PathMatcher filters that are applied in order to a list of nodes that are provided by a GraphModel object.
@author tugrul@google.com (Tugrul Ince)
This class inherits from SlashExpression; it is used in the common case where the SlashExpression is known to return nodes rather than atomic values.
This class is not responsible for sorting the results into document order or removing duplicates. That is done by a DocumentSorter expression which is wrapped around the path expression. However, this class does contain the logic for deciding statically whether the DocumentSorter is needed or not.
b" that exists below a node named "a", regardless of where node "a" occurs. Again, neither node may have any same-name-sibilings. With these simple examples, you can probably discern the most important rules. First, the '*' is a wildcard character that matches any character or sequence of characters in a node's name (or index if appearing in between square brackets), and can be used in conjunction with other characters (e.g., "*.txt").
Second, square brackets (i.e., '[' and ']') are used to match a node's same-name-sibiling index. You can put a single non-negative number or a comma-separated list of non-negative numbers. Use '0' to match a node that has no same-name-sibilings, or any positive number to match the specific same-name-sibling.
Third, combining two delimiters (e.g., "//") matches any sequence of nodes, regardless of what their names are or how many nodes. Often used with other patterns to identify nodes at any level matching other patterns. Three or more sequential slash characters are treated as two.
Many input paths can be created using just these simple rules. However, input paths can be more complicated. Here are some more examples:
| Input Path | Description |
|---|---|
| /a/(b|c|d) | Match children of the top level node "a" that are named "a", "b" or "c ". None of the nodes may have same-name-sibling indexes. |
| /a/b[c/d] | Match node "b" child of the top level node "a", when node "b" has a child named " c", and "c" has a child named "d". Node "b " is the selected node, while nodes "b" and "b" are used as criteria but are not selected. |
| /a(/(b|c|d|)/e)[f/g/@something] | Match node "/a/b/e", "/a/c/e", "/a/d/e", or "/a/e " when they also have a child "f" that itself has a child "g" with property "something". None of the nodes may have same-name-sibling indexes. |
These examples show a few more advanced rules. Parentheses (i.e., '(' and ')') can be used to define a set of options for names, as shown in the first and third rules. Whatever part of the selected node's path appears between the parentheses is captured for use within the output path. Thus, the first input path in the previous table would match node " /a/b", and "b" would be captured and could be used within the output path using "$1", where the number used in the output path identifies the parentheses.
Square brackets can also be used to specify criteria on a node's properties or children. Whatever appears in between the square brackets does not appear in the selected node.
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