`SELECT ... WHERE match(key, '^prefix...')`
should use index similarly to
`SELECT ... WHERE key LIKE 'prefix%'`
{
        "equals",
        [] (RPNElement & out, const Field & value)
        {
            out.function = RPNElement::FUNCTION_IN_RANGE;
            out.range = Range(value);
            return true;
        }
    },
    {
        "less",
        [] (RPNElement & out, const Field & value)
        {
            out.function = RPNElement::FUNCTION_IN_RANGE;
            out.range = Range::createRightBounded(value, false);
            return true;
        }
    },
    {
        "greater",
        [] (RPNElement & out, const Field & value)
        {
            out.function = RPNElement::FUNCTION_IN_RANGE;
            out.range = Range::createLeftBounded(value, false);
            return true;
        }
    },
    {
        "lessOrEquals",
        [] (RPNElement & out, const Field & value)