Start ANTLR project with Maven

http://www.antlr.org/wiki/display/ANTLR3/Building+ANTLR+Projects+with+Maven

http://www.eclipse.org/m2e/
Download m2e
http://www.eclipse.org/m2e/download/

dave@dave antlr-maven]$ mvn archetype:generate -B -DarchetypeGroupId=org.antlr
 -DarchetypeArtifactId=antlr3-maven-archetype
 -DarchetypeVersion=3.3-1 
 -DgroupId=dave.antlr
 -DartifactId=java-tree-walker
 -Dversion=1.0 
-Dpackage=dave.antlr 
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Maven Stub Project (No POM) 1
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] >>> maven-archetype-plugin:2.1:generate (default-cli) @ standalone-pom >>>
[INFO] 
[INFO] <<< maven-archetype-plugin:2.1:generate (default-cli) @ standalone-pom <<<
[INFO] 
[INFO] --- maven-archetype-plugin:2.1:generate (default-cli) @ standalone-pom ---
[INFO] Generating project in Batch mode
[INFO] Archetype repository missing. Using the one from [org.antlr:antlr3-maven-archetype:3.4] found in catalog remote
Downloading: http://repo1.maven.org/maven2/org/antlr/antlr3-maven-archetype/3.3-1/antlr3-maven-archetype-3.3-1.jar
Downloaded: http://repo1.maven.org/maven2/org/antlr/antlr3-maven-archetype/3.3-1/antlr3-maven-archetype-3.3-1.jar (11 KB at 34.4 KB/sec)
Downloading: http://repo1.maven.org/maven2/org/antlr/antlr3-maven-archetype/3.3-1/antlr3-maven-archetype-3.3-1.pom
Downloaded: http://repo1.maven.org/maven2/org/antlr/antlr3-maven-archetype/3.3-1/antlr3-maven-archetype-3.3-1.pom (3 KB at 6.0 KB/sec)
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Archetype: antlr3-maven-archetype:3.3-1
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: groupId, Value: davedave@dave antlr-maven]$ mvn archetype:generate -B -DarchetypeGroupId=org.antlr -DarchetypeArtifactId=antlr3-maven-archetype -DarchetypeVersion=3.3-1  -DgroupId=dave.antlr -DartifactId=java-tree-walker -Dversion=1.0 -Dpackage=dave.antlr 
[INFO] Scanning for projects...
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building Maven Stub Project (No POM) 1
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] >>> maven-archetype-plugin:2.1:generate (default-cli) @ standalone-pom >>>
[INFO] 
[INFO] <<< maven-archetype-plugin:2.1:generate (default-cli) @ standalone-pom <<<
[INFO] 
[INFO] --- maven-archetype-plugin:2.1:generate (default-cli) @ standalone-pom ---
[INFO] Generating project in Batch mode
[INFO] Archetype repository missing. Using the one from [org.antlr:antlr3-maven-archetype:3.4] found in catalog remote
Downloading: http://repo1.maven.org/maven2/org/antlr/antlr3-maven-archetype/3.3-1/antlr3-maven-archetype-3.3-1.jar
Downloaded: http://repo1.maven.org/maven2/org/antlr/antlr3-maven-archetype/3.3-1/antlr3-maven-archetype-3.3-1.jar (11 KB at 34.4 KB/sec)
Downloading: http://repo1.maven.org/maven2/org/antlr/antlr3-maven-archetype/3.3-1/antlr3-maven-archetype-3.3-1.pom
Downloaded: http://repo1.maven.org/maven2/org/antlr/antlr3-maven-archetype/3.3-1/antlr3-maven-archetype-3.3-1.pom (3 KB at 6.0 KB/sec)
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Archetype: antlr3-maven-archetype:3.3-1
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: groupId, Value: dave.antlr
[INFO] Parameter: artifactId, Value: java-tree-walker
[INFO] Parameter: version, Value: 1.0
[INFO] Parameter: package, Value: dave.antlr
[INFO] Parameter: packageInPathFormat, Value: dave/antlr
[INFO] Parameter: package, Value: dave.antlr
[INFO] Parameter: version, Value: 1.0
[INFO] Parameter: groupId, Value: dave.antlr
[INFO] Parameter: artifactId, Value: java-tree-walker
[INFO] project created from Archetype in dir: /usr/app/project/antlr-maven/java-tree-walker
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4.303s
[INFO] Finished at: Sun Feb 26 10:40:25 CET 2012
[INFO] Final Memory: 7M/17M
[INFO] ------------------------------------------------------------------------

[dave@dave java-tree-walker]$ cat >dave.dmo
Keyser Soze  ;
2 + 3;

java -jar target/java-tree-walker-1.0-jar-with-dependencies.jar dave.dmo

java -jar target/java-tree-walker-1.0-jar-with-dependencies.jar -dot dave.dmo

Tree traversal

http://en.wikipedia.org/wiki/Tree_traversal
http://en.wikipedia.org/wiki/Breadth-first_search
http://en.wikipedia.org/wiki/Depth-first_search

Tree traversal in various languages
http://rosettacode.org/wiki/Tree_traversal#Java

Algorithms
http://algs4.cs.princeton.edu/home/
Graphs
http://algs4.cs.princeton.edu/40graphs/
Directed Graphs

http://algs4.cs.princeton.edu/42directed/

Java Data Structure: A Generic Tree

http://sujitpal.blogspot.com/2006/05/java-data-structure-generic-tree.html

Generic Node

public class Node<T> {
 
    public T data;
    public List<Node<T>> children;
    public List<Node<T>> parents;

Non-generic node

package dave;

/**
 * Non-generic subclass of Node<String>
 */
public class DaveNode extends Node<String> {
    public DaveNode() {
        super();
    }
}

Walk using stack

 /**
   *   
   * @param element
   * @return set of all nodes
   */
  public List<Node<T>> walk(Node<T> element){
      
      List<Node<T>> out = new ArrayList<Node<T>>();
      
      Queue<Node<T>> q = new LinkedList<Node<T>>();
      q.add(element);
      
      while(!q.isEmpty()){
          Node<T> x = q.poll();
          out.add(x);
          
          for(Node<T> child : x.getChildren()){
              q.add(child);
          }
      }
      
      return out;
      
  }

Walk from bottom up

  /**
   *   
   * @param element
   * @return set of all upper nodes
   */
  public Collection<Node<T>> pathBottomUp(Node<T> element){
      
      Set<Node<T>> out = new LinkedHashSet<Node<T>>();
      
      Queue<Node<T>> q = new LinkedList<Node<T>>();
      q.add(element);
      
      while(!q.isEmpty()){
          Node<T> x = q.poll();
          out.add(x);
          
          for(Node<T> parent : x.getParents()){
              q.add(parent);
          }
      }
      
      return out;
      
  }

Construct tree

package dave;


public class WalkTree {

    public static void main(String[] args) {
        
        DaveTree daveTree = new DaveTree();
        
        DaveNode daveNode = getDaveNode("1");
        
        DaveNode daveNode11 = getDaveNode("1.1");
        DaveNode daveNode12 = getDaveNode("1.2");
        DaveNode daveNode13 = getDaveNode("1.3");
        
        DaveNode daveNode131 = getDaveNode("1.3.1");
        DaveNode daveNode132 = getDaveNode("1.3.2");
        
        daveNode.addChild(daveNode11);
        daveNode.addChild(daveNode12);
        daveNode.addChild(daveNode13);
        
        daveNode12.addChild(daveNode131);
        
        daveNode13.addChild(daveNode131);
        daveNode13.addChild(daveNode132);
        
                
        daveTree.setRootElement(daveNode);
        
        System.out.println(daveTree.toList());
                
        Node<String> root = daveTree.getRootElement();
        
        System.out.println("walk:" + daveTree.walk(root));
        
        System.out.println("pathBottomUp:" +daveTree.pathBottomUp(daveNode131));

    }
    
    private static DaveNode getDaveNode(String profileName){
        
        DaveNode daveNode = new DaveNode();
        
        daveNode.setData(profileName);
        
        return daveNode;
        
    }

}

Program output

[{1,[1.1,1.2,1.3]}, {1.1,[]}, {1.2,[1.3.1]}, {1.3.1,[]}, {1.3,[1.3.1,1.3.2]}, {1.3.1,[]}, {1.3.2,[]}]
walk:[{1,[1.1,1.2,1.3]}, {1.1,[]}, {1.2,[1.3.1]}, {1.3,[1.3.1,1.3.2]}, {1.3.1,[]}, {1.3.1,[]}, {1.3.2,[]}]
pathBottomUp:[{1.3.1,[]}, {1.2,[1.3.1]}, {1.3,[1.3.1,1.3.2]}, {1,[1.1,1.2,1.3]}]