Re: Introductory Presentations, especially aimed at C++ programmers!

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

On 16-12-15 22:27 , Jeffrey R. Carter wrote:
> On 12/15/2016 01:14 PM, Niklas Holsti wrote:
>> On 16-12-15 02:00 , Jeffrey R. Carter wrote:
>>
>>> Also
>>>
>>> return Line & Get_Line;
>>>
>>> is tail recursion;
>>
>> No, the last operation called is "&", not Get_Line.
>
> In Erlang,
>
> list_length ([]) ->
>    0;
> list_length ([First | Rest]) ->
>    1 + list_length (Rest).
>
> is considered tail recursion and is required to be optimized away, so
> that's how I was using the term.

Can you give me a reference on that? I'm skeptical. According to the 
Erlang manual I found, 
http://erlang.org/doc/pdf/otp-system-documentation.pdf, section 5.6.3, 
"If the last expression of a function body is a function call, a tail 
recursive call is done", but goes on to say that this example of the 
factorial function:

    fact(N) when N>0 -> N * fact(N-1);
    fact(0) -> 1.

is "not tail-recursive, since a multiplication is done on the result of 
the recursive call to fact(N-1)".

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
       .      @       .