nested groups fails to parse

[aeb-dev]

Language => Expr: (STRING (COMMA [d] STRING)*)?
Error => "unexpected "(" (LPAREN) at line 1, column 15.expecting IDENTIFIER, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting RPAREN, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting IDENTIFIER, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting RPAREN, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting IDENTIFIER, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting RPAREN, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting IDENTIFIER, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting RPAREN, unexpected "(" (LPAREN) at line 1, column 15.expecting IDENTIFIER, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting RPAREN, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting IDENTIFIER, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting RPAREN, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting IDENTIFIER, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting RPAREN, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting IDENTIFIER, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting DISCARD, unexpected "(" (LPAREN) at line 1, column 15.expecting RPAREN, "

when I change language to this: Expr: (STRING COMMA [d] STRING)?
no problem occurs

Am I doing something wrong or nested groups are not supported?

[b3b00]

hi @Mrmumu, first glad to see that you looked at CSLY.
for now nested groups are supported. And I have no plan to support it any soon as I son't see any usefull use case.
for your specific case the best solution is I guess :

Expr : OptinnalExpr ?
OptionnalExpr: STRING (COMMA [d] STRING)*

May I ask you what you arelooking at in CSLY ?
Are you planning to use it for any special purpose ?

[b3b00]

The repeated error annoy me so I will look at it more precisely.

[aeb-dev]

for now nested groups are supported. And I have no plan to support it any soon as I son't see any usefull use case.

You mean are not supported I think.

Yes, I have solved it just like that:)

I was going to send an email to you actually, after I have finished the core of my project.

I am trying to implement XPath support for .net core. Right now, .net core only support XPath 1.0 but there is already XPath 3.1 recommendation on W3C. I'm trying to implement a lexer, parser for this grammar by using your project. There are other approaches but I would like to use the published grammar.

I have searched other lexer, parser approaches but your "embeddable" solution got me^^

[b3b00]

Great project that tout have! I am happy that the "embeddedable" feature of CSLY got you. It was my main concern when I started it. Glad to see that I am not tottaly wrong.