[antlr-interest] Unexpected ANTLR action

[Rich]

According to the "ANTLR Tree Construction" chapter of the antlr manual
"If no suffixes at all are specified in a grammar, then a Parser will
construct a linked-list of the tokens."  However, I'm not getting the
behavior I was expecting.  Consider the following grammar (grammar
simplified to protect the irrelevant):

class SimpleParser extends Parser;

options {
	buildAST = true;	
}

expr
	: id_expr ((DOT)? id_expr)*
	;

id_expr
	: ID
	;

When I test this parser with input "a b c d", I was expecting to get
the list (a b c d).  Instead, I just get "a".  What gives?  Thanks
alot everybody.

-Rich