On 09/01/2016 17:35, Jonathan Gibbons wrote:
I think there are enough advantages to using a properties file that it
is worth consideration, unless there are serious technical reasons
(such as difficulty using java.util.Properties::load while
bootstrapping the system) to avoid them.
Definitely worth consideration, it's simple and cute.
I can't think of any bootstrapping issues. Only code in java.can can
execute in early startup but that's enough for handling UTF-8 and ISO
8859_1 encoded files (both charsets are specified as standard charsets).
:
It is not clear to me there is any significant benefit from avoiding
the error case where a name maps to a module of a different name. Yes,
that should be checked if and when the full module declaration is
accessed, but the error is not materially different from any of the
other errors that can occur when reading a module declaration. And
there are significant benefits from specifying that the name must be
available in the properties file, because it will help to avoid
opening and reading the module definition unnecessarily.
It will help compile-time and link-time. At run-time then all
(non-shadowed) modules must be scanned so having the module names just
makes it faster to ignore shadowed modules.
:
The question about relative paths in the file is more interesting. I
would expect that most uses of this feature would use absolute paths.
If a relative path was used, then a path relative to the directory
containing the properties file would make the most sense.
Yes, I think so too as otherwise the properties file would need to be
changed each time that the working directory changes.
Finally, I don't see the need to change the signature of
ModuleFinder.of(Path...) method, other that to change the name of the
parameter from "dirs" to "paths", such that one of the entries in the
array could be the path for a properties file, just as it might be the
path for a modular jar file as discussed in alternative proposals. In
other words, I would assume that ModuleFinder.of would provide direct
support for reading properties files as well as directories, as a
means of locating module definitions.
You're right, the API sig doesn't need to change.
-Alan
