[antlr-interest] wildcard in tree grammar

[Oliver Zeigermann]

2008/11/27 Gavin Lambert <antlr at mirality.co.nz>:
> In other words (in vaguely ANTLR-like syntax):
>
>   wildtree : ANYNODE | ^(ANYNODE wildtree*) ;
>
>   .          => wild
>   ^(.)       => ANYNODE
>   ^(. FOO)   => ^(ANYNODE FOO)
>   ^(FOO .)   => ^(FOO wildtree)
>   ^(FOO . .) => ^(FOO wildtree wildtree)
>   ^(FOO .+)  => ^(FOO wildtree+)
>   ^(FOO .*)  => ^(FOO wildtree*)

Using these semantics my original rule

tree : ^(. tree* ) ;

would match any tree even if subtrees are single nodes only, right?

Oliver