W0030 - Maps Put Function Rather Than Syntax

Warning

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

Explanation

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

Whilst this will correctly and unconditionally insert 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:put/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, for performance and code clarity, if the key should already exist in the Map.