Tutorial by Examples: p

In some places in Common Lisp, a series of forms are evaluated in order. For instance, in the body of a defun or lambda, or the body of a dotimes. In those cases, writing multiple forms in order works as expected. In a few places, however, such as the then and else parts of an if expressions, onl...

The general purpose special operator progn is used for evaluating zero or more forms. The value of the last form is returned. For instance, in the following, (print 'hello) is evaluated (and its result is ignored), and then 42 is evaluated and its result (42) is returned: (progn (print 'hello...

Often times, it is helpful to evaluate multiple expressions and to return the result from the first or second form rather than the last. This is easy to accomplish using let and, for instance: (let ((form1-result form1)) form2 form3 ;; ... form-n-1 form-n form1-result) Because...

You can use npm install -g to install a package "globally." This is typically done to install an executable that you can add to your path to run. For example: npm install -g gulp-cli If you update your path, you can call gulp directly. On many OSes, npm install -g will attempt to writ...

This is a custom JAX-RS @Provider to use Gson as the JSON parser. The example also shows how to use custom Java 8 date/time converters. @Provider @Produces(MediaType.APPLICATION_JSON) @Consumes(MediaType.APPLICATION_JSON) public class JerseyServerGson implements MessageBodyWriter<O...

2005 The following iterates over the characters of the string s. It works similarly for looping over the elements of an array or a set, so long as the type of the loop-control variable (c, in this example) matches the element type of the value being iterated. program ForLoopOnString; {$APPTYPE ...

OpenCL is short for Open Computing Language. OpenCL is a Framework for parallel programming across heterogeneous platforms, called compute devices, ranging from CPUs over GPUs to more special platforms like FPGAs. OpenCL provides a standard interface for parallel computing on these compute devices b...

If you have a modern CPU or graphics card (GPU) inside your machine, chances are you have everything ready for first steps in OpenCL. Finding out if your processor is OpenCL capable can be usually done via the manufacturer's homepage, a good first start is the official documentation at https://www...

Every Windows Phone project contains App.cs class: public sealed partial class App : Application This class is your global application context. General Application class usage: App entry point, particularly for various activation contracts. Application lifecycle management. Application g...

Perl supports many kinds of loop constructs: for/foreach, while/do-while, and until. @numbers = 1..42; for (my $i=0; $i <= $#numbers; $i++) { print "$numbers[$i]\n"; } #Can also be written as foreach my $num (@numbers) { print "$num\n"; } The while loop ev...

// Get the reference to your ListView ListView listResults = (ListView) findViewById(R.id.listResults); // Set its adapter listResults.setAdapter(adapter); // Enable filtering in ListView listResults.setTextFilterEnabled(true); // Prepare your adapter for filtering adapter.setFilter...

Many tasks require elevated privileges. You can elevate user privileges to Administrator level for your batch runtime using a shortcut: Press alt+ and the batch file to a selected folder to create a shortcut. Right click and select "Properties". Select the "Shortcut&quo...

The following batch file will popup a UAC Prompt allowing you to accept elevated Administrator privileges for the batch session. Add your tasks code to :usercode section of the batch, so they run with elevated privileges. @echo off setlocal EnableDelayedExpansion :: test and acquire admin rights ...

In most scripting languages, if a function call fails, it may throw an exception and stop execution of the program. Bash commands do not have exceptions, but they do have exit codes. A non-zero exit code signals failure, however, a non-zero exit code will not stop execution of the program. This can...

Detailed instructions on getting database-design set up or installed.

Principal Component Analysis finds sequences of linear combinations of the features. The first linear combination maximizes the variance of the features (subject to a unit constraint). Each of the following linear combinations maximizes the variance of the features in the subspace orthogonal to that...

Detailed instructions on getting gis set up or installed.

The <cfparam> tag creates a variable if it does not already exist. You can assign a default value using the default attribute. This can be used if you want to create a variable, but don't want to overwrite it if it has been previously created elsewhere. Here the variable hasn't been set previ...

public class Producer { private static Random random = new Random((int)DateTime.UtcNow.Ticks); //produce the value that will be posted to buffer block public double Produce ( ) { var value = random.NextDouble(); Console.WriteLine($"Producing value: {value}...

We can draw a connection between the Haskell types and the natural numbers. This connection can be made assigning to every type the number of inhabitants it has. Finite union types For finite types, it suffices to see that we can assign a natural type to every number, based in the number of constr...