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• Web-based SVG or JavaScript Org Chart or Tree Graph Plotting Visualization API

  - by asoltys

  Hi, I'm looking to build an interactive web-based org chart for a large organization. I somewhat like the interface at ancestry.com where you can hover over people and pan/zoom around and click on different nodes to make them the root. Ideally, I'd like it if people could belong to multiple organizational entities like committees, working groups, etc. In other words the API should support graphs in general, not just trees. I'd like to be able to visually explode each organizational substructure into substituents by clicking on it, with a nice animation of the employees ballooning or spilling out so you can really interactively drill down through the organization. I found http://code.google.com/apis/visualization/documentation/gallery/orgchart.html but it looks a bit rudimentary. I know there are desktop tools like OrgPlus and Visio that can build static charts but I'm really looking for a free, web-based API with open standards-based output like SVG or HTML5 Canvas elements rather than Flash or some proprietary output. Something I can embed into a custom web application and style myself. Something interactive.

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• Directory tree in a Resource without extraction...

  - by Corelgott

  Hi all, i am looking for a way to store a complete directory including sub directories in an application's resource and not have to extract it to use it. Details: We would like to use GeckoFx (Gecko as C# Component) in one of our applications. GeckoFX needs the XUL-Runner and needs to find it's folder structure We have some other data which I would not prefer to extracted to the customer's pc; At least not onto something persistent like a hdd... Getting the complete directory into the resources is not that kind of a big deal. Compress to one file and done. But not writing it to the disk to use it is something else. I have a strong dislike against temp folders and such things. Would anything like a RAM drive be possible? Some part of the RAM beeing mounted? Does something like this even exist as a lib, or would this only be possible by a device driver? Any thoughts on this? Thanks in advance! Corelgott

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• creating decision tree based troubleshooting documentation?

  - by Joseph

  We troubleshoot a lot of server and network issues and follow a loose set of steps on what to do in different cases. With more and more people and responsibility, the need for standardization is needed so we don't miss something. I know I could accomplish what I want using flowcharts, but I'd like to do something similar to a "Choose Your Own Adventure" style. I think this is pretty much the same as what support call centers seem to do. Are there any tools to make creating such documentation easier? I'm looking for a web based approach if possible.

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• creating decision tree based troubleshooting documentation?

  - by Joseph

  We troubleshoot a lot of server and network issues and follow a loose set of steps on what to do in different cases. With more and more people and responsibility, the need for standardization is needed so we don't miss something. I know I could accomplish what I want using flowcharts, but I'd like to do something similar to a "Choose Your Own Adventure" style. I think this is pretty much the same as what support call centers seem to do. Are there any tools to make creating such documentation easier? I'm looking for a web based approach if possible.

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• Zipping folder with absolute path without keeping tree of folders

  - by Preston

  I am attempting to use the zip -r command to zip a folder which includes two files. I need to pass the absolute path of the folder with two files (/path/to/my/files/), which is causing all of the folders to be zipped with it, where as I only need the last folder (files/) and its contents to be zipped, so that when the file is unzipped, there is only one folder and the two files within it. How can I modify the command to be able to pass the absolute paths in the arguments while keeping only the last folder?

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• Make symlink on Windows of whole tree without modifying the original folder

  - by DarkGhostHunter

  I'm trying to do this: make a symlink of a whole directory "C:/Master", in different folders like "C:\Projects\Alpha\", "C:\Projects\Beta\" an so on. "Master" directory usually changes in files and data. I work on the "Projects/*", where every project folder uses the "Master" files, but every one has new files in them. Let's say, I point to the car engine in every project folder, and inside them I add different kind of wheels. The problem I'm having, as a Windows 8 user, is that symlinks (junction) acts as a window to "Master" - I'm not allowed to add any file inside. I looking a way to reference the entire "Master" directory, and add new files - not edit any of the "Master" ones. It's as described here, but on Windows.

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• How to zip and rename a directory tree

  - by Kev

  I have a lot of music in a lot of directories: ./artist1/album1/*.mp3 ./artist1/album2/*.mp3 ./artist1/album3/*.mp3 ./artist2/album1/*.mp3 ./artist2/album2/*.mp3 ./artist3/album1/*.mp3 ./artist3/album2/*.mp3 ... ... How can I zip them to this: ./artist1/album1/*.mp3 => ./artist1-album1.tar.gz ./artist1/album2/*.mp3 => ./artist1-album2.tar.gz ./artist1/album3/*.mp3 => ./artist1-album3.tar.gz ./artist2/album1/*.mp3 => ./artist2-album1.tar.gz ./artist2/album2/*.mp3 => ./artist2-album2.tar.gz ./artist3/album1/*.mp3 => ./artist3-album1.tar.gz ./artist3/album2/*.mp3 => ./artist3-album2.tar.gz ... ... I'd like one-line-command or a simple script.

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• Output directory tree as XML

  - by Jamie

  HI all, Is there a linux command which will output the structure of a given directory as XML? if there is, that would be awesome. Thanks very much

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• Fastest security check of file tree on NFS

  - by fungs

  I am currently experiencing very bad performance using the following on an NFS network folder: time find . | while read f; do test -L "$f" && f=$(readlink -m $f); grp="$(stat -c %G $f)"; perm="$(stat -c %A $f)"; done Question 1) Within the loop permissions are checked using the variables grp and perm. Is there a way to lower the amount of disc I/O for these kind of checks over the network (e.g. read all meta data at once using find)? Question 2) It seems like the NFS isn't tuned very well, the same operation on a similar network link via SSHFS take only one third of the time. All parameters are auto-negotiated. Any suggestions?

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• VMware vSwitches and spanning tree

  - by dunxd

  I have two redundant core switches I want to connect to a new vSwitch I am setting up on a VMware ESX host. The switch will have two physical NICs each of which will connect to one of the core switches. The core switches are connected. If this was a physical switch, I would worry about connecting it to both core switches, because this would create a network loop. Do I need to worry about this for a VMware virtual switch? VMware's documentation says it is not possible to connect two vSwitches in a loop, therefore STP is not required. However, I am worried about connecting two physical switches together via a vSwitch.

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• Most efficient way of creating tree from adjacency list

  - by Jeff Meatball Yang

  I have an adjacency list of objects (rows loaded from SQL database with the key and it's parent key) that I need to use to build an unordered tree. It's guaranteed to not have cycles. This is taking wayyy too long (processed only ~3K out of 870K nodes in about 5 minutes). Running on my workstation Core 2 Duo with plenty of RAM. Any ideas on how to make this faster? public class StampHierarchy { private StampNode _root; private SortedList<int, StampNode> _keyNodeIndex; // takes a list of nodes and builds a tree // starting at _root private void BuildHierarchy(List<StampNode> nodes) { Stack<StampNode> processor = new Stack<StampNode>(); _keyNodeIndex = new SortedList<int, StampNode>(nodes.Count); // find the root _root = nodes.Find(n => n.Parent == 0); // find children... processor.Push(_root); while (processor.Count != 0) { StampNode current = processor.Pop(); // keep a direct link to the node via the key _keyNodeIndex.Add(current.Key, current); // add children current.Children.AddRange(nodes.Where(n => n.Parent == current.Key)); // queue the children foreach (StampNode child in current.Children) { processor.Push(child); nodes.Remove(child); // thought this might help the Where above } } } } public class StampNode { // properties: int Key, int Parent, string Name, List<StampNode> Children }

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• What does the \- mean in the mvn dependency tree output

  - by Calm Storm

  Hi, I tried doing a mvn dependency:tree and I get a tree of dependencies. The output looks like below. I want to know what is the "-" symbol that is shown at times and the "+-" symbol for other dependencies (it doesnt seem to be the scope) My actual question is, My project depends on many modules which internally depends on many spring artifacts. There are a few version clashes. I want to upgrade all spring related libraries to say the latest one (2.6.x or above). What is the preferred way to do this? Should I declare all the deps spring-context, spring-support (and 10 other artifacts) in my pom.xml and point them to 2.6.x ? Is there any other better method ? [INFO] +- com.xxxx:yyy-jar:jar:1.0-SNAPSHOT:compile [INFO] | +- com.xxxx:zzz-commons:jar:1.0-SNAPSHOT:compile [INFO] | | +- org.springframework:spring-dao:jar:2.0.7:compile [INFO] | | +- org.springframework:spring-jdbc:jar:2.0.7:compile [INFO] | | +- org.springframework:spring-web:jar:2.0.7:compile [INFO] | | +- org.springframework:spring-support:jar:2.0.7:compile [INFO] | | +- net.sf.ehcache:ehcache:jar:1.2:compile [INFO] | | +- commons-collections:commons-collections:jar:3.2:compile [INFO] | | +- aspectj:aspectjweaver:jar:1.5.3:compile [INFO] | | +- betex-commons:betex-commons:jar:5.5.1-2:compile [INFO] | | \- javax.servlet:servlet-api:jar:2.4:compile [INFO] | +- org.springframework:spring-beans:jar:2.0.7:compile [INFO] | +- org.springframework:spring-jmx:jar:2.0.7:compile [INFO] | +- org.springframework:spring-remoting:jar:2.0.7:compile [INFO] | +- org.apache.cxf:cxf-rt-core:jar:2.0.2-incubator:compile [INFO] | | +- org.apache.cxf:cxf-api:jar:2.0.2-incubator:compile [INFO] | | | +- org.apache.geronimo.specs:geronimo-activation_1.1_spec:jar:1.0-M1:compile [INFO] | | | +- org.codehaus.woodstox:wstx-asl:jar:3.2.1:compile [INFO] | | | +- org.apache.neethi:neethi:jar:2.0.2:compile [INFO] | | | \- org.apache.cxf:cxf-common-schemas:jar:2.0.2-incubator:compile

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• How to minimize total cost of shortest path tree

  - by Michael

  I have a directed acyclic graph with positive edge-weights. It has a single source and a set of targets (vertices furthest from the source). I find the shortest paths from the source to each target. Some of these paths overlap. What I want is a shortest path tree which minimizes the total sum of weights over all edges. For example, consider two of the targets. Given all edge weights equal, if they share a single shortest path for most of their length, then that is preferable to two mostly non-overlapping shortest paths (fewer edges in the tree equals lower overall cost). Another example: two paths are non-overlapping for a small part of their length, with high cost for the non-overlapping paths, but low cost for the long shared path (low combined cost). On the other hand, two paths are non-overlapping for most of their length, with low costs for the non-overlapping paths, but high cost for the short shared path (also, low combined cost). There are many combinations. I want to find solutions with the lowest overall cost, given all the shortest paths from source to target. Does this ring any bells with anyone? Can anyone point me to relevant algorithms or analogous applications? Cheers!

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• Binary Search Tree - Postorder logic

  - by daveb

  I am looking at implementing code to work out binary search tree. Before I do this I was wanting to verify my input data in postorder and preorder. I am having trouble working out what the following numbers would be in postorder and preorder I have the following numbers 4, 3, 14 ,8 ,1, 15, 9, 5, 13, 10, 2, 7, 6, 12, 11, that I am intending to put into an empty binary tree in that order. The order I arrived at for the numbers in POSTORDER is 2, 1, 6, 3, 7, 11, 12, 10, 9, 8, 13, 15, 14, 4. Have I got this right? I was wondering if anyone here would be able to kindly verify if the postorder sequence I came up with is indeed the correct sequence for my input i.e doing left subtree, right subtree and then root. The order I got for pre order (Visit root, do left subtree, do right subtree) is 4, 3, 1, 2, 5, 6, 14 , 8, 7, 9, 10, 12, 11, 15, 13. I can't be certain I got this right. Very grateful for any verification. Many Thanks

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• ANTLR Tree Grammar and StringTemplate Code Translation

  - by Behrooz Nobakht

  I am working on a code translation project with a sample ANTLR tree grammar as: start: ^(PROGRAM declaration+) -> program_decl_tmpl(); declaration: class_decl | interface_decl; class_decl: ^(CLASS ^(ID CLASS_IDENTIFIER)) -> class_decl_tmpl(cid={$CLASS_IDENTIFIER.text}); The group template file for it looks like: group My; program_decl_tmpl() ::= << *WHAT?* >> class_decl_tmpl(cid) ::= << public class <cid> {} >> Based on this, I have these questions: Everything works fine apart from that what I should express in WHAT? to say that a program is simply a list of class declarations to get the final generated output? Is this approach averagely suitable for not so a high-level language? I have also studied ANTLR Code Translation with String Templates, but it seems that this approach takes much advantage of interleaving code in tree grammar. Is it also possible to do it as much as possible just in String Templates?

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• Confused about definition of a 'median' when constructing a kd-Tree

  - by user352636

  Hi there. Im trying to build a kd-tree for searching through a set of points, but am getting confused about the use of 'median' in the wikipedia article. For ease of use, the wikipedia article states the pseudo-code of kd-tree construction as: function kdtree (list of points pointList, int depth) { if pointList is empty return nil; else { // Select axis based on depth so that axis cycles through all valid values var int axis := depth mod k; // Sort point list and choose median as pivot element select median by axis from pointList; // Create node and construct subtrees var tree_node node; node.location := median; node.leftChild := kdtree(points in pointList before median, depth+1); node.rightChild := kdtree(points in pointList after median, depth+1); return node; } } I'm getting confused about the "select median..." line, simply because I'm not quite sure what is the 'right' way to apply a median here. As far as I know, the median of an odd-sized (sorted) list of numbers is the middle element (aka, for a list of 5 things, element number 3, or index 2 in a standard zero-based array), and the median of an even-sized array is the sum of the two 'middle' elements divided by two (aka, for a list of 6 things, the median is the sum of elements 3 and 4 - or 2 and 3, if zero-indexed - divided by 2.). However, surely that definition does not work here as we are working with a distinct set of points? How then does one choose the correct median for an even-sized list of numbers, especially for a length 2 list? I appreciate any and all help, thanks! -Stephen

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• Hide the last children of an XML data provider (not to be displayed in mx:Tree)

  - by Andree

  Hi there! I have an hierachical XML data, and I want to display it as a tree. The XML data is something like this: <services> <service name="TestService" endpoint=""> <method name="sayHi"> <parameter name="firstName" /> <parameter name="lastName" /> </method> <method name="sayGoodbye"> <parameter name="firstName" /> <parameter name="lastName" /> </method> </service> <service name="AnotherTestService"> <method name="getName" /> <method name="setName"> <parameter name="name" /> </method> </service> </services> However, I don't want to display the last elements (parameters) in the tree because, well, it is not meant to be displayed, but still it has to be there. Any advice on how can I achieve that? I am thinking of either extending DefaultDataDescriptor or create a class which implement ITreeDataDescriptor. Which approach will be suitable in this case?

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• problem in creating a php tree menu

  - by Mac Taylor

  hi mates im writing a tree menu for my categories in php and i wonder how can i code it correctly ! this is my table in database " |----topicid------topicname--------parent | |---- 1 ------ News -------- 0 | |---- 2 ------ sport -------- 1 | |---- 3 ------ games -------- 1 | |---- 4 ------ PES -------- 3 | so now for showing it like a tree i did try but not worked : $result = mysql_query("SELECT * FROM Topics ORDER BY topicid"); while ($row = mysql_fetchrow($result)) { $id = intval($row['topicid']); $title = filter($row['topicname'], "nohtml"); $parent = $row['parent'] ; if ($parent==0) { $menu_item .= "<li><span class='folder'><a title = \"$alt\" href=\"modules.php?name=News&amp;new_topic=$id\">$title</a></span></li>"; }else { $result = mysql_query("SELECT * FROM ".$prefix."_Topics where parent='$id' ORDER BY topicid"); while ($row = mysql_fetchrow($result)) { $id = intval($row['topicid']); $title = filter($row['topicname'], "nohtml"); $parent = $row['parent'] ; $menu_item .= " <ul><li><span class='file'><a title = \"$alt\" href=\"modules.php?name=News&amp;new_topic=$id\">$title</a></span></li></ul>"; } } i dont know how to solve this

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• Pythagoras tree with g2d

  - by owca

  I'm trying to build my first fractal (Pythagoras Tree): in Java using Graphics2D. Here's what I have now : import java.awt.*; import java.awt.geom.*; import javax.swing.*; import java.util.Scanner; public class Main { public static void main(String[] args) { int i=0; Scanner scanner = new Scanner(System.in); System.out.println("Give amount of steps: "); i = scanner.nextInt(); new Pitagoras(i); } } class Pitagoras extends JFrame { private int powt, counter; public Pitagoras(int i) { super("Pythagoras Tree."); setSize(1000, 1000); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setVisible(true); powt = i; } private void paintIt(Graphics2D g) { double p1=450, p2=800, size=200; for (int i = 0; i < powt; i++) { if (i == 0) { g.drawRect((int)p1, (int)p2, (int)size, (int)size); counter++; } else{ if( i%2 == 0){ //here I must draw two squares } else{ //here I must draw right triangle } } } } @Override public void paint(Graphics graph) { Graphics2D g = (Graphics2D)graph; paintIt(g); } So basically I set number of steps, and then draw first square (p1, p2 and size). Then if step is odd I need to build right triangle on the top of square. If step is even I need to build two squares on free sides of the triangle. What method should I choose now for drawing both triangle and squares ? I was thinking about drawing triangle with simple lines transforming them with AffineTransform but I'm not sure if it's doable and it doesn't solve drawing squares.

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• Use SQL to clone a tree structure represented in a database

  - by AmoebaMan17

  Given a table that represents a hierarchical tree structure and has three columns ID (Primary Key, not-autoincrementing) ParentGroupID SomeValue I know the lowest most node of that branch, and I want to copy that to a new branch with the same number of parents that also need to be cloned. I am trying to write a single SQL INSERT INTO statement that will make a copy of every row that is of the same main has is part one GroupID into a new GroupID. Example beginning table: ID | ParentGroupID | SomeValue ------------------------ 1 | -1 | a 2 | 1 | b 3 | 2 | c Goal after I run a simple INSERT INTO statement: ID | ParentGroupID | SomeValue ------------------------ 1 | -1 | a 2 | 1 | b 3 | 2 | c 4 | -1 | a-cloned 5 | 4 | b-cloned 6 | 5 | c-cloned Final tree structure +--a (1) | +--b (2) | +--c (3) | +--a-cloned (4) | +--b-cloned (5) | +--c-cloned (6) The IDs aren't always nicely spaced out as this demo data is showing, so I can't always assume that the Parent's ID is 1 less than the current ID for rows that have parents. Also, I am trying to do this in T-SQL (for Microsoft SQL Server 2005 and greater). This feels like a classic exercise that should have a pure-SQL answer, but I'm too used to programming that my mind doesn't think in relational SQL.

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• Tree iterator, can you optimize this any further?

  - by Ron

  As a follow up to my original question about a small piece of this code I decided to ask a follow up to see if you can do better then what we came up with so far. The code below iterates over a binary tree (left/right = child/next ). I do believe there is room for one less conditional in here (the down boolean). The fastest answer wins! The cnt statement can be multiple statements so lets make sure this appears only once The child() and next() member functions are about 30x as slow as the hasChild() and hasNext() operations. Keep it iterative <-- dropped this requirement as the recursive solution presented was faster. This is C++ code visit order of the nodes must stay as they are in the example below. ( hit parents first then the children then the 'next' nodes). BaseNodePtr is a boost::shared_ptr as thus assignments are slow, avoid any temporary BaseNodePtr variables. Currently this code takes 5897ms to visit 62200000 nodes in a test tree, calling this function 200,000 times. void processTree (BaseNodePtr current, unsigned int & cnt ) { bool down = true; while ( true ) { if ( down ) { while (true) { cnt++; // this can/will be multiple statesments if (!current->hasChild()) break; current = current->child(); } } if ( current->hasNext() ) { down = true; current = current->next(); } else { down = false; current = current->parent(); if (!current) return; // done. } } }

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• Permuting output of a tree of closures

  - by yan

  This a conceptual question on how one would implement the following in Lisp (assuming Common Lisp in my case, but any dialect would work). Assume you have a function that creates closures that sequentially iterate over an arbitrary collection (or otherwise return different values) of data and returns nil when exhausted, i.e. (defun make-counter (up-to) (let ((cnt 0)) (lambda () (if (< cnt up-to) (incf cnt) nil)))) CL-USER> (defvar gen (make-counter 3)) GEN CL-USER> (funcall gen) 1 CL-USER> (funcall gen) 2 CL-USER> (funcall gen) 3 CL-USER> (funcall gen) NIL CL-USER> (funcall gen) NIL Now, assume you are trying to permute a combinations of one or more of these closures. How would you implement a function that returns a new closure that subsequently creates a permutation of all closures contained within it? i.e.: (defun permute-closures (counters) ......) such that the following holds true: CL-USER> (defvar collection (permute-closures (list (make-counter 3) (make-counter 3)))) CL-USER> (funcall collection) (1 1) CL-USER> (funcall collection) (1 2) CL-USER> (funcall collection) (1 3) CL-USER> (funcall collection) (2 1) ... and so on. The way I had it designed originally was to add a 'pause' parameter to the initial counting lambda such that when iterating you can still call it and receive the old cached value if passed ":pause t", in hopes of making the permutation slightly cleaner. Also, while the example above is a simple list of two identical closures, the list can be an arbitrarily-complicated tree (which can be permuted in depth-first order, and the resulting permutation set would have the shape of the tree.). I had this implemented, but my solution wasn't very clean and am trying to poll how others would approach the problem. Thanks in advance.

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• PHP: Convert <ul> <li> Tree HTML tag to an array

  - by marknt15

  Hi, I'm using jsTree and I need to convert this HTML tag tree code <ul> <li> to a PHP array. The jsTree HTML tag will be passed to PHP to be parsed and store in a structured tree PHP array(see below for the PHP array structure). Additional question: Is my desired PHP array structure good or you can suggest a good structure? I'm open for suggestions. Thanks in advance :) Cheers, Mark jsTree Screenshot: HTML Tree String: <ul class="ltr"> <li id="phtml_1" class=" open"> <a style="" class=" " href="#"><ins>&nbsp;</ins>Folder 1</a> <ul> <li class="leaf" id="phtml_2"> <a style="" class=" " href="#"><ins>&nbsp;</ins>Child 1.1</a> </li> <li class="open" id="phtml_3"> <a style="" class=" " href="#"><ins>&nbsp;</ins>Folder 1.1</a> <ul> <li class="leaf last" rel="default"> <a href="" style="" class=" "><ins>&nbsp;</ins>Child 1.1.1</a> </li> </ul> </li> <li class="last open" rel="default"> <a href="" style="" class=" "><ins>&nbsp;</ins>Folder 1.2</a> <ul> <li class="leaf" rel="default"> <a href="" style="" class=" "><ins>&nbsp;</ins>Child 1.2.1</a> </li> <li class="leaf last" rel="default"> <a href="" style="" class=" "><ins>&nbsp;</ins>Child 1.2.2</a> </li> </ul> </li> </ul> </li> <li id="phtml_5" class="file open"> <a style="" class=" " href="#"><ins>&nbsp;</ins>Folder 2</a> <ul> <li class="leaf" rel="default"> <a href="" style="" class=" "><ins>&nbsp;</ins>Child 2.1</a> </li> <li class="leaf last" rel="default"> <a href="" style="" class="clicked"><ins>&nbsp;</ins>Child 2.2</a> </li> </ul> </li> <li class="leaf last" rel="default"> <a href="" style="" class=" "><ins>&nbsp;</ins>Outer Child</a> </li> </ul> PHP Array Structure: <?php $tree_array = array( 'Folder 1' => array( 'Child 1.1', 'Folder 1.1' => array( 'Child 1.1.1' ), 'Folder 1.2' => array( 'Child 1.2.1', 'Child 1.2.2' ), ), 'Folder 2' => array( 'Child 2.1', 'Child 2.2' ), 'Outer Child' ); echo '<pre>',print_r($tree_array),'</pre>'; ?> PHP print_r Output: Array ( [Folder 1] => Array ( [0] => Child 1.1 [Folder 1.1] => Array ( [0] => Child 1.1.1 ) [Folder 1.2] => Array ( [0] => Child 1.2.1 [1] => Child 1.2.2 ) ) [Folder 2] => Array ( [0] => Child 2.1 [1] => Child 2.2 ) [0] => Outer Child )

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• Boost::Spirit::Qi autorules -- avoiding repeated copying of AST data structures

  - by phooji

  I've been using Qi and Karma to do some processing on several small languages. Most of the grammars are pretty small (20-40 rules). I've been able to use autorules almost exclusively, so my parse trees consist entirely of variants, structs, and std::vectors. This setup works great for the common case: 1) parse something (Qi), 2) make minor manipulations to the parse tree (visitor), and 3) output something (Karma). However, I'm concerned about what will happen if I want to make complex structural changes to a syntax tree, like moving big subtrees around. Consider the following toy example: A grammar for s-expr-style logical expressions that uses autorules... // Inside grammar class; rule names match struct names... pexpr %= pand | por | var | bconst; pand %= lit("(and ") >> (pexpr % lit(" ")) >> ")"; por %= lit("(or ") >> (pexpr % lit(" ")) >> ")"; pnot %= lit("(not ") >> pexpr >> ")"; ... which leads to parse tree representation that looks like this... struct var { std::string name; }; struct bconst { bool val; }; struct pand; struct por; struct pnot; typedef boost::variant<bconst, var, boost::recursive_wrapper<pand>, boost::recursive_wrapper<por>, boost::recursive_wrapper<pnot> > pexpr; struct pand { std::vector<pexpr> operands; }; struct por { std::vector<pexpr> operands; }; struct pnot { pexpr victim; }; // Many Fusion Macros here Suppose I have a parse tree that looks something like this: pand / ... \ por por / \ / \ var var var var (The ellipsis means 'many more children of similar shape for pand.') Now, suppose that I want negate each of the por nodes, so that the end result is: pand / ... \ pnot pnot | | por por / \ / \ var var var var The direct approach would be, for each por subtree: - create pnot node (copies por in construction); - re-assign the appropriate vector slot in the pand node (copies pnot node and its por subtree). Alternatively, I could construct a separate vector, and then replace (swap) the pand vector wholesale, eliminating a second round of copying. All of this seems cumbersome compared to a pointer-based tree representation, which would allow for the pnot nodes to be inserted without any copying of existing nodes. My question: Is there a way to avoid copy-heavy tree manipulations with autorule-compliant data structures? Should I bite the bullet and just use non-autorules to build a pointer-based AST (e.g., http://boost-spirit.com/home/2010/03/11/s-expressions-and-variants/)?

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• Why am I getting a " instance has no attribute '__getitem__' " error?

  - by Kevin Yusko

  Here's the code: class BinaryTree: def __init__(self,rootObj): self.key = rootObj self.left = None self.right = None root = [self.key, self.left, self.right] def getRootVal(root): return root[0] def setRootVal(newVal): root[0] = newVal def getLeftChild(root): return root[1] def getRightChild(root): return root[2] def insertLeft(self,newNode): if self.left == None: self.left = BinaryTree(newNode) else: t = BinaryTree(newNode) t.left = self.left self.left = t def insertRight(self,newNode): if self.right == None: self.right = BinaryTree(newNode) else: t = BinaryTree(newNode) t.right = self.right self.right = t def buildParseTree(fpexp): fplist = fpexp.split() pStack = Stack() eTree = BinaryTree('') pStack.push(eTree) currentTree = eTree for i in fplist: if i == '(': currentTree.insertLeft('') pStack.push(currentTree) currentTree = currentTree.getLeftChild() elif i not in '+-*/)': currentTree.setRootVal(eval(i)) parent = pStack.pop() currentTree = parent elif i in '+-*/': currentTree.setRootVal(i) currentTree.insertRight('') pStack.push(currentTree) currentTree = currentTree.getRightChild() elif i == ')': currentTree = pStack.pop() else: print "error: I don't recognize " + i return eTree def postorder(tree): if tree != None: postorder(tree.getLeftChild()) postorder(tree.getRightChild()) print tree.getRootVal() def preorder(self): print self.key if self.left: self.left.preorder() if self.right: self.right.preorder() def inorder(tree): if tree != None: inorder(tree.getLeftChild()) print tree.getRootVal() inorder(tree.getRightChild()) class Stack: def __init__(self): self.items = [] def isEmpty(self): return self.items == [] def push(self, item): self.items.append(item) def pop(self): return self.items.pop() def peek(self): return self.items[len(self.items)-1] def size(self): return len(self.items) def main(): parseData = raw_input( "Please enter the problem you wished parsed.(NOTE: problem must have parenthesis to seperate each binary grouping and must be spaced out.) " ) tree = buildParseTree(parseData) print( "The post order is: ", + postorder(tree)) print( "The post order is: ", + postorder(tree)) print( "The post order is: ", + preorder(tree)) print( "The post order is: ", + inorder(tree)) main() And here is the error: Please enter the problem you wished parsed.(NOTE: problem must have parenthesis to seperate each binary grouping and must be spaced out.) ( 1 + 2 ) Traceback (most recent call last): File "C:\Users\Kevin\Desktop\Python Stuff\Assignment 11\parseTree.py", line 108, in main() File "C:\Users\Kevin\Desktop\Python Stuff\Assignment 11\parseTree.py", line 102, in main tree = buildParseTree(parseData) File "C:\Users\Kevin\Desktop\Python Stuff\Assignment 11\parseTree.py", line 46, in buildParseTree currentTree = currentTree.getLeftChild() File "C:\Users\Kevin\Desktop\Python Stuff\Assignment 11\parseTree.py", line 15, in getLeftChild return root[1] AttributeError: BinaryTree instance has no attribute '__getitem__'

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