From: Matthew Moss <matt@...>
Date: 2008-12-13T04:39:38+09:00
Subject: Re: parallel method return value


On Dec 12, 2008, at 1:25 PM, Louis-Philippe wrote:

> Hi guys,
>
> Thanks for your answer,I get your points...
> but in this case, what I really want to do is have the method return  
> the
> right number of values for the corresponding quantity of lvalues  
> presented
> to it, to make it context sensitive you know, so I can have, for  
> example, a
> boolean first return value when it is called with one lvalue and a  
> boolean
> plus a string when called with two rvalue.  The assignment operator  
> does it,
> so I would have expected the same behaviour to also work with a  
> method.

But as was pointed out, methods _always_ return one value, even if it  
appears to return multiple values. They are lumped together into one  
array.

> right now my options are:
>
> a, = a_method
>
> or
>
> a = a_method[0]
>
> both ways still involve to ask for only one to return.  What I am  
> looking
> for, if it exist, is for the method to automatically detect context  
> and act
> from it like the = operator.  I find how the assignment operator  
> implements
> this is very elegant, and am crave it for methods!!

There isn't any way for the method call to recognize the context in  
which it is being called. You'd have to pass an argument, such as the  
"number of return values" to return.

     a, b = a_method(2)
     a = a_method(1)

Which seems pointless, when you can instead do what you've already  
identified as the proper technique:

     a, = a_method
     a, b = a_method
     a, b, c = a_method
     # etc.

> Anybody can prove this wrong?  (please!!)

No, because what was provided before wasn't wrong.