Re: call/cc discussion

[David Kastrup <dak@...>]

Javier Guerra Giraldez <javier@guerrag.com> writes:

> On Thursday 23 August 2007, Thomas Breuel wrote:
>
>> I hope people aren't seriously considering adding call/cc to
>> Lua... call/cc is a nice didactic feature in Scheme, but for a
>> real-world scripting language, there are other constraints on
>> language design.
>
> care to elaborate?
>
> i'd really like some 'advantages' of not having full continuations;
> that way i wouldn't feel them as "almost the last piece missing to
> feel superior to Schemers"

Take a cold shower.

Lua is designed according to the Mies van der Rohe principle: "a
design is not perfect when you can't add anything to it, but when you
can't take anything away from it."

That's one of its chief selling points, and so all "embrace and
extend" leanings need to be kept in check.

"Somebody else has this" can't be a criteria for Lua: would you, for
example, want to have all the obfuscate nonsense that is possible in
C++ and which sane programmers will use only in very constrained and
controlled manners if at all?

That does not mean that a beautiful and straightforward useful
implementation would have no chance of acception: Lua's coroutines
fall in that class.  They have not been around from the start, but
they fit the language perfectly well.

But one should not start with the "we must have this at any cost"
attitude: that way, the cost will likely be too high.

-- 
David Kastrup