1 # $Id: Node.pm,v 1.3 2006-10-11 14:34:21 mike Exp $
3 package ZOOM::IRSpy::Node;
12 ZOOM::IRSpy::Node - node in a tree of names
16 $node1 = new ZOOM::IRSpy::Node("LowLevelTest");
17 $node2 = new ZOOM::IRSpy::Node("AnotherTest");
18 $node3 = new ZOOM::IRSpy::Node("Aggregate", $node1, $node2);
19 $node = new ZOOM::IRSpy::Node("Main", $node3);
21 $subnode = $node->select("0:1");
22 die "oops" if $subnode->name() ne "AnotherTest";
26 IRSpy maintains a declarative hierarchy of the tests that each
27 connection may be required to perform, which it compiles recursively
28 from the C<subtests()> method of the top-level test and each of its
29 subtests, sub-subtests, etc. The result of this compilation is a
30 hierarchy represented by a tree of C<ZOOM::IRSpy::Node> objects.
32 Note that each node contains a test I<name>, not an actual test
33 object. Test objects are different, and are implemented by the
34 C<ZOOM::IRSpy::Test> class its subclasses. In fact, there is nothing
35 test-specific about the Node module: it can be used to build
36 hierarchies of anything.
38 You can't do much with a node. Each node carries a name string and a
39 list of its subnodes, both of which are specified at creation time and
40 can be retrieved by accessor methods; trees can be pretty-printed, but
41 that's really only useful for debugging; and finally, nodes can be
42 selected from a tree using an address, which is a bit like a totally
47 $node = new ZOOM::IRSpy::Node($name, @subnodes);
49 Creates a new node with the name specified as the first argument of
50 the constructor. If further arguments are provided, they are taken to
51 be existing nodes that become subnodes of the new one. Once a node
52 has been created, neither its name nor its list of subnodes can be
59 my($name, @subnodes) = @_;
62 subnodes => \@subnodes,
68 print "Node is called '", $node->name(), "'\n";
70 Returns the name of the node.
81 @nodes = $node->subnodes();
82 print "Node has ", scalar(@nodes), " subnodes\n";
84 Returns a list of the subnodes of the node.
90 return @{ $this->{subnodes} };
97 Pretty-prints the node and, recursively, all its children. The
98 parameter is the level of indentation to use in printing the node;
99 this method recursively invokes itself with higher levels.
107 print "\t" x $level, $this->name();
108 if (my @sub = $this->subnodes()) {
110 foreach my $sub (@sub) {
111 $sub->print($level+1);
113 print "\t" x $level, "}";
120 $sameNode = $node->select("");
121 $firstSubNode $node->select("0");
122 $secondSubNode $node->select("1");
123 $deepNode $node->select("0:3:2");
125 Returns a specified node from the tree of which C<$node> is the root,
126 or an undefined value if the specified node does not exist. The sole
127 argument is the address of the node to be returned, which consists of
128 zero or more colon-separated components. Each component is an
129 integer, a zero-based index into the subnodes at that level. Example
136 The node itself, i.e. the root of the tree.
140 Subnode number 0 (i.e. the first subnode) of the root.
144 Subnode number 1 (i.e. the second subnode) of the root.
148 Subnode 2 of subnode 3 of subnode zero of the root (i.e. the third
149 subnode of the fourth subnode of the first subnode of the root).
159 my @sub = $this->subnodes();
160 if ($address eq "") {
162 } elsif (my($head, $tail) = $address =~ /(.*):(.*)/) {
163 return $sub[$head]->select($tail);
165 return $sub[$address];
176 Mike Taylor, E<lt>mike@indexdata.comE<gt>
178 =head1 COPYRIGHT AND LICENSE
180 Copyright (C) 2006 by Index Data ApS.
182 This library is free software; you can redistribute it and/or modify
183 it under the same terms as Perl itself, either Perl version 5.8.7 or,
184 at your option, any later version of Perl 5 you may have available.