[antlr-interest] Re: upgrade question

[nagii5]

> An excellent question.  The answer is yes, but that should start 
> indicating another solution is better.  You could have the lexer 
match 
> <anytag> and </anytag> and then use a stack to make sure they line 
up :)
> 
> Ter

Thanks, Terence
I cant have the lexer match </anytag> for me because i dont 
want other rules to modify the output buffer between
<anytag>  and </anytag>
I need a way to specify that whatever comes between the tags 
must be untouched. 

now, if i try k = 14 ( thats the length of the longest such tag i 
look for) antlr.Tool hangs at ( going into an infinite loop)
So i guess im doing something which i shudnt!

"main" prio=5 tid=0x235360 nid=0x690 runnable [0x6e000..0x6fc34]
        at java.lang.Object.clone(Native Method)
        at antlr.Lookahead.clone(Lookahead.java:96)
        at antlr.LLkAnalyzer.look(LLkAnalyzer.java:944)
        at antlr.LLkAnalyzer.look(LLkAnalyzer.java:773)
        at antlr.RuleRefElement.look(RuleRefElement.java:49)


Coming back to the original question :

protected SAMPLE: {! LA(1)=='<' && LA(2)=='/' && LA(3)== 'a' &&
                    LA(4)=='n' && LA(5)=='y' && LA(6)=='t' &&
                    LA(7)=='a' && LA(8)=='g' } ? NL_CTR )*

protected NL_CTR: c:. {if (c=='\n') newline(); buff.append((char)c);}

antlr2.7.1 generates the following code for the SAMPLE rule,

protected final void mSAMPLE(boolean _createToken) .etc 
etc...TokenStreamException {
  int _ttype; Token _token=null; int _begin=text.length();
  _ttype = SAMPLE;
  int _saveIndex;
  {
	_loop274:
	do {
		if (((LA(1) >= '\u0003' && LA(1) <= '\uffff'))) {
			mNL_CTR(false);
		}
		else {
			break _loop274;
		}
		
	} while (true);
	}
	if ( _createToken && _token==null && _ttype!=Token.SKIP ) {
		_token = makeToken(_ttype);
		_token.setText(new String(text.getBuffer(), _begin, 
text.length()-_begin));
	}
	_returnToken = _token;
}
----------------------------------------------------
With 2.7.0 the method looks like: (omitting the common stuff)
-----------------------------------

if ((((LA(1) >= '\3' && LA(1) <= '\uffff')))&&(! LA(1)=='<' && LA(2)
=='/' && LA(3)== 'a' && LA(4)=='n' && LA(5)=='y' && LA(6)=='t' &&
  LA(7)=='a' && LA(8)=='g' )) {
				mNL_CTR(false);
	}

---------------------------------

Is there a reason for 2.7.1 to not add the extra
check  
namely 
&&(! LA(1)=='<' && LA(2)=='/' && LA(3)== 'a' && LA(4)=='n' && LA(5)
=='y' && LA(6)=='t' &&   LA(7)=='a' && LA(8)=='g' )) {


thanks
nagesh


 

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