[antlr-interest] antlr: beginner question...

[pady]

Started using antlr this weekend...so please bear my lack of understanding 
( i did buy terence's book and am on page 70... )...

I wrote my first grammar...cut & paste from terence's java grammar...a 
subset just to handle if-else statements...

When I generate java from this ( using antlrworks also ), I get the 
following warnings which I dont understand - can somebody explain...

[14:29:59] warning(200): gwf.g:10:34: Decision can match input such as 
"'else'" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
[14:30:00] warning(200): C:\projects\antlr\gwf\gwf.g:10:34: Decision can 
match input such as "'else'" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input


what are the alternatives ? i cannot figure out how someone can get to 
'else' without going through just the 2nd alternative of "statement" rule 
below ? I have also attached the complete grammar ( not sure if this mailing 
list allows attachments... )



Grammar:


prog
 : statement+
 ;


statement
 :  statementExpression ';'
 | 'if' boolExpression statement (options {k=1;}:'else' statement)?
 | '{' statement* '}'
 ;

boolExpression
 : '(' expression ')'
 ;

statementExpression
 :  function '(' expressionList ')'
 |  Identifier('.' Identifier)* assignmentOperator expression
 ;

function
 : 'sendEmail'
 | 'loadData'
 | 'loadAllUsers'
 | 'loadUsersFromRole'
 ;

expressionList
    :   expression (',' expression)*
    ;

...
...


Thx

-- pady 
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