Fixing cyclic import static construction problems

[Jonathan M Davis]

On Thursday, November 29, 2012 12:39:19 Paulo Pinto wrote:
> On Thursday, 29 November 2012 at 03:19:55 UTC, Andrei
> 
> Alexandrescu wrote:
> > On 11/28/12 9:34 PM, Walter Bright wrote:
> >> For discussion:
> > [snip]
> > 
> > I'd say we better finish const, immutable, and shared first.
> > 
> > Andrei
> 
> +1
> 
> Fully agree.
> 
> Cyclic imports are a minor nuisance that can be easily solvable
> with better code architecture.
> 
> Turbo Pascal/Delphi is the only language that I know fully allows
> cyclic dependencies between modules. So this is not that
> important for most people.

Basic features in the language require static constructors (e.g. static 
variables frequently do), and some things just can't be done without them. 
Andrei's std.benchmark proposal actually doesn't work, because in order to do 
what it does, in needs to mixin in a static constructor and static destructor 
(to set up the benchmarking and record it at the end, I believe). That 
completely falls apart due to cyclical imports. It doesn't actually cause any 
true circular dependencies, but it's treated as such anyway. A _lot_ of us 
have run into this problem and a number of us consider it to be a huge design 
problem in the language. Personally, I'd put it towards the top of design 
mistakes at this point, and I'm very glad to see Walter actually finally being 
willing to do something about this. In the past when I've brought up similar 
solutions, he's been completely opposed to them.

Yes, we have other major issues that need to be resolved, and those may very 
well be of a higher priority, but this is still a very import issue, and it's 
the sort of issue that can probably be implemented with minimal effort. The 
main thing is getting Walter to agree to it and how it will be done. Once a 
decision is made, it wouldn't surprise me if someone like Kenji were able to 
get it done very quickly.

- Jonathan M Davis