Re: ocaml: demand-driven compilation?

[Ian T Zimmerman <itz@rahul.net>]

In message <6086.199709131752@venus> (message from William Chesters on Sat,
	13 Sep 1997 18:52:43 +0100),
you <williamc@dai.ed.ac.uk> write:
>  Are there plans to extend the separate compilation system of ocaml
> to take over some of the functions of make, as the Java compiler
> does?  The Java compiler not only checks sources against the
> precompiled signatures of the modules it refers to, as
> ocamlc/ocamlopt do; it also checks the existence and modtime of the
> bytecode file against the source and (re)compiles if necessary.
> With a little hack to get any necessary standard libraries included
> in the link command automagically, we wouldn't need makefiles at
> all.  For me it would even be nice to able to specify the C files
> implementing the external functions needed by each source _in the
> source itself_.

IMO things like this don't belong to the language or compiler.  It is
a _disadvantage_ of Java that it tries to be a `complete environment',
and I bet the reasons why it is packaged that way has a lot to do with
marketing b*s*t.  Apart from the general reasons of going against the
toolkit philosophy (if you try to have a program do too much, it stops
cooperating nicely with the rest of the system), in a compiler there's
another reason: depending on the file system in nontrivial ways would
make it harder or impossible to verify that the language has a sound
semantics and that the compiler implements the semantics correctly.

>  It would also be possible to do it (approximately) without touching
> the compiler, say using ocamldep, but it would get messy.

Yes, it would definitely be possible to beef up ocamldep.  The result
would be a reimplementation of make in ocaml.  Why reinvent the wheel?
And why do you dislike makefiles anyways?  They are the right tool for
the job.

Just my penny worth.

-- 
Ian T Zimmerman                        <itz@rahul.net>
The dilemma is that when you model something 
completely on efficiency, a lot of people get hurt.
Dr. Leonard Duhl of UC Berkeley, discussing `managed medical care'.