[antlr-interest] npe in AssignTokenTypesBehavior.aliasTokenIDsAndLiterals

[Mark Taylor]

Hi,

It appears the tokens 'up' and 'down' are invalid somehow. The input
below gives the following exception 'down', I believe the same thing
happens for 'up'.  This is using antlr-3.4-complete.jar

input:

grammar test_down;

tokens {
       //WHILE = 'while';
       DOWN = 'down';
}

//test : WHILE;
test : DOWN;


c:\nbprojects\antlr>java -jar antlr-3.4-complete.jar test_down.g
error(10):  internal error: test_down.g : java.lang.NullPointerException
org.antlr.tool.AssignTokenTypesBehavior.aliasTokenIDsAndLiterals(AssignTokenTypesBehavior.java:281)
org.antlr.tool.AssignTokenTypesBehavior.defineTokens(AssignTokenTypesBehavior.java:216)
org.antlr.tool.CompositeGrammar.assignTokenTypes(CompositeGrammar.java:346)
org.antlr.Tool.process(Tool.java:462)
org.antlr.Tool.main(Tool.java:93)