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[^0-9a-zA-Z] This will match all characters that are neither numbers nor letters (alphanumerical characters). If the underscore character _ is also to be negated, the expression can be shortened to: [^\w] Or: \W In the following sentences: Hi, what's up? I can't wait for 2017!...

If you have an instance of a generic type but for some reason don't know the specific type, you might want to determine the generic arguments that were used to create this instance. Let's say someone created an instance of List<T> like that and passes it to a method: var myList = new List&lt...

Suppose we want to receive a function as a parameter, we can do it like this: function foo(otherFunc: Function): void { ... } If we want to receive a constructor as a parameter: function foo(constructorFunc: { new() }) { new constructorFunc(); } function foo(constructorWithParams...

pip assists in creating requirements.txt files by providing the freeze option. pip freeze > requirements.txt This will save a list of all packages and their version installed on the system to a file named requirements.txt in the current folder.

pip assists in creating requirements.txt files by providing the freeze option. pip freeze --local > requirements.txt The --local parameter will only output a list of packages and versions that are installed locally to a virtualenv. Global packages will not be listed.

Access the nth element of a list (zero-based): list = [1 .. 10] firstElement = list !! 0 -- 1 Note that !! is a partial function, so certain inputs produce errors: list !! (-1) -- *** Exception: Prelude.!!: negative index list !! 1000 -- *** Exception: Prelude.!!: inde...

In the timeline of any DisplayObject that is attached as a descendant of the display tree, you can utilise the root property. This property points to the main timeline in the case of no custom document class, or the document class if you do define one. Because root is typed DisplayObject, the compi...

A list of recognised color keyword names can be found in the W3C Recommendation for SVG. <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <circle r="30" cx="100" cy="100" fill="red" stroke=&qu...

Because LINQ uses deferred execution, we can have a query object that doesn't actually contain the values, but will return the values when evaluated. We can thus dynamically build the query based on our control flow, and evaluate it once we are finished: IEnumerable<VehicleModel> BuildQuery(i...

Python has a variety of command-line switches which can be passed to py. These can be found by performing py --help, which gives this output on Python 3.4: Python Launcher usage: py [ launcher-arguments ] [ python-arguments ] script [ script-arguments ] Launcher arguments: -2 : Launch ...

Postfix increment X++ will add 1 to x var x = 42; x++; Console.WriteLine(x); // 43 Postfix decrement X-- will subtract one var x = 42 x--; Console.WriteLine(x); // 41 ++x is called prefix increment it increments the value of x and then returns x while x++ returns the value of x and the...

Introduce environment variable VAGRANT_DEFAULT_PROVIDER export VAGRANT_DEFAULT_PROVIDER=vmware_fusion

When you pass an argument to a function, and the argument is a prvalue expression of the function's parameter type, and this type is not a reference, then the prvalue's construction can be elided. void func(std::string str) { ... } func(std::string("foo")); This says to create a tem...

If you return an lvalue expression from a function, and this lvalue: represents an automatic variable local to that function, which will be destroyed after the return the automatic variable is not a function parameter and the type of the variable is the same type as the function's return type ...

/// <summary> /// Gets a BackgroundTask by its name /// </summary> /// <param name="taskName">Name of the task to find</param> /// <returns>The found Task or null if none found</returns> public BackgroundTaskRegistration TaskByName(string taskName) ...

Lubridate provides ymd() series of functions for parsing character strings into dates. The letters y, m, and d correspond to the year, month, and day elements of a date-time. mdy("07-21-2016") # Returns Date ## [1] "2016-07-21" mdy("07-21-2016", t...

date <- now() date ## "2016-07-22 03:42:35 IST" year(date) ## 2016 minute(date) ## 42 wday(date, label = T, abbr = T) # [1] Fri # Levels: Sun < Mon < Tues < Wed < Thurs < Fri < Sat day(date) <- 31 ## "2016-07-31 03:42:35 IST" # If an ...

with_tz returns a date-time as it would appear in a different time zone. nyc_time <- now("America/New_York") nyc_time ## [1] "2016-07-22 05:49:08 EDT" # corresponding Europe/Moscow time with_tz(nyc_time, tzone = "Europe/Moscow") ## [1] "2016-07-22 12:49:...

Extension methods are useful for adding functionality to enumerations. One common use is to implement a conversion method. public enum YesNo { Yes, No, } public static class EnumExtentions { public static bool ToBool(this YesNo yn) { return yn == YesNo.Yes; ...

The interface you defined needs to be implemented in every targeted platform. For iOS this is done through the AVFoundation framework. The following implementation of the ITextToSpeech interface handles speaking a given text in English. using AVFoundation; public class TextToSpeechiOS : ITextToS...