (ch == '<') {
                    scanChar();

                    if (ch == '<') {
                        scanChar();
                        token = Token.LTLTLT;
                    } else {
                        token = Token.LTLT;
                    }
                } else if (ch == '@') {
                    scanChar();
                    token = Token.LT_MONKEYS_AT;
                } else if (ch == '-' && charAt(pos + 1) == '>') {
                    scanChar();
                    scanChar();
                    token = Token.LT_SUB_GT;
                } else {
                    if (ch == ' ') {
                        char c1 = charAt(pos + 1);
                        if (c1 == '=') {
                            scanChar();
                            scanChar();
                            if (ch == '>') {
                                token = Token.LTEQGT;
                                scanChar();
                            } else {
                                token = Token.LTEQ;
                            }
                        } else if (c1 == '>') {
                            scanChar();
                            scanChar();
                            token = Token.LTGT;
                        } else if (c1 == '<') {
                            scanChar();
                            scanChar();
                            token = Token.LTLT;
                        } else if (c1 == '@') {
                            scanChar();
                            scanChar();
                            token = Token.LT_MONKEYS_AT;
                        } else if (c1 == '-' && charAt(pos + 2) == '>') {
                            scanChar();
                            scanChar();
                            scanChar();
                            token = Token.LT_SUB_GT;
                        } else {
                            token = Token.LT;
                        }
                    } else {
                        token = Token.LT;
                    }
                }
                break;
            case '!':
                scanChar();
                while (isWhitespace(ch)) {
                    scanChar();
                }
                if (ch == '=') {
                    scanChar();
                    token = Token.BANGEQ;
                } else if (ch == '>') {
                    scanChar();
                    token = Token.BANGGT;
                } else if (ch == '<') {
                    scanChar();
                    token = Token.BANGLT;
                } else if (ch == '!') {
                    scanChar();
                    token = Token.BANGBANG; // postsql
                } else if (ch == '~') {
                    scanChar();
                    if (ch == '*') {
                        scanChar();
                        token = Token.BANG_TILDE_STAR; // postsql
                    } else {
                        token = Token.BANG_TILDE; // postsql
                    }
                } else {
                    token = Token.BANG;
                }
                break;
            case '?':
                scanChar();
                token = Token.QUES;
                break;
            case '~':
                scanChar();
                if (ch == '*') {
                    scanChar();
                    token = Token.TILDE_STAR;
                } else if (ch == '=') {
                    scanChar();
                    token = Token.TILDE_EQ; // postsql
                } else {
                    token = Token.TILDE;
                }
                break;
            default:
                throw new ParserException("TODO. " + info());
        }
    }