Search Results

Search found 12058 results on 483 pages for 'abstract syntax tree'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 34/483 | < Previous Page | 30 31 32 33 34 35 36 37 38 39 40 41  | Next Page >

  • Hierarchy inheritance

    - by reito
    I had faced the problem. In my C++ hierarchy tree I have two branches for entities of difference nature, but same behavior - same interface. I created such hierarchy trees (first in image below). And now I want to work with Item or Base classes independetly of their nature (first or second). Then I create one abstract branch for this use. My mind build (second in image below). But it not working. Working scheme seems (third in image below). It's bad logic, I think... Do anybody have some ideas about such hierarchy inheritance? How make it more logical? More simple for understanding? Image Sorry for my english - russian internet didn't help:) Update: You ask me to be more explicit, and I will be. In my project (plugins for Adobe Framemaker) I need to work with dialogs and GUI controls. In some places I working with WinAPI controls, and some other places with FDK (internal Framemaker) controls, but I want to work throw same interface. I can't use one base class and inherite others from it, because all needed controls - is a hierarchy tree (not one class). So I have one hierarchy tree for WinAPI controls, one for FDK and one abstract tree to use anyone control. For example, there is an Edit control (WinEdit and FdkEdit realization), a Button control (WinButton and FdkButton realization) and base entity - Control (WinControl and FdkControl realization). For now I can link my classes in realization trees (Win and Fdk) with inheritence between each of them (WinControl is base class for WinButton and WinEdit; FdkControl is base class for FdkButton and FdkEdit). And I can link to abstract classes (Control is base class for WinControl and FdkControl; Edit is base class for WinEdit and FdkEdit; Button is base class for WinButton and FdkButton). But I can't link my abstract tree - compiler swears. In fact I have two hierarchy trees, that I want to inherite from another one. Update: I have done this quest! :) I used the virtual inheritence and get such scheme (http://img12.imageshack.us/img12/7782/99614779.png). Abstract tree has only absolute abstract methods. All inheritence in abstract tree are virtual. Link from realization tree to abstract are virtual. On image shown only one realization tree for simplicity. Thanks for help!

    Read the article

  • Why I am getting Null from this statement. Query Syntax in C#

    - by Shantanu Gupta
    This is not working. Returns Null to dept_list. var dept_list = ((from map in DtMapGuestDepartment.AsEnumerable() where map.Field<Nullable<long>>("Guest_Id") == 174 select map.Field<Nullable<long>>("Department_id")).Distinct())as IEnumerable<DataRow>; DataTable dt = dept_list.CopyToDataTable(); //dept_list comes null here This works as desired. var dept_list = from map in DtMapGuestDepartment.AsEnumerable() where map.Field<Nullable<long>>("Guest_Id") == 174 select map; DataTable dt = dept_list.CopyToDataTable(); //when used like this runs correct. What mistake is being done by me here. ?

    Read the article

  • Pseudo LRU tree algorithm.

    - by patros
    A lot of descriptions of Pseudo LRU algorithms involve using a binary search tree, and setting flags to "point away" from the node you're searching for every time you access the tree. This leads to a reasonable approximation of LRU. However, it seems from the descriptions that all of the nodes deemed LRU would be leaf nodes. Is there a pseudo-LRU algorithm that deals with a static tree that will still perform reasonably well, while determining that non-leaf nodes are suitable LRU candidates?

    Read the article

  • gunit syntax for tree walker with a flat list of nodes

    - by Kaleb Pederson
    Here's a simple gunit test for a portion of my tree grammar which generates a flat list of nodes: objectOption walks objectOption: <<one:"value">> -> (one "value") Although you define a tree in ANTLR's rewrite syntax using a caret (i.e. ^(ROOT child...)), gunit matches trees without the caret, so the above represents a tree and it's not surprising that it fails: it's a flat list of nodes and not a tree. This results in a test failure: 1 failures found: test2 (objectOption walks objectOption, line17) - expected: (one \"value\") actual: one \"value\" Another option which seems intuitive is to leave off the parenthesis, like this: objectOption walks objectOption: <<one:"value">> -> one "value" But gunit doesn't like this syntax. It seems to result in a parse failure in the gunit grammar: line 17:20 no viable alternative at input 'one' line 17:24 missing ':' at 'value' line 0:-1 no viable alternative at input '<EOF>' java.lang.NullPointerException at org.antlr.gunit.OutputTest.getExpected(OutputTest.java:65) at org.antlr.gunit.gUnitExecutor.executeTests(gUnitExecutor.java:245) ... What is the correct way to match a flat tree?

    Read the article

  • Parsing a given binary tree using python?

    - by kaushik
    Parse a binary tree,referring to given set of features,answering decision tree question at each node to decide left child or right child and find the path to leaf node according to answer given to the decision tree.. input wil be a set of feature which wil help in answering the question at each level to choose the left or right half and the output will be the leaf node.. i need help in implementing this can anyone suggest methods?? Please answer... thanks in advance..

    Read the article

  • Psuedo LRU tree algorithm.

    - by patros
    A lot of descriptions of Pseudo LRU algorithms involve using a binary search tree, and setting flags to "point away" from the node you're searching for every time you access the tree. This leads to a reasonable approximation of LRU. However, it seems from the descriptions that all of the nodes deemed LRU would be leaf nodes. Is there a pseudo-LRU algorithm that deals with a static tree that will still perform reasonably well, while determining that non-leaf nodes are suitable LRU candidates?

    Read the article

  • Output of gcc -fdump-tree-original

    - by Job
    If I dump the code generated by GCC for a virtual destructor (with -fdump-tree-original), I get something like this: ;; Function virtual Foo::~Foo() (null) ;; enabled by -tree-original { <<cleanup_point <<< Unknown tree: expr_stmt (void) (((struct Foo *) this)->_vptr.Foo = &_ZTV3Foo + 8) >>> >>; } <D.20148>:; if ((bool) (__in_chrg & 1)) { <<cleanup_point <<< Unknown tree: expr_stmt operator delete ((void *) this) >>> >>; } My question is: where is the code after "<D.20148>:;" located? It is outside of the destructor so when is this code executed?

    Read the article

  • What is validating a binary search tree?

    - by dotnetdev
    I read on here of an exercise in interviews known as validating a binary search tree. How exactly does this work? What would one be looking for in validating a binary search tree? I have written a basic search tree, but never heard of this concept. Thanks

    Read the article

  • Level-order in Haskell

    - by brain_damage
    I have a structure for a tree and I want to print the tree by levels. data Tree a = Nd a [Tree a] deriving Show type Nd = String tree = Nd "a" [Nd "b" [Nd "c" [], Nd "g" [Nd "h" [], Nd "i" [], Nd "j" [], Nd "k" []]], Nd "d" [Nd "f" []], Nd "e" [Nd "l" [Nd "n" [Nd "o" []]], Nd "m" []]] preorder (Nd x ts) = x : concatMap preorder ts postorder (Nd x ts) = (concatMap postorder ts) ++ [x] But how to do it by levels? "levels tree" should print ["a", "bde", "cgflm", "hijkn", "o"]. I think that "iterate" would be suitable function for the purpose, but I cannot come up with a solution how to use it. Would you help me, please?

    Read the article

  • Design suggestion for expression tree evaluation with time-series data

    - by Lirik
    I have a (C#) genetic program that uses financial time-series data and it's currently working but I want to re-design the architecture to be more robust. My main goals are: sequentially present the time-series data to the expression trees. allow expression trees to access previous data rows when needed. to optimize performance of the data access while evaluating the expression trees. keep a common interface so various types of data can be used. Here are the possible approaches I've thought about: I can evaluate the expression tree by passing in a data row into the root node and let each child node use the same data row. I can evaluate the expression tree by passing in the data row index and letting each node get the data row from a shared DataSet (currently I'm passing the row index and going to multiple synchronized arrays to get the data). Hybrid: an immutable data set is accessible by all of the expression trees and each expression tree is evaluated by passing in a data row. The benefit of the first approach is that the data row is being passed into the expression tree and there is no further query done on the data set (which should increase performance in a multithreaded environment). The drawback is that the expression tree does not have access to the rest of the data (in case some of the functions need to do calculations using previous data rows). The benefit of the second approach is that the expression trees can access any data up to the latest data row, but unless I specify what that row is, I'll have to iterate through the rows and figure out which one is the last one. The benefit of the hybrid is that it should generally perform better and still provide access to the earlier data. It supports two basic "views" of data: the latest row and the previous rows. Do you guys know of any design patterns or do you have any tips that can help me build this type of system? Should I use a DataSet to hold and present the data, or are there more efficient ways to present rows of data while maintaining a simple interface? FYI: All of my code is written in C#.

    Read the article

  • Asp.Net tree view in SharePoint webpart- Input string error

    - by Faiz
    Hi All, I am facing a very strange issue. I have a SharePoint webpart that displays an asp.net tree view. It takes tree depth from a drop down. To improve performance of the tree view, i am setting the PopulateOnDemand property to true for the last level of the tree depth. For example, if i have a total of 10 levels in the data and the user selects tree depth as 3, then the third level data i set PopulateOnDemand to true. Now comes the strange part. When i click on the + image on the third level, and if there are children under that particular node then call back happens and node gets expanded. But if there no children for that particular node, then click + throws "Input string was not in the correct format" error. I have made sure that there is no server side error. Some things looks to be fishy when internet explorer is trying to bind construct the expanded node. Please let me know if any one faced similar issue or the resolution for the same? Thanks in advance

    Read the article

  • Example of tree.drop_mode with jQuery sortable anywhere

    - by fred
    Hello Everyone, I have a working tree of galleries next to a sortable list of image thumbnails. I've been vainly trying to set up the galleries tree so that users can add images to the galleries by dropping the sortable thumbnails on to the galleries tree. I've been told this requires drop_mode. All efforts to get it to work have failed and I can't really make heads or tails of the drop_mode documentation. I've sought out some working examples via Google of just such an application but have failed. Can anyone point me to a working example of either a draggable or sortable list that successfully drops on to a tree and passes along some parameters between the two? Thanks!

    Read the article

  • Adding UIComponent to both Canvas and Tree in Flex 3

    - by Chris M
    I currently am trying to add a custom class which subclasses UIComponent to both a tree and a canvas, but when I try to re-order the tree by dragging I get this error: TypeError: Error #1010: A term is undefined and has no properties. at mx.controls::Tree/get firstVisibleItem()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\controls\Tree.as:764] at flash.utils::ByteArray/writeObject() at flash.desktop::Clipboard/putSerialization() at flash.desktop::Clipboard/convertFlashFormat() at flash.desktop::Clipboard/setData() at mx.managers::NativeDragManagerImpl/doDrag()[C:\autobuild\3.2.0\frameworks\projects\airframework\src\mx\managers\NativeDragManagerImpl.as:282] at mx.managers::DragManager$/doDrag()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\managers\DragManager.as:243] at mx.controls.listClasses::ListBase/dragStartHandler()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\controls\listClasses\ListBase.as:9085] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at mx.core::UIComponent/dispatchEvent()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\core\UIComponent.as:9298] at mx.controls.listClasses::ListBase/mouseMoveHandler()[C:\autobuild\3.2.0\frameworks\projects\framework\src\mx\controls\listClasses\ListBase.as:8822] When I do not add the UIComponent to the canvas, this error does not occur, anyone have any knowledge as to why this happens?

    Read the article

  • Depth First Search Basics

    - by cam
    I'm trying to improve my current algorithm for the 8 Queens problem, and this is the first time I'm really dealing with algorithm design/algorithms. I want to implement a depth-first search combined with a permutation of the different Y values described here: http://en.wikipedia.org/wiki/Eight_queens_puzzle#The_eight_queens_puzzle_as_an_exercise_in_algorithm_design I've implemented the permutation part to solve the problem, but I'm having a little trouble wrapping my mind around the depth-first search. It is described as a way of traversing a tree/graph, but does it generate the tree graph? It seems the only way that this method would be more efficient only if the depth-first search generates the tree structure to be traversed, by implementing some logic to only generate certain parts of the tree. So essentially, I would have to create an algorithm that generated a pruned tree of lexigraphic permutations. I know how to implement the pruning logic, but I'm just not sure how to tie it in with the permutation generator since I've been using next_permutation. Is there any resources that could help me with the basics of depth first searches or creating lexigraphic permutations in tree form?

    Read the article

  • sql statement to Expression tree

    - by Joo Park
    I'm wondering how one would translate a sql string to an expression tree. Currently, in Linq to SQL, the expression tree is translated to a sql statement. How does on go the other way? How would you translate select * from books where bookname like '%The%' and year > 2008 into an expression tree in c#?

    Read the article

  • Any tips of how to handle hierarchical trees in relational model?

    - by George
    Hello all. I have a tree structure that can be n-levels deep, without restriction. That means that each node can have another n nodes. What is the best way to retrieve a tree like that without issuing thousands of queries to the database? I looked at a few other models, like flat table model, Preorder Tree Traversal Algorithm, and so. Do you guys have any tips or suggestions of how to implement a efficient tree model? My objective in the real end is to have one or two queries that would spit the whole tree for me. With enough processing i can display the tree in dot net, but that would be in client machine, so, not much of a big deal. Thanks for the attention

    Read the article

  • Eclipse RCP Preferences Dialog Tree Size

    - by nerduban
    In my RCP application, I'm trying to use the Eclipse preferences dialog. I'm adding extensions to the "org.eclipse.ui.preferencePages" and preparing related IWorkbenchPreferencePage implementations. My preference page names are a bit long, so that they are not totally visible on the left side tree of the preferences dialog. Dragging the sash bar to the right increases the width of this tree, but it is resetted after the program is closed and reopened. Is it possible to increase the default width of this tree?

    Read the article

  • When using Query Syntax in C# "Enumeration yielded no results". How to retrieve output

    - by Shantanu Gupta
    I have created this query to fetch some result from database. Here is my table structure. What exaclty is happening. DtMapGuestDepartment as Table 1 DtDepartment as Table 2 Are being used var dept_list= from map in DtMapGuestDepartment.AsEnumerable() where map.Field<Nullable<long>>("GUEST_ID") == DRowGuestPI.Field<Nullable<long>>("PK_GUEST_ID") join dept in DtDepartment.AsEnumerable() on map.Field<Nullable<long>>("DEPARTMENT_ID") equals dept.Field<Nullable<long>>("DEPARTMENT_ID") select dept.Field<string>("DEPARTMENT_ID"); I am performing this query on DataTables and expect it to return me a datatable. Here I want to select distinct department from Table 1 as well which will be my next quest. Please answer to that also if possible.

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 30 31 32 33 34 35 36 37 38 39 40 41  | Next Page >