[antlr-interest] Help me the chemmestry forumla grammer?

[Jun Tsai]

hi all.
I want to parse a chemestry forumla.such as:
A2(B3)2C3  => A2B6C3
A2(AB3)2C3 =>A4B6C3
A(CB3)2C3 =>A1B6C5

How to do it?

I use :
parser:

entry : (atom)+
      ;
atom : (c:CHAR n:NUM)
	{System.out.println("c:"+c.getText()+" ");}
	| (LPAREN entry RPAREN n:NUM)
	{
		System.out.println("okay "+n.getText());
	
	}

Lexer:

NUM :('0'..'9')*;


Thanks.
Jun Tsai
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