Re: FAQ and string functions

[Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>]

Darren New <dnew@san.rr.com> writes:

> Sure. I think the problem is that there's a host of low-efficiency
> operations in Perl that take advantage of built-in data structures. That Ada
> offers fixed strings, bounded strings, and unbounded strings indicates that
> it has a focus on efficiency that something like Perl doesn't. If Ada didn't
> have unbounded strings, people would have to keep reimplementing it. Ada
> doesn't have unbounded arrays, and people have to keep reimplementing that
> (when they need it). The assign-to-a-local-in-a-declaration doesn't really
> work well when you have long-lived arrays. 

Sounds like a good component for Grace.

> I've been working in scripting languages for the last few years, and
> I see a lack in Ada of basic simple data structures, like variable
> sized arrays, content-addressable arrays, and a few other things
> like that. I can see how someone coming from Perl could miss all
> that. Once you've written programs using built-in hashtables,
> arrays, etc, it's difficult to look at a language that doesn't use
> such things and see how to do simple things. And that it isn't built
> in means it's not going to get used everywhere it should. Even if
> you build a library for UnboundedArrays, the (pulls example out of
> left ear) MIME-parsing library isn't going to return an
> UnboundedArray compatible with the one that goes into the XML
> parser. The MIME library's output strings might be
> Ada.Strings.Unbounded, and the XML parser's input strings might be
> Ada.Strings.Unbounded, but if you want to pass the array of lines
> that's the body of the message into the array of lines that's the
> XML parser's input, you're going to need to do conversions.

Unless they all use Grace components. That's the point; Perl has a
_standard_ library for doing unbounded arrays. Ada needs one. Let's
write it!

> Yes, you *could* build all that. But from a "newbie" point of view,
> having multitasking with extensive typing and all that, but lacking
> something as simple as a variable-length array, really slows down
> learning the language, because you're constantly stumbling when
> you're trying to do *simple* stuff.

I think we need to distinguish between the "language" and the
"library". I realize languages like Perl and Java deliberately try to
confuse the two, but we don't have to buy into that.

> Of course, Ada has excellent numeric support, type support,
> multithreading, etc etc etc. It also looks like the support for
> large-scale programming is excellent, altho I haven't had a chance
> to test that out.
> 
> -- 
> Darren New 
> San Diego, CA, USA (PST). Cryptokeys on demand.
>    ** http://images.fbrtech.com/dnew/ **
> 
> They looked up at me like I was a slab of beef
>   walking into an all-you-can-eat seafood buffet.

-- 
-- Stephe