[antlr-interest] Error in 2.7.2

[Matthew Ford]

I downloaded 2.7.2 final.  There is an error in the ANTLR Parser

I am getting the following error
    [antlr] ANTLR Parser Generator   Version 2.7.2   1989-2003 jGuru.com
    [antlr] C:\temp\antlrTest\links.g:107: warning:lexical nondeterminism
between alts 1 and 2 of block upon
    [antlr] C:\temp\antlrTest\links.g:107:
k==1:'\t','\n','\u000c','\r',' '
    [antlr] C:\temp\antlrTest\links.g:107:     k==2:<end-of-token>

with (full code below)

protected
SCARF
 : WS // track line numbers while you scarf
 | . {}
 ;

while
protected
SCARF
 : WS // track line numbers while you scarf
 | .
 ;

gives no errors

matthew
----- Original Message -----
From: "Matthew Ford" <Matthew.Ford at forward.com.au>
To: <antlr-interest at yahoogroups.com>
Sent: Friday, May 30, 2003 10:33 PM
Subject: Error in 2.7.1 translator


> Hi
> When I add one action I get the error message.  I think this is an error
as
> the grammar has not changed.
>
>    [antlr] ANTLR Parser Generator   Version 2.7.1   1989-2000 jGuru.com
>     [antlr] C:\temp\antlrTest\links.g:107: warning: lexical nondeterminism
> upon
>     [antlr] C:\temp\antlrTest\links.g:107:  k==1:'\t','\n','\u000c','\r','
'
>     [antlr] C:\temp\antlrTest\links.g:107:  k==2:<end-of-token>
>     [antlr] C:\temp\antlrTest\links.g:107:  between alts 1 and 2 of block
>
> The .g file is shown below
> The only difference needed to generate the above error is to change
>
> protected
> SCARF
>  : WS // track line numbers while you scarf
>  | .  ;  // no action here and no errors
>
> TO
>
> protected
> SCARF
>  : WS // track line numbers while you scarf
>  | . {output.print("");}  // added this action to get errors
>  ;
>
>
> regards
> Matthew
> P.S. I will try this on 2.7.2 tomorrow.
>
>
> //link.g file
> {
> import java.util.Vector;
> import java.io.PrintStream;
> }
>
>
> /** Parse an entire html file, firing events to a single listener
>  *  for each image and href link encountered.  All tokens are
>  *  defined to skip so the lexer will continue scarfing until EOF.
>  */
> class ImageLinkExtractor extends Lexer;
> options {
>  caseSensitive=false;
>  k=2;
>  filter=SCARF;
>  charVocabulary='\3'..'\u0FFE';
> }
>
> {
>  PrintStream output = null;
>
>   String tableWidth="65";
>
>  public void setOutput(PrintStream out) {
>    output = out;
>  }
>
>  /** strip quotes from "..." or '...' strings */
>  public static String stripQuotes(String src) {
>   int h = src.indexOf('"');
>   if ( h==-1 ) h = src.indexOf('\'');
>   int t = src.lastIndexOf('"');
>   if ( t==-1 ) t = src.lastIndexOf('\'');
>   if ( h==-1 || t==-1 ) return src;
>   return src.substring(h+1,t);
>  }
> }
>
>
> IMG : ("<img" {output.print("<img");}
>        WS (ATTR)+
>     '>' {output.print(">");})
>     {$setType(Token.SKIP);}
>  ;
>
> protected
> ATTR
> options {
>  ignore=WS;
> }
>  : w:WORD '='
>   ( s:STRING // output handled below
>   | v:WORD {output.print(v.getText());}
>   )
>   { output.print(" "+w.getText()+"=");
>     if (v!=null) {
>      output.print(v.getText());
>    } else if (s!=null) {
>     String heightOrWidth = stripQuotes(s.getText());
>     if (( w.getText().equalsIgnoreCase("height") )
>       || ( w.getText().equalsIgnoreCase("width") ) ) {
>       int size = Integer.parseInt(heightOrWidth);
>       size++;
>       output.print("\""+size+"\"");
>     } else {
>       // some other attribute like src just output
>      output.print(s.getText()+"");
>     }
>    } else {
>      // s==null have output v above
>    }
>   }
>   ;
>
> /** Match until next whitespace; can be file, int, etc... */
> protected
> WORD: (
>    options {
>     generateAmbigWarnings=false;
>    }
>   : 'a'..'z' | '0'..'9' | '/' | '.' | '#' | '_'
>   )+
>  ;
>
> protected
> STRING
>  : '"' (~'"')* '"'
>  | '\'' (~'\'')* '\''
>  ;
>
>
> protected
> WS : ( ' ' {output.print(" ");}
>   | '\t' {output.print("\t");}
>   | '\f'  {output.print("\f");}
>   | ( "\r\n"  {output.print("\r\n");} // DOS
>    | '\r'   {output.print("\r");} // Macintosh
>    | '\n'   {output.print("\r");} // Unix (the right way)
>    )
>    { newline(); }
>   )
>   { //$setType(Token.SKIP);
>   }
>  ;
>
> protected
> SCARF
>  : WS // track line numbers while you scarf
>  | . {output.print("");}
>  ;
> ----------------------------------------------------
> Dr. Matthew.Ford
> Forward Computing & Control Pty. Ltd.
> www.forward.com.au
>


 

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