Talk:Respond to an unknown method call: Difference between revisions

:: There are three ways to send a message to an object in PicoLisp: (message1> Obj), (send 'message1> Obj) and (try 'message1> Obj). The standard way, (message1> Obj), is just a convenient abbreviation of (send 'message1> Obj). They all three do a dynamic search for a definition of 'message1>' in Obj and its (super)classes. If a method definition is found, it is executed in the context (i.e. 'This') of Obj. If no such method is found, the case must be handled explicitly (what else?). And that's what 'try' is for, because the direct call and the one with 'send' throw an error.

:: So 'try' is the "primitive" form of 'send', which allows you to roll your own special method invocation, like calling (try 'unknown> Obj), and handling it yourself. Then calling some other function or method is the only way for the object to "respond (sensibly/usefully)". Not that an object can never "respond" all by itself, there must always be some function call involved (explictly or implicitly). --[[User:Abu|Abu]] 00:55, 7 Nov 2011 (UTC)