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Functions always establish a block around the body. This block has the same name as the function name. This means you can use RETURN-FROM with this block name to return from the function and return values. You should avoid returning early whenever possible. (defun foobar (x y) (when (oddp x) ...

The search pattern can also be a regular expression. Running: grep '^[A-Z]' someFile.txt When someFile.txt contains: fred 14 m foo sam 68 m bar christina 83 f baz bob 22 m qux Sam 41 m quux Will produce the output: Sam 41 m quux since this is the only line in someFile.txt starting wi...

sp_who2 This procedure can be used to find information on current SQL server sessions. Since it is a procedure, it's often helpful to store the results into a temporary table or table variable so one can order, filter, and transform the results as needed. The below can be used for a queryable v...

To create a mixin use the @mixin directive. @mixin default-box ($color, $borderColor) { color: $color; border: 1px solid $borderColor; clear: both; display: block; margin: 5px 0; padding: 5px 10px; } You can specify a list of arguments inside a parenthesis followin...

Signals and slots are used for communication between objects. The signals and slots mechanism is a central feature of Qt and probably the part that differs most from the features provided by other frameworks. The minimal example requires a class with one signal, one slot and one connection: counte...

PropertyPossible Valuesdisplaygrid / inline-grid The CSS Grid is defined as a display property. It applies to a parent element and its immediate children only. Consider the following markup: <section class="container"> <div class="item1">item1</div> &lt...

If you want to display to your users meaningful errors instead of simple "sorry, something went wrong", Rails has a nice utility for the purpose. Open the file app/controllers/application_controller.rb and you should find something like this: class ApplicationController < ActionContro...

It is possible to limit the tests executed by manage.py test by specifying which modules should be discovered by the test runner: # Run only tests for the app names "app1" $ python manage.py test app1 # If you split the tests file into a module with several tests files for an app $ p...

/** * The buildscript {} block is where you configure the repositories and * dependencies for Gradle itself--meaning, you should not include dependencies * for your modules here. For example, this block includes the Android plugin for * Gradle as a dependency because it provides the addition...

/** * The first line in the build configuration applies the Android plugin for * Gradle to this build and makes the android {} block available to specify * Android-specific build options. */ apply plugin: 'com.android.application' /** * The android {} block is where you configure all...

You can define the signing configuration to sign the apk in the build.gradle file using these properties: storeFile : the keystore file storePassword: the keystore password keyAlias: a key alias name keyPassword: A key alias password In many case you may need to avoid this kind of info in ...

In Python you can compare a single element using two binary operators--one on either side: if 3.14 < x < 3.142: print("x is near pi") In many (most?) programming languages, this would be evaluated in a way contrary to regular math: (3.14 < x) < 3.142, but in Python it ...

DROP INDEX ix_cars_employee_id ON Cars; We can use command DROP to delete our index. In this example we will DROP the index called ix_cars_employee_id on the table Cars. This deletes the index entirely, and if the index is clustered, will remove any clustering. It cannot be rebuilt without rec...

Factories can be used in conjunction with Inversion of Control (IoC) libraries too. The typical use case for such a factory is when we want to create an object based on parameters that are not known until run-time (such as the current User). In these cases it can be sometimes be difficult (if no...

If your project depends on the external libraries, you should first install them with opam. Assuming your dependencies are foo and bar and the main entry point of your project is foobar.ml you can then build a bytecode executable with ocamlbuild -use-ocamlfind -pkgs 'foo,bar' foobar.byte Warnin...

If your project has no external dependency and has foo.ml as its main entry point, you can compile a bytecode version with ocamlbuild foo.byte To get a native executable, run ocamlbuild foo.native

You can find the installers on Node.js download page. Normally, Node.js recommends two versions of Node, the LTS version (long term support) and the current version (latest release). If you are new to Node, just go for the LTS and then click the Macintosh Installer button to download the package. I...

An external procedure is one which is defined outside another program unit, or by a means other than Fortran. The function contained in a file like integer function f() implicit none end function f is an external function. For external procedures, their existence may be declared by using a...

Rendering text consumes a lot of CPU. Fonts are rendered in a fashion similar to vector graphics and contain many vector points for every character. Altering text frame-by-frame will degrade performance. The "Cache as bitmap" flag is extremely useful if used correctly, meaning you must avo...

Using ActiveCell or ActiveSheet can be source of mistakes if (for any reason) the code is executed in the wrong place. ActiveCell.Value = "Hello" 'will place "Hello" in the cell that is currently selected Cells(1, 1).Value = "Hello" 'will always place "Hello&...