Call by binding [was Re: [Tutor] beginning to code]

[Rhodri James]

On 25/09/17 15:26, Marko Rauhamaa wrote:
> Chris Angelico <rosuav at gmail.com>:
> 
>> On Mon, Sep 25, 2017 at 7:41 PM, Marko Rauhamaa <marko at pacujo.net> wrote:
>>> In Python, all expressions evaluate pointers.
>>
>> And that's an assertion that isn't backed by anything in the Python
>> specification. Where do you get that all Python expressions are
>> pointers?
> 
> That's not what I said. I said all expressions *evaluate to* pointers.

This may well be true in particular implementations, but it is an 
implementation detail so Chris' point still stands.  Another 
implementation could evaluate expressions to indices (as BCPL used to 
treat its globals), pieces of string or cheese, who knows?

> As for the specification, it doesn't make use of the word "pointer:"

There's a reason for that...

> The (English) expression:
> 
>     The name is bound to the object.
> 
> is just another way of saying:
> 
>     A pointer to the object is stored in the variable.

It really isn't.

-- 
Rhodri James *-* Kynesim Ltd