Fawzi Mohamed wrote:
On 12-mar-10, at 09:59, Don wrote:
BCS wrote:
Hello Walter,
2. If a loop is detected, rather than issuing an error message, simply
arbitrarily pick one order and continue constructing.
How about a way to explicitly cut edges in the graph (tagging imports
with "pragma(nodep)" or "@nodep" for instance)? That has the same end
effect but for only a little more work, removes any non-determinism
and allows for easy control of how things are resolved.
I agree. Seems to me that if a circular import exists, it's really
something that the programmer needs to think about, and so it's
reasonable for it to be explicit.
A really harsh solution would be:
pragma(nodependency, somepackage.somemodule);
The compiler could check that somepackage.somemodule actually defines
a static constructor. And it could even check that a circular import
situation actually exists. This would force the pragma to be
maintained correctly.
I think that the main problem comes from static initializers that are
mixed in and by themselves have no circular dependency.
If that's true, then perhaps a more restricted solution is better.
Eg, use Walter's proposal ONLY if the static initializer is mixed in.
