[antlr-interest] Simple Grammar Question

[John Gardener]

    *Gerald*, hi;

    Thank you very much for your response;

    YES, you are right, I can see that: " Your NAME rule is consuming
    all tokens. "

    What I can not see is how to *correct this properly*?

    Thanks again,

    John

-------- Original Message  --------
Subject: Re: [antlr-interest] Simple Grammar Question
From: Gerald Rosenberg <gerald at certiv.net>
To: John Gardener <John.Gardener at carrotgarden.com>, antlr-interest at antlr.org
Date: Fri 16 Jan 2009 10:31:10 PM CST
> Your NAME rule is consuming all tokens. 
>
> The record rule fails to find a digit, recovers and finds a name,
> succeeds yet reports the exception.
>
>
> At 07:08 PM 1/16/2009, John Gardener wrote:
>>
>>     Hello;
>>
>>     I am stuck with simple grammar; any help is much welcomed;
>>
>>     I want to parse 2 term sentenses, such as:
>>     <1: single digit > <2: name containing letters and digits > EOF
>>
>>     Below comes:
>>     1) grammar
>>     2) test rig
>>     3) output
>>
>>     PROBLEM:
>>     Second term (name) seems to greedily consume whole input;
>>
>>     Please let me know what is the proper way to deal with this?
>>
>>     1) GRAMMAR
>>
>>     grammar Simple;  
>>
>>     options {
>>         language = Java;
>>     }
>>
>>     @parser::header {
>>         package simple;
>>         import static java.lang.System.out;
>>     }
>>
>>     @lexer::header{
>>       package simple;
>>       import static java.lang.System.out;
>>     }
>>
>>     // PARSER
>>
>>     record :
>>       digit name EOF
>>       { out.println( "+record: " +  $text );  };
>>
>>     digit : DIGIT
>>       { out.println( "+digit: " +  $text );  };
>>      
>>     name : NAME
>>       { out.println( "+name: " +  $text );  };
>>
>>
>>     // LEXER
>>
>>     DIGIT : '0'..'9'
>>       { out.println("+DIGIT: " + $text ); } ;
>>
>>     LETTER : 'A'..'Z'
>>       { out.println("+LETTER: " + $text ); } ;
>>
>>     NAME : ( LETTER | DIGIT ) + 
>>       { out.println("+NAME: " + $text ); } ;
>>
>>
>>     2) TEST RIG
>>
>>     package simple;
>>
>>     import java.io.ByteArrayInputStream;
>>
>>     import org.antlr.runtime.ANTLRInputStream;
>>     import org.antlr.runtime.CommonTokenStream;
>>
>>     import static java.lang.System.out;
>>
>>     public class SimpleTest {
>>
>>         public static void main(String[] args) throws Exception {
>>
>>             String record = "3B5A";
>>
>>             ByteArrayInputStream stream = new ByteArrayInputStream(record
>>                     .getBytes());
>>
>>             ANTLRInputStream input = new ANTLRInputStream(stream);
>>
>>             SimpleLexer lexer = new SimpleLexer(input);
>>
>>             CommonTokenStream tokens = new CommonTokenStream(lexer);
>>
>>             SimpleParser parser = new SimpleParser(tokens);
>>
>>             parser.record();
>>
>>             out.println(record);
>>
>>         }
>>
>>     }
>>
>>
>>     3) TEST OUTPUT
>>
>>     +DIGIT: 3
>>     +LETTER: 3B
>>     +DIGIT: 3B5
>>     +LETTER: 3B5A
>>     +NAME: 3B5A
>>     line 1:0 missing DIGIT at '3B5A'
>>     +digit: null
>>     +name: 3B5A
>>     +record: 3B5A
>>     3B5A
>>
>>
>>     Thank you,
>>
>>     John
>>
>>
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