> > So what is the difference between "registering files" and "importing > subsystems/views" from an Ada source code perspective? Very little it would > seems. I haven't used Apex, but how does it handle multi-compilation unit files? > Does it have the same restrictions as GNAT (i.e. one compilation unit per file)? > > 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).