Create a PathMatcher.
Create a PathMatcher. expr must be a '/'
delimited path where each
segment is either a legal Path segment or:
- the wildcard string "*"
which matches any single segment
- a variable capture string of the form "{foo}"
which captures the value
of the matched segment into the variable named foo.
Captured variables can be used in substitution patterns: occurrences of
"{foo}"
will be replaced with foo's value.