Pipe Operator in

About Pipe Operator

The |> operator is called the pipe operator. It can be used to chain function calls together in such a way that the value returned by the previous function call is passed to the next function call.

"hello"
|> string.uppercase
|> string.append("?!")
// -> "HELLO?!"

The above code is equivalent to the following:

string.append(string.uppercase("hello"), "?!")

The pipe operator will either pass the value as the first argument to the function call, or the only argument to a new call, selecting whichever would have the correct type.

100
|> function_that_takes_two_arguments(1)

// Is equivalent to
function_that_takes_two_arguments(100, 1)

100
|> function_that_returns_a_function(1)

// Is equivalent to
function_that_returns_a_function(1)(100)

Sometimes we want to pass the value into another position, in this case the _ placeholder can be used to indicate where the value should be inserted.

100
|> some_function(1, _, 2)