Re: XML: The good, the bad, and the ugly
Date: 20 Oct 2004 00:34:16 GMT
Message-ID: <2tlq47F217j93U2_at_uni-berlin.de>
Martha Stewart called it a Good Thing when "Marshall Spight" <mspight_at_dnai.com> wrote:
> "Christopher Browne" <cbbrowne_at_acm.org> wrote in message news:2tj2geF1vkc12U1_at_uni-berlin.de...
>> Martha Stewart called it a Good Thing when "Marshall Spight" <mspight_at_dnai.com> wrote:
>> > But, as far as data management goes, they don't do so well; "Lisp program"
>> > as schema doesn't work as well as declarative schema-- Lisp is untyped.
>> > (But not as severely as XML.) Same issue with query language; it's better
>> > to write a declarative, content-addressing query than a procedure.
>>
>> Hum? Lisp is eminently strongly typed, whether we're talking about
>> the exceedingly sophisticated type tree of Common Lisp, or the
>> sparser arrangements in Scheme.
>
> But nothing is checked until runtime, so there are no type-based
> guarantees you can make about a well-formed LISP program. This
> isn't a good idea for data management, although there is a small but
> vocal minority that appears to think it's a good idea for writing
> programs. (I happen to think it's not a good idea for writing
> programs, either.)
Oddly enough, that, too, isn't actually the case.
It is quite common for Lisp compilers to do a fair bit of type checking at compile time.
The Python compiler (which was implemented _before_ other people adopted the name for a scripting language) does a quite remarkable amount of compile-time type checking for a language where "nothing is checked until runtime" and where "there are no type-based guarantees".
To wit:
"If the compiler can prove at compile time that some portion of the program cannot be executed without a type error, then it will give a warning at compile time."
<http://www.math.sunysb.edu/~sorin/online-docs/cmucl/compiler.html#toc110>
-- (reverse (concatenate 'string "ofni.secnanifxunil" "_at_" "enworbbc")) http://www3.sympatico.ca/cbbrowne/ Signs of a Klingon Programmer - 20. "Behold, the keyboard of Kalis! The greatest Klingon code warrior that ever lived!"Received on Wed Oct 20 2004 - 02:34:16 CEST