Hi.
I've really enjoyed Brent's Lava parser, and used them (with some modifications) to parse SQL for DB2 for an internal project. I'd like to share some of this work - at least the stuff that should be (fairly) easy to merge into Lava. There is more - but I don't really know how you'd translate Insert/Update/Delete statements from SQL into Magma.
I've stripped out most of the stuff that there just isn't any support for at this time (not to mention it was mostly DB2 specific - maybe the standard, but I'm not sure). I've made some changes to the AST, although I can't claim that all of them will work with Magma (since I haven't tried any at all). The changes are:
Common Table Expressions:
In the Statement section of the parser, I've added a section that deal with WITH clauses. This should have the effect of creating 'temporary' tables in the main select (roughly analogous to subQueries), and I think this should just work. Here's an example of a query using this:
with t1 as (select * from me), t2 as (select him from you) SELECT col1, wm.col2 from wamu wm WHERE col1 = 'me' AND wm.col2 != col1
There are several other things you can do with CTE's (such as recursive queries and putting change statements in them), but I doubt these will work as is - and really aren't to common. I think they make for nicer organized queries, though.
In the columnReference and tableReference I have added a schema attribute and accessors to deal with schemas, like: schema.table.column schema.table I think these might map to Namespaces if those ever make it into Squeak in a consistent manner. Otherwise, they could probably just be ignored in Magma, I guess.
In tableReferenceList, I've added a joinTableReference clause. This allows for things like: from table1 join table2 on table1.col = table2.col This is the 'new' standard for joins (SQL-92) that several database vendors have been pushing. The code to use it in Magma probably isn't fully thought out - it currently uses a JoinedTableReference class to represent this. Currently this reduces the JoinedTableReference to a LaTableReference, and puts the joinConditions (on clause) in the joinCondition part of the LaSelection. To make it fully useful with minimal work, I think you could move the joinConditions to the whereCondition, and it should just work.
In tableAlias, I've added a clause where you can just use the an alias without the "as". This is valid (at least in DB2).
In predicate, I've added an existsPredicate. This causes the subquery to run, and if something is found, then that rows (from the outer query) is returned, else it isn't. Also, a not exists is present, so: [not] exists (select 1 from table where name = 'me') This is represented in the AST, but I have no idea or suggestions at this time as to how this should work with Magma.
Finally, in literal, I've added a "null" string, which should probably equate to nil internally. Or at least I think I did - it looks like it is already in version .36, so maybe that was already there. Oh well.
Oh, and I also added a lot of #qualifier messages to several of the AST classes - that was so I could analyze the parsed results for my purposes, and I just left them in.
Here's my Parser definition (based off of your Monticello version 31) and a change set containing the AST changes.
Thanks, Chris Cunningham