Differentiate between XML breadthFirst() traversal and * navigation

[manouti]

The analogy between '*' and breadthFirst() traversal seems wrong. The former only traverses one level, while the latter searches through the next levels as well. See http://stackoverflow.com/questions/42985716/groovy-xml-tree-traversal-breadthfirst-method-using-as-syntactic-sugar:

def books = '''\
<response>
   <books>
      <book available="20" id="1">
         <title>foo</title>
         <author id="1">foo author</author>
      </book>
      <book available="14" id="2">
         <title>bar</title>
         <author id="2">bar author</author>
      </book>
   </books>
</response>'''

def response = new XmlSlurper().parseText(books)
def bk = response.'*'.find { node ->
   node.name() == 'book' && node['@id'].toInteger() == 2
}
assert bk.empty

whereas using breadthFirst() explicitly does what I expect both to do which is to do breadth-first traversal:

def books = '''\
<response>
   <books>
      <book available="20" id="1">
         <title>foo</title>
         <author id="1">foo author</author>
      </book>
      <book available="14" id="2">
         <title>bar</title>
         <author id="2">bar author</author>
      </book>
   </books>
</response>'''

def response = new XmlSlurper().parseText(books)
def bk = response.breadthFirst().find { node ->
   node.name() == 'book' && node['@id'].toInteger() == 2
}
assert bk.title == 'bar' // bk is no longer an empty list of children

[paulk-asert]

The shortcut for depthFirst() is '**' while the shortcut for children() is '*'. Obviously what is there is not quite right. I'll check shortly whether I think your changes capture everything that we need.

[paulk-asert]

I merged your changes with minor tweaks. Thanks, much appreciated!