DeRailed DSL (was Re: compile-time regex redux)

[kris]

Andrei Alexandrescu (See Website For Email) wrote:
> kris wrote:
> 
>> Andrei Alexandrescu (See Website For Email) wrote:
>>
>>>>> I think there is a lot of apprehension and misunderstanding 
>>>>> surrounding what metacode is able and supposed to do or simplify. 
>>>>> Please, let's focus on understanding _before_ forming an opinion.
>>>>
>>>>
>>>>
>>>> If that's the case, then perhaps it's due to a lack of solid & 
>>>> practical examples for people to examine? There's been at least two 
>>>> requests recently for an example of how this could help DeRailed in 
>>>> a truly practical sense, yet both of those requests appear to have 
>>>> been ignored thus far.
>>>>
>>>> I suspect that such practical examples would help everyone 
>>>> understand since, as you suggest, there appears to be "differences" 
>>>> in perspective? Since Walter brough RoR up, and you apparently 
>>>> endorsed his point, perhaps one of you might enlighten us via those 
>>>> relevant examples?
>>>>
>>>> There's a request in the original post on "The DeRailed Challenge" 
>>>> for just such an example ... don't feel overtly obliged; but it 
>>>> might do something to offset the misunderstanding you believe is 
>>>> prevalent.
>>>
>>>
>>>
>>> I saw the request. My problem is that I don't know much about 
>>> DeRailed, and that I don't have time to invest in it. 
>>
>>
>> You wrote (in the past):
>> ====
>> I think things would be better if we had better libraries and some 
>> success stories.
>> ====
>>
>> We have better libraries now. And we're /trying/ to build a particular 
>> success story. Is that not enough reason to illustrate some practical 
>> examples, busy though you are? I mean, /we're/ putting in a lot of 
>> effort, regardless of how busy our personal lives may be. All we're 
>> asking for are some practical and relevant examples as to why advanced 
>> DSL support in D will assist us so much.
>>
>>
>>> My current understanding is that DeRailed's approach is basically 
>>> dynamic, a domain that metaprogramming can help somewhat, but not a 
>>> lot. The simplest example is to define variant types (probably they 
>>> are already there) using templates. Also possibly there are some code 
>>> generation aspects (e.g. for various platforms), which I understand 
>>> RoR does a lot, that could be solved using metacode.
>>
>>
>> I read "Possibly there ... Could be solved ..."
>>
>> Forgive me, Andrei, but that really does not assist in comprehending 
>> what it is that you say we fail to understand. Surely you would agree? 
>> Variant types can easily be handled by templates today, but without an 
>> example it's hard to tell if that's what you were referring to.
>>
>> On Feb 7th, you wrote (in reference to the DSL discourse):
>> =====
>> Walter gave another good case study: Ruby on Rails. The success of Ruby
>> on Rails has a lot to do with its ability to express abstractions that
>> were a complete mess to deal with in concreteland.
>> ====
>>
>> On Feb 7th, Walter wrote (emphasis added):
>> =====
>> Good question. The simple answer is look what Ruby on Rails did for 
>> Ruby. Ruby's a good language, but the killer app for it was RoR. RoR 
>> is what drove adoption of Ruby through the roof. /Enabling ways for 
>> sophisticated DSLs to interoperate with D will enable such applications/
>> =====
>>
>> You see that subtle but important reference to RoR and DSL in the 
>> above? What we're asking for is that one of you explain just exactly 
>> what is /meant/ by that. DeRailed faces many of the same issues RoR 
>> did, so some relevant examples pertaining to the RoR claim may well 
>> assist DeRailed.
>>
>> Do we have to get down on our knees and beg?
> 
> 
> Aw, give me a break.
> 
> Andrei


Hrm ...

Perhaps it should be pointed out that some of us are going to great 
personal expense and effort to further D in the marketplace. Because of 
that, what you read above is both a sincere and honest effort to elicit 
concrete assistance based upon relevant claims made (above).

Your response is not quite as helpful as it might be; but then it would 
appear to have been intended for other effect? What we really need is 
some assistance instead.

Thank you;

- Kris