In 1.12, use arity for method selection disambiguation where possible

Question

Where possible, it would be nice to use arity to guide the method overload disambiguation, to reduce the need for hinting. For example:

(map ^[int] Integer/toString [0 1 2 3])

Here the compiler requires the hint due to the lack of type inference. However:

(^[] String/toLowerCase "Foo")

It seems like this case should be able to be disambiguated without the hint, based on the arity.

Answer 1

This is by design - in qualified constructor, instance method, and static method symbols in invocation or value position require you to specify exactly one method arity/overload via if param-tags. No inference is done, no reflection occurs, and you wll get a compiler exception if the method is ambiguous.

The one special case is static methods in invocation position, as this was the only pre-existing place where qualified methods were allowed, and inference was previously used. For backwards compatibility, inference will still be used in this case (if no param-tags are provided).