W0031 - Maps Update Function Rather Than Syntax

Warning

main(K, V, Map) ->
    maps:update(K, V, Map).
%%  ^^^^^^^^^^^^^^^^^^^^^^💡 information: Consider using map syntax rather than a function call.

Explanation

The warning message indicates that a key-value is being updated in a map using the maps:update/3 function call rather than the dedicated syntax.

Whilst this will correctly update the key-value into the map, it is not considered idiomatic, and may be less efficient than using the map update syntax directly.

If the keys are constants known at compile-time, using the map update syntax with the := operator is more efficient than multiple calls to maps:update/3, especially for small maps. This implies than using the := operator should making future additions to the code also both performant and clear.

To fix the issue, use the built-in Map#{Key := Value} syntax to insert the Key and Value into the Map:

main(K, V, Map) ->
    Map#{K := V}.

Note: Use the => operator instead, if the key may not already exist in the Map.