We can create our custom operators and combine them. It is not a common practice but can be useful in some cases.

Let’s start by creating an operator similar to the UNIX pipeline |:

echo “Hello” | wc -l

This operator will redirect the output from the left, as an input for the right closure:

precedencegroup ForwardApplication {
    associativity: left
}

infix operator |: ForwardApplication

func |<A, B>(_ x: A, f: (A) -> B) -> B {
    f(x)
}

3 | String.init //"3"
String(3) //"3"

Usually we will use String(3), but we can use | to forward the left value as an input for the right function.

We can indicate with precedence group how to evaluate in cases where we have multiple operators.

3 | String.init | someOtherFunctionWithSameInputOutput