const sucks

[Bill Baxter]

On Sat, Oct 18, 2008 at 2:22 PM, Andrei Alexandrescu
<SeeWebsiteForEmail at erdani.org> wrote:
> Dave wrote:
>>
>> "Andrei Alexandrescu" <SeeWebsiteForEmail at erdani.org> wrote in message
>> news:gd85n2$9rq$1 at digitalmars.com...
>>>
>>> Just got this from Eric Niebler:
>>>
>>> http://tinyurl.com/4apat7
>>>
>>> Guess what Anders Heljsberg and Guy Steele have to say about future of
>>> programming languages.
>>>
>>> Immutable and eliminating side effects are necessary. Quickly written
>>> down
>>> from Anders: "...we need support for immutable data at the language
>>> level..." "...so that the compiler can infer that there is isolation..."
>>> "... formalization of immutability... we don't have them in the language
>>> and it's nontrivial to put them in... and that's the big challenge." He
>>> goes on and describes the difficulties... and mentions "pure functions"
>>> and "transitivity" and "functional extensions"!!! "Pure FP is not the
>>> solution... what we try to do is to have islands of purity in functional
>>> style and switch between default to functional in a hybrid style of
>>> programming... the answer is not at the extreme..."
>>>
>>> This is huge. You have to listen to it to hear just how huge it is. He is
>>> essentially describing some of the difficulties we have encountered and
>>> already solved in D2, so it looks we have a strategic advantage.
>>>
>>> This is the confirmation I hoped was going to come someday. If it
>>> surprises me, it that it comes so early, so unequivocally, and so aligned
>>> terminologically. I'm in Nirvana.
>>>
>>
>> Anders mentioned "... be clearer about where the mutation occurs and where
>> the side-effects are, by in a sense switching the default to be more
>> functional".
>>
>> Should D3 be the version that introduces default immutable storage and
>> default pure functions?
>>
>> IIRC, this was discussed for D2 early on in the const discussion, but the
>> consensus then was that it was too big of a leap for an imperative language.
>
> I'm very glad someone finally answered about the main thrust of the
> interview. I was a tad let down by the thundering silence following my post,
> which I attributed to its rather strident tone; in my defense, I have to say
> I was in a state of euphoria caused by such a comprehensive confirmation of
> beliefs and thinking patterns I held dear for years.
>
> That aside, I do highly recommend interested people to watch the video. It
> is slow and boring at times, but some very interesting points are being
> made, particularly about the relationship between manycores and immutability
> (fortunately, that's also towards the beginning of the interview). It sure
> makes D look like it placed a winning bet two (three?) years ago when we
> started working on immutability.

I watched it yesterday.  It was pretty interesting, but also kinda
boring in the sense that it was like watching a video version of the D
Programming Language newsgroup from a year ago.  Thanks for the link.
I didn't really have anything to say other than agree with what you
posted, so I didn't post.  :-)

Probably the most fun for me was seeing what Anders and Guy are like,
since I've heard their names many times, but never their faces or
their speaking.

--bb