Re: Looking for volunteers for XL

"Kaz Kylheku" <kaz@kylheku.com> wrote in message
> On 2011-11-26, BartC <bc@freeuk.com> wrote:


>> However, if the design of X2 isn't going to change, you might as well
>> just write a compiler directly for X2; it's not necessary to make
>> available, to the programmer of X2, all those untidy language-building
>> features (for an example, see C++).


> You're trying to fit extensible languages into the traditional model,
> in which a lone guru (or small group of such) working atop a mountain
> carves a programming language onto stone tablets, which then descend
> down to the masses.


You've put that well, that's exactly what I think!


Take the well-known language C, which has a crude mechanism to extend
it in the form of its pre-processing macro language.


Most enhancements you might want to make to the language, can be
achieved by some clunky, ugly macro. But the real problem is that your
code now consists of a private, ad-hoc collection of macros which
no-one else understands. You can't upload a simple piece of code (for
example a problem-solving algorithm) without dragging this macro
library with it.


And even then, someone else has to integrate this code with his own,
where the same language issue has been solved in a slightly different
way, or in a way that clashes.


Wouldn't it be much better standardising these enhancements so everyone
writes them the same way?


(Of course macros can work well for application-related tasks; I'm talking
about language enhancements.)


> Under an extensible language culture, the lone guru working in
> isolation produces not a new language, but some new extension. These
> can be released as code for people to try. Then when the bug reports
> pour in and it's all hammered out, a formal spec can be written. The
> guru deosn't get to ask everyone to ditch their language, only to add
> something to it.


That's fine. There's just one guru; only he needs the tools to create the
extensions. The problem is when everyone can potentially be a guru because
every has the tools (and a much bigger, more confusing toolbox with lots of
intriguing-looking tools for the programmer to express himself with!).


--
Bartc
[Anyone ever look at the code for the Bourne shell, written in faux
Algol-68 using C preprocessor macros. Yow. -John]

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