WAS Re: [Caml-list] Re: The need to specify 'rec' in a recursive function defintion

WAS Re: [Caml-list] Re: The need to specify 'rec' in a recursive function defintion

[Grant Rettke]

On Tue, Feb 16, 2010 at 10:21 AM, Ashish Agarwal <agarwal1975@gmail.com> wrote:
> let rec

Do OCaml'er look at let rec more as being a message to the programmer,
rather than the compiler, that the way I want to define this function
is recursively so even if 'f' was previously bound you know which one
I mean?

Considering the language allows mutation, I feel like it is more for
humans than the compiler, but of course, the compiler must be told,
too.

Re: WAS Re: [Caml-list] Re: The need to specify 'rec' in a recursive function defintion

[Jon Harrop]

On Tuesday 16 February 2010 16:47:03 Grant Rettke wrote:
> On Tue, Feb 16, 2010 at 10:21 AM, Ashish Agarwal <agarwal1975@gmail.com> 
wrote:
> > let rec
>
> Do OCaml'er look at let rec more as being a message to the programmer,
> rather than the compiler, that the way I want to define this function
> is recursively so even if 'f' was previously bound you know which one
> I mean?

I see it as resolving an ambiguity for both the programmer and compiler. There 
are alternatives as others have mentioned but none seem particularly good or 
bad to me. Moreover, the burden of "rec" is tiny so I don't think it is worth 
discussing in such detail.

-- 
Dr Jon Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/?e

Re: WAS Re: [Caml-list] Re: The need to specify 'rec' in a recursive function defintion

[Andrej Bauer]

>Moreover, the burden of "rec" is tiny so I don't think it is worth
>discussing in such detail.

Ah, but you are forgetting Wadler's Law.

Re: WAS Re: [Caml-list] Re: The need to specify 'rec' in a recursive function defintion

[Grant Rettke]

On Tue, Feb 16, 2010 at 1:08 PM, Jon Harrop <jon@ffconsultancy.com> wrote:
> On Tuesday 16 February 2010 16:47:03 Grant Rettke wrote:
>> On Tue, Feb 16, 2010 at 10:21 AM, Ashish Agarwal <agarwal1975@gmail.com>
> wrote:
>> > let rec
>>
>> Do OCaml'er look at let rec more as being a message to the programmer,
>> rather than the compiler, that the way I want to define this function
>> is recursively so even if 'f' was previously bound you know which one
>> I mean?
>
> I see it as resolving an ambiguity for both the programmer and compiler. There
> are alternatives as others have mentioned but none seem particularly good or
> bad to me. Moreover, the burden of "rec" is tiny so I don't think it is worth
> discussing in such detail.

It wasn't about the "burden" of having to type 4 extra characters;
rather I was trying to understand the philosophy behind the langguage.

Re: WAS Re: [Caml-list] Re: The need to specify 'rec' in a recursive function defintion

[Grant Rettke]

On Wed, Feb 17, 2010 at 12:09 PM, Andrej Bauer <andrej.bauer@andrej.com> wrote:
>>Moreover, the burden of "rec" is tiny so I don't think it is worth
>>discussing in such detail.
>
> Ah, but you are forgetting Wadler's Law.

You mean this:

" Wadler's Law:
       The emotional intensity of debate on a language feature
       increases as one moves down the following scale:
           Semantics,
           Syntax,
           Lexical syntax,
           Comments."?