Basic usage

Matching Literals

The simplest thing you can do is match literals:

(let [x true
      y true
      z true]
  (match [x y z]
    [_ false true] 1
    [false true _ ] 2
    [_ _ false] 3
    [_ _ true] 4
    :else 5))

Note that the only clause that matches the values of the local variables is the fourth one.

When matching on a single variable you may omit the brackets:

(let [x true]
  (match x
    true 1
    false 2
    :else 5))

Binding

You may match values and give them names for later use:

(let [x 1 y 2]
  (match [x y]
    [1 b] b
    [a 2] a
   :else nil))

This may seem pointless here but in complex patterns this feature becomes more useful (consider red black tree balancing for example).

Sequential types