Error handling

Back in Chapter 2, A Look at Reactive Extensions, we learned how Reactive Extensions treats errors and exceptions. It provides a rich set of combinators to deal with exceptional cases and is straightforward to use.

Despite being a pleasure to work with, core.async doesn't ship with much support for exception handling. In fact, if we write our code with only the happy path in mind, we don't even know an error occurred!

Let's have a look at an example:

(defn get-data [] 
  (throw (Exception. "Bad things happen!"))) 
 
(defn process [] 
  (let [result (chan)] 
    ;; do some processing... 
    (go (>! result (get-data))) 
    result)) 

In the preceding snippet, we introduced two functions:

• get-data simulates a function that fetches data from the network or an in-memory cache. In this case, it simply throws an exception.
• process is a function...