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The main content of this article is to explain "what is Scala overloading". Interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn what Scala overloading is.

If an identifier or select e refers to a member of several classes, the referenced context is used to infer the unique member. The method used will depend on whether e is used as a function. Let A be a collection of members referenced by e.

First assume that e appears in the application as a function, such as e (args). If there is and only one optional member in An is a (possibly polymorphic) method type whose number of elements matches the number of parameters given, the optional member is selected.

Otherwise, let Ts be the type vector obtained by typing each parameter with an undefined type. The first thing to determine is the collection of available optional members. This option is available if each type in the Ts is similar to the formal parameter type in the corresponding optional member, and if the expected type is defined and the result type of the method is compatible with it. For a polymorphic method, if the local type inference can determine the type parameters, the instantiated method is available, and then the polymorphic method is also available.

Let B be an available collection of options. If B is empty, it causes an error. Otherwise, the most specific options in B can be selected with the following definitions of "equally specific" and "more specific":

 has parameterized methods of type (Ts) U, which is as specific as other members of type S if S is available for the parameter (ps) of type Ts.

 has the type [A1 >: L1: Ln: L1: Ln: L1: Ln

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