🚀 go-pugleaf

In article <BxAq2J.4Kv@cs.uiuc.edu> johnson@cs.uiuc.edu (Ralph Johnson)  
writes:
> [...]
> There are at least two levels of meaning to an interface like "American
> house current".  One is the meaning known to an EE.  The other is the
> meaning known to my mother.  My mother doesn't know anything about volts
> or frequency.   She just knows that she can connect a plug into a
> compatible socket.  EVERYBODY in the country knows what "you have to  
plug
> an applicance in before it will work", that was my point.  You don't
> have to know ANYTHING about the details of the interface to use it.
> 
Your mother do not know that she will get electricity when connecting a  
plug into a compatible socket? I cannot believe that. I am sure she uses  
this important property when combing plugs and sockets.
> What this means in a software system is that we shouldn't have to know
> anything about the details of an interface except its name.  We should
> only have to know that we need a FOO, not what operations are legal on
> a FOO.
You relly need more details of an interfact than only its name. The  
properties of an interface are the most important issue whereas the  
concrete names do not play any formal role. It is not important if i call  
a function called OpenWindow or a function called CupOfTea. It is only  
important what happens when calling the function!
> 
> 
> Ralph Johnson -- University of Illinois at Urbana-Champaign