[antlr-interest] [CSharp3] rule visibility in composite grammars

[Ranco Marcus]

Hi Sam/all,

When a (tree) grammar C imports (tree) grammars A and B, where grammar A calls a rule R from grammar B, a call is being made from delegate parser C_A to a delegate rule R (targeting C_B) in the composite parser C (its parent).

Now that the visibility of the delegate rules in C match the visibility of the imported grammar, the rule R has to be made public for the above to work. In our grammars, we build up internal structures that are subsequently processed. In our case, that means that all those internal structures have to be made public as well. This could be solved by allowing ANTLR rules to have 'internal' visibility. Also, imported grammars can probably remain internal as well. 

What are your thoughts on this? 

Thanks, Ranco

> -----Original Message-----
> From: Sam Harwell [mailto:sharwell at pixelminegames.com]
> Sent: Thursday, April 07, 2011 3:57 PM
> To: Ranco Marcus; antlr-interest at antlr.org
> Subject: RE: [antlr-interest] [CSharp3] rule visibility in composite grammars
> 
> The visibility of delegated rules now matches the way they're declared in the
> imported grammar. Since some of them return nested classes declared in the
> delegate grammar, I had to make the delegate grammar 'public' and all its
> rules 'internal'.
> 
> I fixed the reserved names issue right after releasing 3.3.1, so it'll be included
> when I release 3.3.2. Note that rule parameters and return values need to
> include an explicit '@' in their declarations in the grammar, as follows. Labels
> and rule names do not need the '@'.
> 
> namespace[int @in] returns [int @out] : as=A B;
> 
> Sam
> 
> -----Original Message-----
> From: Ranco Marcus [mailto:ranco.marcus at epirion.nl]
> Sent: Thursday, April 07, 2011 6:49 AM
> To: Sam Harwell; antlr-interest at antlr.org
> Subject: RE: [antlr-interest] [CSharp3] rule visibility in composite grammars
> 
> Sounds great, Sam!
> 
> What will be the visibility of the methods in the 'Delegated rules' region now
> that the class of the imported grammar is internal? Private or internal?
> 
> Another small suggestion is to prefix variable names (at least those that are
> reserved in C#) with an at-sign. The generated class for the grammar below
> has a compile error since 'as' is not a valid variable name while '@as' is.
> 
> name : as=firstName lastName;
> 
> Are you planning to release new binaries any time soon?
> 
> Thanks again,
> 
> Ranco Marcus
> 
> > -----Original Message-----
> > From: Sam Harwell [mailto:sharwell at pixelminegames.com]
> > Sent: woensdag 6 april 2011 17:20
> > To: Ranco Marcus; antlr-interest at antlr.org
> > Subject: RE: [antlr-interest] [CSharp3] rule visibility in composite
> > grammars
> >
> > Hi Ranco,
> >
> > I made the following changes so far:
> >
> > * An imported grammar is always generated as an internal class instead
> > of a public class.
> > * Rules within the imported grammar are always declared public since
> > they are only called by the root grammar.
> >
> > How does that sound?
> >
> > Sam
> >
> > -----Original Message-----
> > From: antlr-interest-bounces at antlr.org
> > [mailto:antlr-interest-bounces at antlr.org] On Behalf Of Ranco Marcus
> > Sent: Wednesday, March 23, 2011 6:40 AM
> > To: antlr-interest at antlr.org
> > Subject: [antlr-interest] [CSharp3] rule visibility in composite
> > grammars
> >
> > Hi all/Sam,
> >
> > While using the CSharp3 target on a composite grammar, I came across a
> > few issues regarding rule visibility.
> >
> > If no modifier (private, protected, public, ...) is specified for a
> > rule, the Java target generates public methods (since it is not
> > implemented IIRC) and the
> > CSharp3 target generates private methods.
> >
> > I like the idea to explicitly specify which rules are callable (by
> > making them public). However, for composite grammars the generated
> > parser contains delegate rules for every rule of the imported grammar,
> > even for rules in the imported grammar that aren't public (causing
> > compile errors). This can solved this adding a public modifier to
> > every rule of the imported grammar, but I was wondering if there's a
> > more
> convenient way of doing this.
> >
> > Furthermore, the methods for the delegate rules in the composite
> > grammars are all public, regardless of the visibility of the rule in
> > the
> imported grammar.
> > IMHO, it would be better to make them private and use the composite
> > grammar to explicitly specify the rules that are externally visible.
> > What are your thoughts on this?
> >
> > Btw, the CSharp3 templates are also included in the original Java
> > tool. Does that mean that we don't need the .NET version of the tool
> anymore?
> >
> >
> > Best regards,
> >
> > Ranco Marcus
> > Epirion Knowledge Solutions B.V.
> >
> >
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