[Tutor] Function Return Values (or References)

[John Steedman]

Thanks for all these clear and knowledgeable answers.  I'm much clearer on
this now and will read up a bit more around these subjects.

John


On Mon, Jun 24, 2013 at 10:59 AM, Peter Otten <__peter__ at web.de> wrote:

> John Steedman wrote:
>
> > Hi Tutors,
> >
> > I'm confused by the following possible contradiction. Would someone
> please
> > explain or point me to the right docs.
> >
> > FACT 1
> >
> > "Variables in python hold references to objects."
> > http://en.wikipedia.org/wiki/Python_syntax_and_semantics
> >
> > FACT 2
> >
> >>>>def Increment ( x ) :
> >>>>    // return x + 1
> >>>>    x = x + 1
> >>>>    return x
> >>>>
> >>>>y = 1
> >>>>z = Increment ( y )
> >>>>y
> > 1
> >>>>z
> > 2
> >
> > By FACT 1  x should be a reference parameter...?
> > By Fact 2 x would seem to be a copy...?
> >
> > What in the world of dynamic typing is going on?
>
> There's a big confusion in terminology. Does
>
> http://en.wikipedia.org/wiki/Evaluation_strategy#Call_by_sharing
>
> help? Here's a more detailed explanation:
>
> <
> http://learntofish.wordpress.com/2012/01/09/call-by-object-reference-call-by-sharing/
> >
>
>
>
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