Merge

Today was tightening up a lot of loose ends before IPM tomorrow. I did learn of a very useful function for dealing with maps today merge.

What does Merge Do?

The merge function in Clojure takes multiple maps as arguments and returns a new map that combines all of them. If the same key exists in more than one map, the value from the last map passed to merge will overwrite the previous ones. This behavior makes merge handy for combining configuration settings, user inputs, or any other scenarios where maps need to be unified.

Here’s a simple example:

(def map1 {:a 1 :b 2})
(def map2 {:b 3 :c 4})

(merge map1 map2)
;; => {:a 1, :b 3, :c 4}

In this example, the key :b appears in both map1 and map2. The value from map2 (3) overwrites the value from map1 (2), resulting in the final merged map {:a 1, :b 3, :c 4}.

When merging maps, conflicts are resolved by taking the value from the last map provided.