aparser | An async ARGV node.js parser | Reactive Programming library

I can't tell for sure (you just have eclipses in the Common Lexer extract), but in the original Lexer grammar IDENTIFIER would only be matched if you had been pushed the VALUE_MODE. It appears that you've lost that characteristic when you created the Common Lexer. Since it's "in the open" in the common Lexer, it will match whether or not you're in VALUE_MODE (and the length will make it a stronger match). That explains the different behavior.

Your IDENTIFIER lexer rule matches a longer string of characters than COMMAND_START, so it will take precedence. You'll not get a "hit" on the COMMAND_START rule to push you into COMMAND_MODE. This is the heart of your problem. Your IDENTIFIER rule overlaps the COMMAND_START rule and will always be at least as long (1 character) or longer than the COMMAND_START rule match, so ANTLR will always favor it.

Without the fragment definitions for A_Z, UNDERSCORE, DIGIT, and WS (You're using them like fragments, so I assume they are), it's pretty tough to determine what you intend to be the difference between a COMMAND and an IDENTIFIER.

The way you have COMMAND_START to trigger a mode only to pop it immediately is "unusual". I would expect to see a COMMAND Lexer rule that incorporated the whole pattern:

Your DTO does not match the structure of the response you are parsing. You have a nested structure where on DTO you are expecting only to receive primitive values. On upper level you have a structure with two fields.

If the two parsers don't return the same data, they do not have a related interface and probably shouldn't have a common base class.

If they do return the same data, put the GetData function in the base class. Or better yet, return the data directly from Parse.

Let me see if I can clarify what you are trying to do.

You have a set of parsers (AParser, BParser, CParser) that have specific implementations of some of the functions of BaseParser. What you are trying to do is to give specific instances of AParser, BParser etc some special feature at runtime. So say that you want an AParser but the default AParser implementation doesn't support ParseFoo() but at runtime you want to give it ParseFoo() ability without defining this ahead of time?

If this is the case then I think you are going to have to consider a Decorator Design Pattern possibly along with your factory. With the Decorator, you will implement the functionality of the new features in their own classes and then your factory will return the decorator which simply wraps the BaseParser concrete class.

you can always use Obisoft.HSharp:

Semantic actions inhibit automatic propagation of attributes. This is obviously also the reason why the first version of the program didn't nead any for of adaptation for the MyResult struct.

So either

1. Stick to semantic actions¹ (dropping adapt-struct)

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