Call an object method: Difference between revisions

=={{header|Factor}}==

In Factor, there is no distinction between instance and static methods. Methods are contained in generic words and specialize on a class. Generic words define a <i>method combination</i> so methods know which object(s) to dispatch on. (But most methods dispatch on the object at the top of the data stack.) Under this object model, calling a method is no different than calling any other word.

<lang factor>! Define some classes.

SINGLETON: dog

SINGLETON: cat

! Define a generic word that dispatches on the object at the top

! of the data stack.

GENERIC: speak ( obj -- )

! Define methods in speak which specialize on various classes.

M: dog speak drop "Woof!" print ;

M: cat speak drop "Meow!" print ;

M: object speak drop "I don't know how to speak!" print ;

! Place three objects of different classes on the data stack.

dog cat 10

! Call speak, a method, just like any other word.

[ speak ] tri@</lang>

{{out}}

<pre>

Woof!

Meow!

I don't know how to speak!

</pre>