[antlr-interest] Re: SQL grammar tree construction problem
Joshua Davis
joshua.davis at kiodex.com
Fri Nov 7 05:01:17 PST 2003
ANTLR newbie question:
I've been having a similar problem I think. I made a very simple
grammar based on L. V.'s grammar. It seems to be always producing
only one root node, with no children. What steps should I take to
debug this? I have tried adding actions to the rules, and it looks
like the rules are being triggered correctly, but no AST is produced.
--- In antlr-interest at yahoogroups.com, "lgcraymer" <lgc at m...> wrote:
> Gustav--
>
> You cannot make a rule a root--that's what ANTLR is complaining
about.
> Rules may represent subtrees, so only nodes with token ids (TEXT
or
> STRING, for example) can be followed with ^.
>
> --Loring
>
>
> --- In antlr-interest at yahoogroups.com, Gustav Boström
<i93gusbo at h...>
> wrote:
> > Hello!
> >
> > I'm trying to use Lubos Vnuk's (Thanks for doing all the work!)
SQL-
> > grammar in order to do some
> > processing on SQL-statments. I would for example like to find out
> > which columns are affected by a DML-statement and which
parameters
> > correspond to which columns.
> >
> > I'm doing this is in Java , so I've changed the grammar slightly.
> > I've removed the C++ actions or replaced them with Java versions.
> >
> > My thought was to add AST-construction and then navigate the tree
to
> > find out the stuff I need. This is where I run into problems.
> > I tried to annotate the rules with ^ to construct my tree, but it
> > keeps giving me "unexpected token:^" when I try to dothis for
> example:
> > sql_stmt :
> > sql_data_stmt^
> > ;
> >
> > I've set the options to buildAST=true;
> > I'm using version 2.7.2.
> >
> > Any ideas on what can be wrong?
> >
> > Cheers,
> >
> > Gustav Boström
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
More information about the antlr-interest
mailing list