[antlr-interest] ANTLR v4 progress

[Terence Parr]

Just passing along an example HTML subset lexer/parser using ANTLR v4; thanks to  debugging and moral support from Oliver Zeigermann, we got the code generation and runtime support working sufficiently to use the following grammars.   generate some really nice code indeed. You will note that, except for the enhancement of the lexer modes, the grammars are backward compatible with v3 :)

I still have a long way to go, but it's looking more & more useful (only does LL(1) code generation at this point).

Ter
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lexer grammar HTMLLexer;

TAG_START : '<' {pushMode(INSIDE);} ;

COMMENT : '<!--' .* '-->' {skip();} ;

TEXT : ~'<'+ ;

mode INSIDE;

TAG_STOP : '>' {popMode();} ;

END_TAG : '/' ID '>' {popMode();} ;

ID : ('A'..'Z'|'a'..'z'|'0'..'9'|'_'|'#')+ ;

EQ : '=' ;

STRING : '"' .* '"'
       ;

WS : ' '+ {skip();} ;

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parser grammar HTMLParser;

options { tokenVocab=HTMLLexer; }

file : ( TAG_START (starttag | endtag) | TEXT)+ EOF ;

starttag : ID attr* TAG_STOP ;

attr : ID (EQ (ID|STRING))? ;

endtag
	:	 END_TAG
	;