This example from the undertow docs doesn't parse:

http://undertow.io/undertow-docs/undertow-docs-2.0.0/#textual-representation-of-handlers

path-template('/foobar') -> {
 redirect(/);
} else {
 path(/some-other-path) -> header(header=my-header,value=my-value)
}

The error is 

Error parsing predicated handler string unexpected token ->

The nested path() predicate causes the parsing error.  Removing the nested path() predicate will allow the example to work.