Functional Data Structures

Writing data structures functionally

Let’s keep exploring our bank account example. Here’s one way to think about it:

account:
%{
     account_number: String, 
     account_holder: %User{},
     balance: Int, 
     transaction_log: [strings],
 }

This structure works fine in many languages, but it is not a functional data structure. There’s a hidden problem. Let’s examine a quick hypothetical ...