rhai/doc/src/language/overload.md

Function Overloading
===================

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[Functions] defined in script can be _overloaded_ by _arity_ (i.e. they are resolved purely upon the function's _name_
and _number_ of parameters, but not parameter _types_ since all parameters are the same type - [`Dynamic`]).

New definitions _overwrite_ previous definitions of the same name and number of parameters.

```rust
fn foo(x,y,z) { print("Three!!! " + x + "," + y + "," + z); }

fn foo(x)     { print("One! " + x); }

fn foo(x,y)   { print("Two! " + x + "," + y); }

fn foo()      { print("None."); }

fn foo(x)     { print("HA! NEW ONE! " + x); }   // overwrites previous definition

foo(1,2,3);     // prints "Three!!! 1,2,3"

foo(42);        // prints "HA! NEW ONE! 42"

foo(1,2);       // prints "Two!! 1,2"

foo();          // prints "None."
```