Hi all. I'm trying to build a simple xhtml recognizer (for whitespace compression) in the purpose of learning antlr. Here's a sample of what I like to match :
<html xmlns="http://www.w3.org/1999/xhtml"; xml:lang="en" lang="en"> <head> <title> XHTML Example </title> </head> <body> <p> Please Choose a Day: <br /><br /> <select name="day"> <option selected="selected">Monday</option> <option>Tuesday</option> <option>Wednesday</option> </select> </p> </body> </html> This is the grammar : grammar Html; options { output=AST; ASTLabelType=CommonTree; } prog : tag_element * ; element : tag_element | text_element ; tag_element : open_tag element* close_tag | empty_tag ; open_tag: OPEN_TAG name attribute* CLOSE_TAG ; close_tag : OPEN_TAG '/' name CLOSE_TAG ; empty_tag : OPEN_TAG name '/' CLOSE_TAG ; attribute : namespace? ID '=' '"' (options{greedy=false;}: .)* '"' ; namespace : ID ':' ; name : ID ; text_element : (~(OPEN_TAG) | WS)+ ; ID : ('a'..'z'|'A'..'Z')+ ; INT : '0'..'9'+ ; NEWLINE : '\r'? '\n' ; WS : (' '|'\t'|'\n'|'\r')+ {skip();} ; OPEN_TAG : '<'; CLOSE_TAG : '>'; My problem is with the text_element rule. I'd like to match everything until the recognizer find a OPEN_TAG, including whitespaces. While the actuale rule work, this give me this error : [10:32:12] warning(200): Html.g:43:21: Decision can match input such as "WS" using multiple alternatives: 1, 2, 3 As a result, alternative(s) 3,2 were disabled for that input [10:32:12] warning(200): Html.g:43:21: Decision can match input such as "{CLOSE_TAG..ID, INT..':'}" using multiple alternatives: 1, 3 As a result, alternative(s) 3 were disabled for that input [10:32:12] error(201): Html.g:43:21: The following alternatives can never be matched: 2 How could I handle this case properly ? Regard, Kabnot List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "il-antlr-interest" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en -~----------~----~----~----~------~----~------~--~---
