Apparently some of my responses related to the posts on this subject disappeared into the bit bucket. I apologize.

Here is a summary of my responses. Please do not take my question as a complaint. I was simply thinking about implementation of something similar to the following hierarchy which was useful in the past:

TreeNode Expression RelationalDatabaseExpression SQLExpression SQLRequest SQLSelectStatement SQLUpdateStatement SQLInsertStatement SQLClause SQLInsert SQLSelect SQLUpdate SQLFrom SQLWhere SQLHaving SQLOrderBy . . .

And so forth down to the lowest level SQL primitives since everything in SQL is an expression. If there is a better way of representing the above, I would love to know.

I can understand the difficulty of getting general agreement on how best to design and implement a base class for all uses. Was this caused by fundamental differences on the most primitive uses or because there was a desire to do too much in such a base class?

I will definitely take a look at TreeWorks80.

Thanks for your responses.

Jerome

jegarcia@adventurousmind.com

______________________________ Reply Separator _________________________________ Subject: Re: Does Squeak include a generic node class? Author: Sam Adams ssadams@us.ibm.com at INTERNET Date: 9/22/98 2:46 PM

Nope, but I just posted the code for TreeWorks80.cs to UIUC. It should be available in a couple of days under the name 'TreeWorks80.cs'. TreeWorks80 was a comprehensive set of models, editors, views and controllers for hierarchical structures. It was originally written by Lynn Fogwell and Ken Auer at KSC in the early 90's, and was included in the KSC ST archives that were released last year. I ported the code to Squeak 1.23 and it worked fine there, along with the rest of the KSC libraries and my compatibility mods to the image. I haven't ported it to 2.1+ yet, but the model objects at least should work fine.

Regards, Sam

Sam S. Adams, Distinguished Engineer, IBM Network Computing Software Division tie line 444-0736, outside 919-254-0736, email: ssadams@us.ibm.com <<Hebrews 11:6, Proverbs 3:5-6, Romans 1:16-17, I Corinthians 1:10>>