Tutorial by Examples: du

Each group ends with a line separator. If each item in your menu has its own group you will achieve the desired graphical output. It will work only if your different groups have different android:id. Also, in menu.xml remember to mention android:checkable="true" for single item and android...

When using the interactive interpreter, you might want to reload a module. This can be useful if you're editing a module and want to import the newest version, or if you've monkey-patched an element of an existing module and want to revert your changes. Note that you can't just import the module ag...

In Java, it's too "easy" to create many String instances which are not needed. That and other reasons might cause your program to have lots of Strings that the GC is busy cleaning up. Some ways you might be creating String instances: myString += "foo"; Or worse, in a loop or...

<svg width="400px" height="200px"> <text x="1em, 2em, 3em, 4em, 5em" y="3em, 4em, 5em"> Individually Spaced Text </text> </svg> The Text element supports individual placement of letters by accepting an array of values for...

Categorical products In category theory, the product of two objects X, Y is another object Z with two projections: π₁ : Z → X and π₂ : Z → Y; such that any other two morphisms from another object decompose uniquely through those projections. In other words, if there exist f₁ : W → X and f₂ : W →...

reduce(_:combine:) can be used in order to combine the elements of a sequence into a single value. It takes an initial value for the result, as well as a closure to apply to each element – which will return the new accumulated value. For example, we can use it to sum an array of numbers: let numbe...

If you’re switching to Jekyll from another blogging system, Jekyll’s importers can help you with the move. Most methods listed on this page require read access to the database from your old system to generate posts for Jekyll. Each method generates .markdown posts in the _posts directory based on th...

from __future__ import print_function import multiprocessing def countdown(count): while count > 0: print("Count value", count) count -= 1 return if __name__ == "__main__": p1 = multiprocessing.Process(target=countdown, args=(10,)) ...

This attribute is used to describe the product that this particular assembly is for. Multiple assemblies can be components of the same product, in which case they can all share the same value for this attribute. [assembly: AssemblyProduct("MyProduct")]

Ruby has three types of objects: Classes and modules which are instances of class Class or class Module. Instances of classes. Singleton Classes. Each object has a class which contains its methods: class Example end object = Example.new object.class # => Example Example.class # ...

The SilverStripe Grid Field Extensions Module has some very nice features to enhance the basic GridField... GridFieldAddExistingSearchButton - a more advanced search form for adding items GridFieldAddNewInlineButton - builds on GridFieldEditableColumns to allow inline creation of records. GridF...

Intuition The categorical product of two types A and B should contain the minimal information necessary to contain inside an instance of type A or type B. We can see now that the intuitive coproduct of two types should be Either a b. Other candidates, such as Either a (b,Bool), would contain a part...

Modules have a one-to-one correspondence with source files. The module name is, by default, the file name with the path and extension stripped off, and can be set explicitly with the module declaration. The ModuleDeclaration sets the name of the module and what package it belongs to. If absent, the...

Julia provides macros to simplify distributing computation across multiple machines or workers. For instance, the following computes the sum of some number of squares, possibly in parallel. function sumofsquares(A) @parallel (+) for i in A i ^ 2 end end Usage: julia> sumo...

Overview Create a queue that we can send a message to. Oracle will notify our stored procedure that a message has been enqueued and should be worked. We'll also add some subprograms we can use in an emergency to stop messages from being deqeued, allow dequeuing again, and run a simple batch job t...

Recursive type Discriminated unions can be recursive, that is they can refer to themselves in their definition. The prime example here is a tree: type Tree = | Branch of int * Tree list | Leaf of int As an example, let's define the following tree: 1 2 5 3 4 We can defi...

Microcontrollers use pins to interact with the rest of the circuit. These pins will usually be one of input / output pins, vin or ground. I/O pins can be simple digital I/O pins, or they can have some special carachteristics like being able to vary the voltage of their output using pulse width modul...

pip is your friend when you need to install any package from the plethora of choices available at the python package index (PyPI). pip is already installed if you're using Python 2 >= 2.7.9 or Python 3 >= 3.4 downloaded from python.org. For computers running Linux or another *nix with a native...

For example, types for SI units have been standardized in the F# core library, in Microsoft.FSharp.Data.UnitSystems.SI. Open the appropriate sub-namespace, UnitNames or UnitSymbols, to use them. Or, if only a few SI units are required, they can be imported with type aliases: /// Seconds, the SI uni...

If you don't have permissions to install perl modules, you may still install them manually, indicating a custom path where you've got writing permissions. Fist, download and unzip module archive: wget module.tar.gz tar -xzf module.tar.gz cd module Then, if the module distribution contains a M...