operator == method

Test whether another object is equal to this function.

System-created function objects are only equal to other functions.

Two function objects are known to represent the same function if

• It is the same object. Static and top-level functions are compile time constants when used as values, so referring to the same function twice always give the same object,
• or if they refer to the same member method extracted from the same object. Extracting a member method as a function value twice gives equal, but not necessarily identical, function values.

Function expressions never give rise to equal function objects. Each time a function expression is evaluated, it creates a new closure value that is not known to be equal to other closures created by the same expression.

Classes implementing Function by having a call method should have their own operator== and hashCode depending on the object.