Delegates: Difference between revisions

=={{header|Sidef}}==

<lang ruby>class NonDelegate { }

class Delegate {

method thing {

return "delegate implementation"

}

}

class Delegator (delegate = null) {

method operation {

if (delegate.respond_to(:thing)) {

return delegate.thing

}

return "default implementation"

}

}

var d = Delegator()

say "empty: #{d.operation}"

d.delegate = NonDelegate()

say "NonDelegate: #{d.operation}"

d.delegate = Delegate()

say "Delegate: #{d.operation}"</lang>

{{out}}

<pre>

empty: default implementation

NonDelegate: default implementation

Delegate: delegate implementation

</pre>