How can I sum the key value of a list of records?

Question

For example:

{defrecord Item [cost value]}
{def items [(Item. 20 50)
            (Item. 30 40)
            (Item. 10 70)]

How would I go about summing the cost of items? (so I'd get 60)

Answer 1

user=> (defrecord Item [cost value])
user.Item
user=> (def items [(Item. 20 50)
            (Item. 30 40)
            (Item. 10 70)])
#'user/items   
user=> (reduce + (map :cost items))
60