src/main/java/com/github/fge/grappa/parsers/BaseParser.java
@Cached
    @DontLabel
    public Rule charRange(final char cLow, final char cHigh)
    {
        return cLow == cHigh ? ch(cLow) : new CharRangeMatcher(cLow, cHigh);
    }
@Cached
    @DontLabel
    public Rule charRange(final char cLow, final char cHigh)
    {
        return cLow == cHigh ? ch(cLow) : new CharRangeMatcher(cLow, cHigh);
    }
Match an inclusive range of {@code char}s

@param cLow the start char of the range (inclusively)
@param cHigh the end char of the range (inclusively)
@return a rule