Learning Functional Programming in Go

Defining a filter function 

A few lines down in our main.go file, let's define a filter function that will return cars whose Make is Honda. We use our new Where method and pass it our honda literal function:

honda := func (c Car) bool {   return c.Make == "Honda"}fmt.Println("filter cars by 'Honda':", cars.Where(honda))

Here's the output:

filter cars by 'honda': [{honda accord 3000} {honda accord es 3500}]

Cool. Next, let's create a mapping function to return the price field:

price := func (c Car) Dollars {   return c.Price}fmt.Println("Hondas prices:", cars.Where(honda).SelectDollars(price))

Here's the output:

hondas prices: [3000 3500]

Since we have already filtered by Honda, the result only contains the prices of Honda cars.

Aggregation? Sure, ...