> So what is the difference between "registering files" and "importing
> subsystems/views" from an Ada source code perspective? Very little it
> seems. I haven't used Apex, but how does it handle multi-compilation unit
> Does it have the same restrictions as GNAT (i.e. one compilation unit per
> If this is true, then I would guess that the Apex mechanism is not that
> different to the ada-mode mechanisms for Projects using Emacs and GNAT.
> John

Importing subsystems/views is closer to having a default set of -I lines
to gnatmake (include path) on a per directory basis (this is a
simplification of
the power of subsystems/views but it is the best analogy).
Apex requires one compilation unit per file and also requires that files
follow a
specific naming convention. The big difference between the models is that
Apex holds onto
ASIS and/or other tree data after the compile so that it can be used later
by other
tools (or during other compiles).  This lets them avoid having to re-parse
all the with'd
specs of a file. As to whether or not this is faster than the GNAT
model......Not even close up
to version 3.0.0b (I have heard that the 3.2 series is faster).