[antlr-interest] antlr 3.1 ast rewriting

[Floris van Nee]

Hi Johannes,

I've attached the lexer/parser file. If you generate that first and then
generate the tree grammar, you'll get the error when compiling the generated
code.

Floris

On Thu, Mar 12, 2009 at 8:16 AM, Johannes Luber <jaluber at gmx.de> wrote:

> Floris van Nee schrieb:
> > Hello!
> >
> > I've got a question about rewriting an AST in a tree grammar, with C# as
> > target language. The code Antlr generates just won't compile when I set
> > the 'output=AST' in my tree grammar options.
> > It complains about lines like this:
> >
> > if ( _first_1==null ) _first_1 = qual.Tree;
> >
> > Error    2    Cannot implicitly convert type 'object' to
> > 'Antlr.Runtime.Tree.CommonTree'. An explicit conversion exists (are you
> > missing a cast?)    C:\Users\floris\Documents\Visual Studio
> > 2008\Projects\Vnvd\Vnvd\vNVDCheckerPassTwo.cs    315    58    Vnvd
> >
> > Here _first_1 is of type CommonTree, and qual.Tree of type object. It
> > needs an explicit cast there, but when Antlr generates the code, it
> > doesn't add one. Is this something I did wrong in my grammar file, or is
> > this a bug?
> > I am using the latest version of Antlr (3.1.2).
> >
> > Thanks in advance,
> > Floris
>
> I need a full working grammar, which includes at least the .tokens-file.
> I haven't tested yet, if that is enough or if I do need also the parser
> and lexer. Full working means that I can generate the grammar on my
> system so I can look up where I seemingly missed the conversion.
>
> Johannes
> >
> > Here are the contents of my (simplified) grammar file:
> >
> > tree grammar vNVDCheckerPassTwo;
> >
> > options
> > {
> >     ASTLabelType = CommonTree;
> >     tokenVocab = vNVD;
> >     language = CSharp2;
> >     rewrite = true;
> >     output = AST;
> > }
> >
> > program
> >     :    ^(node=PROGRAM import_stat* namespace_decl*)
> >     ;
> >
> > import_stat
> >     :    ^(node=USING qual=qualifier)
> >     ;
> >
> > namespace_decl
> >     :    ^(node=NAMESPACE qual=qualifier (namespace_decl)*)
> >     ;
> >
> > qualifier
> >     :    ^(fqual=FQUALIFIER IDENTIFIER+)
> >     ;
> >
> >
> >
> > ------------------------------------------------------------------------
> >
> >
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