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 at adventurousmind.com


______________________________ Reply Separator _________________________________
Subject: Re: Does Squeak include a generic node class?
Author:  Sam Adams <ssadams at 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 at us.ibm.com
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