Isn’t this example wrong?  From admin/notes/tree-sitter/starter-guide

>     (match NODE-TYPE PARENT-TYPE NODE-FIELD
>            NODE-INDEX-MIN NODE-INDEX-MAX)
> 
>     => checks everything. If an argument is nil, don’t match that. Eg,
>     (match nil nil TYPE) is the same as (parent-is TYPE)

Seems like (match nil TYPE) would be the same as (parent-is TYPE)