public String scanSymbolWithSeperator(final SymbolTable symbolTable, char serperator) {
        matchStat = UNKNOWN;

        int offset = 0;
        char chLocal = charAt(bp + (offset++));

        if (chLocal == 'n') {
            if (charAt(bp + offset) == 'u' && charAt(bp + offset + 1) == 'l' && charAt(bp + offset + 2) == 'l') {
                offset += 3;
                chLocal = charAt(bp + (offset++));
            } else {
                matchStat = NOT_MATCH;
                return null;
            }

            if (chLocal == serperator) {
                bp += offset;
                this.ch = this.charAt(bp);
                matchStat = VALUE;
                return null;
            } else {
                matchStat = NOT_MATCH;
                return null;
            }
        }

        if (chLocal != '"') {
            matchStat = NOT_MATCH;
            return null;
        }

        String strVal;
        // int start = index;
        int hash = 0;
        for (;;) {
            chLocal = charAt(bp + (offset++));
            if (chLocal == '\"') {
                // bp = index;
                // this.ch = chLocal = charAt(bp);
                int start = bp + 0 + 1;
                int len = bp + offset - start - 1;
                strVal = addSymbol(start, len, hash, symbolTable);
                chLocal = charAt(bp + (offset++));
                break;
            }

            hash = 31 * hash + chLocal;

            if (chLocal == '\\') {
                matchStat = NOT_MATCH;
                return null;
            }
        }

        for (;;) {
            if (chLocal == serperator) {
                bp += offset;
                this.ch = this.charAt(bp);
                matchStat = VALUE;
                return strVal;
            } else {
                if (isWhitespace(chLocal)) {
                    chLocal = charAt(bp + (offset++));
                    continue;
                }

                matchStat = NOT_MATCH;
                return strVal;
            }
        }
    }
internal method, don't invoke
@param token
src/main/java/com/alibaba/fastjson/parser/JSONLexerBase.java