Re: why not

["Marin David Condic" <dont.bother.mcondic.auntie.spam@[acm.org>]

The idea here is that there are a bunch of available container libraries
that will provide - with varying levels of detail - things like lists, maps,
trees, etc. and why not lets all settle on using just one of them so it
becomes a kind of "convention" and makes it easier to use code written by
others, easier to teach Ada to newbies, provides extra facilities within the
language, etc. Sort of like C++ adopting STL and making it part of the
language, Ada could work towards something similar and thus (eventually)
arrive at a richer language.

Why would it need to come with a compiler? It doesn't really - there are a
bunch of them you can download right now that will be usable in a number of
environments. (Will they compile on all Ada compilers? Depends on how well
built they are and if the compiler in question maybe has bugs, right? You
can *always* make a given program dependent on things that are available in
only one implementation.) You can (and should) write a container library as
a compiler independent thing and I suspect most of the ones you'll encounter
will compile/run with most compilers. Until you get there and do it though,
you don't really know that this is true.

The reason for having it come with the compiler is to encourage users to use
one, common package. In Ada83, people developed their own string handling
utilities. In Ada95, there were some nice packages provided under
Ada.Strings... and new developments almost certainly use these packages
rather than various home grown answers. When you look at that code, you
pretty much know what is going on because you are already familiar with
Ada.Strings.<whatever>. You also continue to leverage Ada.Strings.<whatever>
and speed your development time by using a common package that everyone
knows about. If a collection of data-structurey-stuff was available to you
just by virtue of coming along with the compiler, chances are you'd leverage
it the same way. (In the standard or not - if it comes along with
some/most/all compilers, you'll probably want to use it rather than building
one of your own.)

How does a component library get some kind of widespread adoption? That's
obviously an open topic for discussion here! :-) Getting some general
agreement on what it should look like is a good place to start though.

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com
Web:      http://www.mcondic.com/


"Darren New" <dnew@san.rr.com> wrote in message
news:3BE1A1D5.A1DC08AE@san.rr.com...
>
> What I'm not clear on, being an Ada newbie, is why it needs anything
> more than this. That is, shouldn't something like a data type library be
> exceedingly portable? Shouldn't one be able to write something like a
> red-black tree in pure Ada without relying on anything
> compiler-specific? I'm not sure why GNAT's regexp, for example, needs
> the GNAT compiler. I haven't looked into it at all, but I can't imagine
> what could possibly be in there, given that it's basically manipulation
> of arrays of characters, yes?
>
> So what am I missing? Why would a doubly-linked list need to come with a
> compiler?
>