Learning Functional Programming in Go

Converting binary operations into operations that work on lists

Consider the following operation:

1 + 2 + 3   ⇒   [1,2,3] |> List.reduce(+)

Instead of having to write all that code where we type a number, type a +, type another number, and we can feed a list of numbers into our reduce function that applies the + operation to each item and accumulates the sum.

Here's an example of appending strings:

"a" + "b" + "c"   ⇒   ["a", "b", "c] |> List.reduce(+)

What was the neutral/identity element used in each of the preceding examples?

The preceding code is F# code. The |> symbol is just a pipe symbol, like we use in a Unix terminal. It allows us to pipe the list of integers [1,2,3] or a list strings ["a", "b", "c"]  into List.reduce(+). The greater than ...