How would I extend the JavaScript language to support a new operator?

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extendjavascript
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How do I add an operator to the JavaScript language.,Extending the language semantics.,Extending the language syntax.,How would I extend the JavaScript language to support a new operator?

At some point, when something executes your code in JavaScript or any other programming language - it needs to understand that code. A part of this called lexing (or tokenizing, let's not go into subtle differences here) means breaking up code like:

function foo() {
   return 5;
}
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A class or function that specifies the type of the object instance., Define the object type by writing a function that specifies its name and properties. For example, a constructor function to create an object Foomight look like this: function Foo(bar1, bar2) { this.bar1 = bar1; this.bar2 = bar2; } , You can create any number of car objects by calls to new. For example: , Then you can rewrite the definition of Car to include an owner property that takes a Person object, as follows:

new constructor[([arguments])]
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CoffeeScript Issues Bug reports, feature proposals, and ideas for changes to the language belong here.,BigInt numbers are now supported in CoffeeScript, following the same syntax as JavaScript: 42n.,Numeric separators are now supported in CoffeeScript, following the same syntax as JavaScript: 1_234_567.,Like JavaScript and many other languages, CoffeeScript supports strings as delimited by the " or ' characters. CoffeeScript also supports string interpolation within "-quoted strings, using #{ … }. Single-quoted strings are literal. You may even use interpolation in object keys.

# Install locally
for a project:
   npm install--save - dev coffeescript

# Install globally to execute.coffee files anywhere:
   npm install--global coffeescript
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Operators are software extensions to Kubernetes that make use of custom resources to manage applications and their components. Operators follow Kubernetes principles, notably the control loop., Use Custom Resources Extend the Kubernetes API with CustomResourceDefinitions Versions in CustomResourceDefinitions , Translate a Docker Compose File to Kubernetes Resources , Extending the Kubernetes API Custom Resources Kubernetes API Aggregation Layer

kubectl get SampleDB # find configured databases

kubectl edit SampleDB / example - database # manually change some settings
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The most impactful outcome of this feature might a bit subtle: with TypeScript 3.7, users can write libraries in JSDoc annotated JavaScript and support TypeScript users.,Explore how TypeScript extends JavaScript to add more safety and tooling.,How to create and type JavaScript variables,The two biggest changes are the following:

At its core, optional chaining lets us write code where TypeScript can immediately stop running some expressions if we run into a null or undefined. The star of the show in optional chaining is the new ?. operator for optional property accesses. When we write code like

tslet x = foo?.bar.baz();
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Boolean and relational operators, Boolean and relational operators ,The expression language supports the following functionality, Relational operators

The following code introduces the SpEL API to evaluate the literal string expression 'Hello World'.

ExpressionParser parser = new SpelExpressionParser();
Expression exp = parser.parseExpression("'Hello World'");
String message = (String) exp.getValue();

As an example of method invocation, we call the 'concat' method on the string literal.

ExpressionParser parser = new SpelExpressionParser();
Expression exp = parser.parseExpression("'Hello World'.concat('!')");
String message = (String) exp.getValue();

As an example of calling a JavaBean property, the String property 'Bytes' can be called as shown below.

ExpressionParser parser = new SpelExpressionParser();

// invokes 'getBytes()'
Expression exp = parser.parseExpression("'Hello World'.bytes");

byte[] bytes = (byte[]) exp.getValue();

Public fields may also be accessed.

ExpressionParser parser = new SpelExpressionParser();

// invokes 'getBytes().length'
Expression exp = parser.parseExpression("'Hello World'.bytes.length");

int length = (Integer) exp.getValue();

The String's constructor can be called instead of using a string literal.

ExpressionParser parser = new SpelExpressionParser();
Expression exp = parser.parseExpression("new String('hello world').toUpperCase()");
String message = exp.getValue(String.class);

The more common usage of SpEL is to provide an expression string that is evaluated against a specific object instance (called the root object). There are two options here and which to choose depends on whether the object against which the expression is being evaluated will be changing with each call to evaluate the expression. In the following example we retrieve the name property from an instance of the Inventor class.

// Create and set a calendar
GregorianCalendar c = new GregorianCalendar();
c.set(1856, 7, 9);

//  The constructor arguments are name, birthday, and nationality.
Inventor tesla = new Inventor("Nikola Tesla", c.getTime(), "Serbian");

ExpressionParser parser = new SpelExpressionParser();
Expression exp = parser.parseExpression("name");
EvaluationContext context = new StandardEvaluationContext(tesla);

String name = (String) exp.getValue(context);

In the last line, the value of the string variable 'name' will be set to "Nikola Tesla". The class StandardEvaluationContext is where you can specify which object the "name" property will be evaluated against. This is the mechanism to use if the root object is unlikely to change, it can simply be set once in the evaluation context. If the root object is likely to change repeatedly, it can be supplied on each call to getValue, as this next example shows:

/ Create and set a calendar
GregorianCalendar c = new GregorianCalendar();
c.set(1856, 7, 9);

//  The constructor arguments are name, birthday, and nationality.
Inventor tesla = new Inventor("Nikola Tesla", c.getTime(), "Serbian");

ExpressionParser parser = new SpelExpressionParser();
Expression exp = parser.parseExpression("name");

String name = (String) exp.getValue(tesla);

As a final introductory example, the use of a boolean operator is shown using the Inventor object in the previous example.

Expression exp = parser.parseExpression("name == 'Nikola Tesla'");
boolean result = exp.getValue(context, Boolean.class); // evaluates to true

What does this mean in practice? Suppose assignment, using setValue(), is being used to set a List property. The type of the property is actually List<Boolean>. SpEL will recognize that the elements of the list need to be converted to Boolean before being placed in it. A simple example:

class Simple {
    public List<Boolean> booleanList = new ArrayList<Boolean>();
}

Simple simple = new Simple();

simple.booleanList.add(true);

StandardEvaluationContext simpleContext = new StandardEvaluationContext(simple);

// false is passed in here as a string.  SpEL and the conversion service will
// correctly recognize that it needs to be a Boolean and convert it
parser.parseExpression("booleanList[0]").setValue(simpleContext, "false");

// b will be false
Boolean b = simple.booleanList.get(0);
        
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