Question

A real F# noob question, but what is |> called and what does it do?

Answer 1

It’s called the forward pipe operator. It pipes the result of one function to another.

The Forward pipe operator is simply defined as:

let (|>) x f = f x

And has a type signature:

'a -> ('a -> 'b) -> 'b

Which resolves to: given a generic type ‘a, and a function which takes an ‘a and returns a ‘b, then return the application of the function on the input.

You can read more detail about how it works in an article here.