Tutorial by Examples: d

Many modern Prolog systems are in continuous development and have added new features to address classic shortcomings of the language. Unfortunately, many Prolog textbooks and even teaching courses still introduce only the outdated prolog. This topic is intended to illustrate how modern Prolog has ov...

Traditionally Prolog performed arithmetic using the is and =:= operators. However, several current Prologs offer CLP(FD) (Constraint Logic Programming over Finite Domains) as a cleaner alternative for integer arithmetic. CLP(FD) is based on storing the constraints that apply to an integer value and ...

Some "classic" Prolog textbooks still use the confusing and error-prone failure-driven loop syntax where a fail construct is used to force backtracking to apply a goal to every value of a generator. For example, to print all numbers up to a given limit: fdl(X) :- between(1,X,Y), print(Y),...

Traditionally in Prolog, "functions" (with one output and bound inputs) were written as regular predicates: mangle(X,Y) :- Y is (X*5)+2. This can create the difficulty that if a function-style predicate is called multiple times, it is necessary to "daisy chain" temporary vari...

The dependencies for your projects are specified in a single text file called a Podfile. CocoaPods will resolve dependencies between libraries, fetch the resulting source code, then link it together in an Xcode workspace to build your project. Create a podfile # Next line contains target platf...

Try to run your code from the tool bar as shown below : In your code, if you have more than one function then, before running it you should mention the function you want to run with. For example : Alternatively, you can press ctrl + r from your keyboard to run the code. It will save the code f...

# Like any other ruby code, require gtk3 after installing from "gem install gtk3" require 'gtk3' # Like in Rails, you import working functions from a higher class, in this case the GTK Window class RubyApp < Gtk::Window # Calling the original method from GTK Window and redefinin...

int width = 256; //in pixels int height = 256; //in pixels BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_4BYTE_ABGR); //BufferedImage.TYPE_4BYTE_ABGR - store RGB color and visibility (alpha), see javadoc for more info Graphics g = image.createGraphics(); //draw w...

BufferedImage cat = ImageIO.read(new File("cat.jpg")); //read existing file //modify it Graphics g = cat.createGraphics(); g.setColor(Color.RED); g.drawString("Cat", 10, 10); g.dispose(); //now create a new image BufferedImage cats = new BufferedImage(256, 256, Buffere...

BufferedImage image = new BufferedImage(256, 256, BufferedImage.TYPE_INT_ARGB); //you don't have to use the Graphics object, you can read and set pixel color individually for (int i = 0; i < 256; i++) { for (int j = 0; j < 256; j++) { int alpha = 255; //don't forget this, or ...

Java applets are able to load different resources. But since they are running in the web browser of the client you need to make sure that these resources are accessible. Applets are not able to access client resources as the local file system. If you want to load resources from the same URL the App...

Common Lisp does not have interfaces in the sense that some languages (e.g., Java) do, and there is less need for that type of interface given that Common Lisp supports multiple inheritance and generic functions. However, the same type of patterns can be realized easily using mixin classes. This e...

Let's say we have a table team_person as below: +======+===========+ | team | person | +======+===========+ | A | John | +------+-----------+ | B | Smith | +------+-----------+ | A | Walter | +------+-----------+ | A | Louis | +------+-----------+ | C | ...

The unreal mode exploits two facts on how both Intel and AMD processors load and save the information to describe a segment. The processor caches the descriptor information fetched during a move in a selector register in protected mode. These information are stored in an architectural invisibl...

RENAME TABLE t TO t_old, t_copy TO t; No other sessions can access the tables involved while RENAME TABLE executes, so the rename operation is not subject to concurrency problems. Atomic Rename is especially for completely reloading a table without waiting for DELETE and load to finish: CREATE ...

A VIEW acts very much like a table. Although you can UPDATE a table, you may or may not be able to update a view into that table. In general, if the SELECT in the view is complex enough to require a temp table, then UPDATE is not allowed. Things like GROUP BY, UNION, HAVING, DISTINCT, and some su...

To install the software: After the download completes, run the installer. For Windows, the installer executable file has the .exe extension. Double-click the installer file to run it. For Linux platforms, the installer file has the .sh extension. For these platforms, you need to make ...

To run the software: After the download of the platform-independent ZIP file completes, extract it to any folder on your system. Run the executable file located in the netbeans/bin directory. Accept the License Agreement. Click Next. The NetBeans IDE installation starts. Note: If a compatib...

The ROLLUP operator is useful in generating reports that contain subtotals and totals. CUBE generates a result set that shows aggregates for all combinations of values in the selected columns. ROLLUP generates a result set that shows aggregates for a hierarchy of values in the selected col...

R contains a Date class, which is created with as.Date(), which takes a string or vector of strings, and if the date is not in ISO 8601 date format YYYY-MM-DD, a formatting string of strptime-style tokens. as.Date('2016-08-01') # in ISO format, so does not require formatting string ## [1] &quot...