Groovy supports operator overloading since the start. Operator overloading is implemented by an actual method signature that maps to an operator. For example an object with a plus method can be used with the + operator. There is a list of methods and operators available on the Groovy website.
As long as an object has a method with a name that Groovy understands the corresponding operator can be used in Groovy code. This is even true for Java objects. Since Groovy 5 you can use the groovy.transform.OperatorRename annotation on classes, methods or constructors to map other method names to the Groovy operator overloading method names. This is very useful for third-party classes that you cannot change, but still want to use simple operators in Groovy code. You can reassign a method name to the following methods so an operator can be used: plus, minus, multiply, div, remainder, power, leftShift, rightShift, rightShiftUnassigned, and, or, xor, compareTo. Suppose you use a class with an add method and want to use the + operator for this method. The following annotation can be used @OperatorRename(plus = 'add') for a method and inside the method you can use the + operator instead of the add method of the class.

Since Groovy 1.8.3 Groovy has an implies() method for Boolean types. Groovy 5 adds an operator ==> for this method so you have a shorter way to express a logical implication. A logical implication is a logical function that can be expressed as P ==> Q. You can read this as P implies Q or if P than Q. This expression is true in every case except when P is true, but Q is false. The following truth table shows the interpretaton of the logical implication operator:

Groovy 5 adds support for using an index variable in a for-in loop. You must define an extra variable as first argument of the for loop. This variable will be used as index variable. For each iteration of the code in the for-in loop the value of this index variable is incremented by 1. You can use this value in the for loop.

Groovy 5 adds a new utility method to create an ascii bar chart. You can use the bar method in the org.codehaus.groovy.util.StringUtil class. You can pass a value, a minimum and maximum value and optinally specify the width of the bar chart. The result is a String value consisting of a number of "blocks". A block could be whole, but also 1/8 eights of the block are used to get a nice looking bar chart. How many of these values are needed is based on the input arguments. With this method you have a nice way to format number values on a command-line.

Groovy is known for exending standard Java classes with extra methods or extra arguments for existing methods. Since Groovy 5 you can use a range as argument for the List.subList method. The range is used to determine the begin and end index of the original List instance to return.

Groovy 5 introduced some extra overloaded methods for the collectEntries method, that can be used to transform an iterable object into a Map. You can now pass a closure or function as arguments to transform the original iterable element into the key and value for the resulting Map. It is now also possible to pass a so-called collector Map that will be used to extend with new key/value pairs.

Besides extra overloaded method signatures for collectEntries Groovy 5 also adds the new methods withCollectedKeys and withCollectedValues. With the method withCollectedKeys a closure or function can passed to create the keys for the new Map based on the elements from the iterable. The value of the key/value pair is the unchanged element. You use the method withCollectedValues to pass a closure or function to create the value for the new key/value pair in the resulting Map. The key will be the original element from the iterable.

The Nushell command enumerate adds an index value to each item in a list. The index value is stored in an extra column named index. You can use this column to filter data based on the index value.

Nushell has very useful commands to filter lists and tables. When you have a list with null values, you can use the compact command to filter out the null values. With the option --empty you can also filter out empty items like empty strings, empty lists and empty records. If you want to filter out rows in a table where a column contains a null value, you can use the compact command followed by the name of the column.

Nushell has some nice built-in commands to get randomized data. The random command can be used to get random numbers, strings, and more. You can use the dice subcommand to get random numbers between 1 and 6. The command returns a list of integers. With the option --dice you can specify how many times to throw the dice. By default the dice has 6 sides, but you can use the option --sides to change that. You could roll a dice with 2 sides, like flipping a coin, or roll a dice with 10 sides.

The nice thing about the http command in Nushell is that you can interact with HTTP endpoints without the need to install any external tools. You can use several subcommands like get, post, put, delete and patch. Each of these commands has the options to specify request headers. You can use the option --headers or the short version -H followed by a list of header keys and values.

The http command in Nushell can be used to interact with HTTP endpoints. You can post data to an endpoint using the post subcommand. If you want to post JSON data than you can simply use a record data structure and use the argument --content-type application/json (or the shorthand -t application/json). Nushell will automatically convert the record data structure to JSON and use it as the body of the HTTP request.

Nushell has a built-in command to invoke HTTP requests: http. You don’t need an external tool like curl or httpie to make HTTP requests. There a lot of options to use with the http command. One of them is the --full or shorter -f option to return a table with extra details of the HTTP request and response. The request and response headers, the body and status are returned in the table. You can easily get information from the table with all the default selection options for a table structure.