[antlr-interest] AST rewrite

[Mark Volkmann]

I have the following rule in my parser grammar and it works just fine.
I don't know how though. Note how my rule matches "term" in two places
and I refer to both of them in my rewrite rule without assigning them
to variables.

polynomial[String fnt, String fvt]
  : term[$fnt, $fvt] (SIGN term[$fnt, $fvt])*
    -> ^(POLYNOMIAL term (SIGN term)*);

Why does this work? I thought I'd have to do something like this.

polynomial[String fnt, String fvt]
  : t1=term[$fnt, $fvt] (SIGN tn=term[$fnt, $fvt])*
    -> ^(POLYNOMIAL $t1 (SIGN $tn)*);

-- 
R. Mark Volkmann
Object Computing, Inc.