private String decimalPart() {
        int position = tokens.getPosition();
        boolean consumed = false;

        try {
            if (!tokens.skipNoIgnore(DOT)) return "";
            if (tokens.currentIsNoIgnore(NUMBER)) {
                consumed = true;
                return "." + tokens.next().toString();
            }
            return "";
        } finally {
            if ( ! consumed)
                tokens.setPosition(position);
        }
    }
Returns the specified term weight, or -1 if there is no weight suffix
container-search/src/main/java/com/yahoo/prelude/query/parser/StructuredParser.java