From: Matthew Desmarais <desmarm@...>
Date: 2006-03-05T04:56:25+09:00
Subject: Re: Kirbybase Hacks NilClass

James Edward Gray II wrote:
> On Mar 4, 2006, at 12:04 PM, Jamey Cribbs wrote:
>
>> What has been kicked around when this question has come up before is 
>> for me to create something like a NULL class and use this to 
>> designate a null value in the database, instead of using nil.
>
> I know I would feel a lot safer with that.  The only minus there is 
> that NULL will be a true value, again with surprising behavior for 
> people who are expecting normal Ruby.  If we have to have one though, 
> I would prefer this one by far.
>
>> It would bring up a few other problems, namely, what if someone wants 
>> to store the string value NULL in a field.  But I imagine these could 
>> be overcome.
>
> Could it be stored using Kirbybase's escapes (&NULL;)?
>
> James Edward Gray II
>
>
Without thinking too deeply about this, I came up with using a marker 
value to designate non-NULL values.  When a field is written, use '*' as 
the first character and then write the field's value.  NULL is written 
as the empty string.  When reading a field, test to see if it's the 
empty string.  If it is then your value is NULL, otherwise toss the 
first character and read your non-null value after that.

This is probably pretty naive and it would introduce some extra 
performance overhead though.  Just a thought.