On Wednesday, 25 February 2015 at 23:33:57 UTC, H. S. Teoh wrote:
On Wed, Feb 25, 2015 at 09:26:31PM +0000, via Digitalmars-d
wrote:
[...]
On Wednesday, 25 February 2015 at 01:12:15 UTC, Zach the
Mystic wrote:
>Principle 3: Extra function and parameter attributes are the
>tradeoff
>for great memory safety. There is no other way to support both
>encapsulation of control flow (Principle 2) and the
>separate-compilation model (indispensable to D). Function
>signatures
>pay the price for this with their expanding size. I try to
>create the
>new attributes for the rare case, as opposed to the common
>one, so
>that they don't appear very often.
IIRC H.S. Teoh suggested a change to the compilation model. I
think he
wants to expand the minimal compilation unit to a library or
executable. In that case, inference for all kinds of
attributes will
be available in many more circumstances; explicit annotation
would
only be necessary for exported symbols.
I don't remember making any such suggestion...
I'm sorry then... I've pulled this from the back of my mind, and
I'm sure something similar was actually suggested (not as a
formal proposal, mind you). Maybe it was Martin Nowak, because
he's working on DIP45 (export)? But better not to speculate, lest
more innocent people get accused of proposing things ;-)
the closest I can think
of is the idea that attribute inference should always be done,
and saved
as part of the emitted object file(s), perhaps even in
generated .di
files that contain all inferred attributes. When importing some
module,
the compiler would read the inferred attributes from the saved
information. Programmers won't even need to write any
attributes except
when they want to override the compiler's inference, but the
code will
automatically get the benefit of all inferred attributes.
Library users
would also benefit by having all inferred attributes available
in the
auto-generated .di files. This can be made to work regardless
of what
the minimal compilation unit is.
Automatic inference also frees us from the concern that
functions have
too many attributes -- if the compiler will automatically infer
most of
them for us, we can freely add all sorts of attributes without
worrying
that it will become impractically verbose to write. Saving this
info as
part of the object file also lets the compiler take advantage
of these
extra attributes even when source code isn't available, or
perform
whole-program optmizations based on them.
Yes, I fully agree with that. The one thing that's then missing
is a way to disable automatic inference (for stable interfaces);
`export` fits that mold.
